[net-next PATCH 0/9] sockmap UAPI updates and fixes

[net-next PATCH 0/9] sockmap UAPI updates and fixes

[John Fastabend]

This series updates sockmap UAPI, adds additional test cases and
provides a couple fixes.

First the UAPI changes. The original API added two sockmap specific
API artifacts (a) a new map_flags field with a sockmap specific update
command and (b) a new sockmap specific attach field in the attach data
structure. After this series instead of attaching programs with a
single command now two commands are used to attach programs to maps
individually. This allows us to add new programs easily in the future
and avoids any specific sockmap data structure additions. The
map_flags field is also removed and instead we allow socks to be
added to multiple maps that may or may not have programs attached.
This allows users to decide if a sock should run a SK_SKB program type
on receive based on the map it is attached to. This is a nice
improvement. See patches for specific details.

More test cases were added to test above changes and also stress test
the interface.

Finally two fixes/improvements were made. First a missing rcu
section was added. Second now sockmap can build without KCM being
used to trigger 'y' on CONFIG_STREAM_PARSER by selecting a new
BPF config option.

---

John Fastabend (9):
      bpf: convert sockmap field attach_bpf_fd2 to type
      bpf: sockmap, remove STRPARSER map_flags and add multi-map support
      bpf: sockmap add missing rcu_read_(un)lock in smap_data_ready
      bpf: additional sockmap self tests
      bpf: more SK_SKB selftests
      bpf: harden sockmap program attach to ensure correct map type
      bpf: sockmap indicate sock events to listeners
      bpf: sockmap requires STREAM_PARSER add Kconfig entry
      bpf: test_maps add sockmap stress test


 include/linux/bpf.h                                |   10 +
 include/uapi/linux/bpf.h                           |   12 -
 kernel/bpf/sockmap.c                               |  312 ++++++++++++--------
 kernel/bpf/syscall.c                               |   38 +-
 net/Kconfig                                        |   12 +
 samples/sockmap/sockmap_kern.c                     |    6 
 samples/sockmap/sockmap_user.c                     |   12 +
 tools/include/uapi/linux/bpf.h                     |    9 -
 tools/lib/bpf/bpf.c                                |   14 -
 tools/lib/bpf/bpf.h                                |    4 
 tools/testing/selftests/bpf/bpf_helpers.h          |    3 
 tools/testing/selftests/bpf/sockmap_parse_prog.c   |    8 -
 tools/testing/selftests/bpf/sockmap_verdict_prog.c |   30 ++
 tools/testing/selftests/bpf/test_maps.c            |  272 +++++++++++------
 tools/testing/selftests/bpf/test_verifier.c        |   98 ++++++
 15 files changed, 544 insertions(+), 296 deletions(-)

[net-next PATCH 1/9] bpf: convert sockmap field attach_bpf_fd2 to type

[John Fastabend]

In the initial sockmap API we provided strparser and verdict programs
using a single attach command by extending the attach API with a the
attach_bpf_fd2 field.

However, if we add other programs in the future we will be adding a
field for every new possible type, attach_bpf_fd(3,4,..). This
seems a bit clumsy for an API. So lets push the programs using two
new type fields.

   BPF_SK_SKB_STREAM_PARSER
   BPF_SK_SKB_STREAM_VERDICT

This has the advantage of having a readable name and can easily be
extended in the future.

Updates to samples and sockmap included here also generalize tests
slightly to support upcoming patch for multiple map support.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support")
Suggested-by: Alexei Starovoitov <ast@kernel.org>
---
 include/linux/bpf.h                                |   10 +-
 include/uapi/linux/bpf.h                           |    9 -
 kernel/bpf/sockmap.c                               |   25 ++--
 kernel/bpf/syscall.c                               |   38 ++----
 samples/sockmap/sockmap_kern.c                     |    6 -
 samples/sockmap/sockmap_user.c                     |   12 ++
 tools/include/uapi/linux/bpf.h                     |    9 -
 tools/lib/bpf/bpf.c                                |   14 --
 tools/lib/bpf/bpf.h                                |    4 -
 tools/testing/selftests/bpf/bpf_helpers.h          |    3 
 tools/testing/selftests/bpf/sockmap_parse_prog.c   |    2 
 tools/testing/selftests/bpf/sockmap_verdict_prog.c |    2 
 tools/testing/selftests/bpf/test_maps.c            |  133 +++++++++-----------
 13 files changed, 116 insertions(+), 151 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 830f472..c2cb1b5 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -39,8 +39,6 @@ struct bpf_map_ops {
 	void (*map_fd_put_ptr)(void *ptr);
 	u32 (*map_gen_lookup)(struct bpf_map *map, struct bpf_insn *insn_buf);
 	u32 (*map_fd_sys_lookup_elem)(void *ptr);
-	int (*map_attach)(struct bpf_map *map,
-			  struct bpf_prog *p1, struct bpf_prog *p2);
 };
 
 struct bpf_map {
@@ -387,11 +385,19 @@ static inline void __dev_map_flush(struct bpf_map *map)
 
 #if defined(CONFIG_STREAM_PARSER) && defined(CONFIG_BPF_SYSCALL)
 struct sock  *__sock_map_lookup_elem(struct bpf_map *map, u32 key);
+int sock_map_attach_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type);
 #else
 static inline struct sock  *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
 {
 	return NULL;
 }
+
+static inline int sock_map_attach_prog(struct bpf_map *map,
+				       struct bpf_prog *prog,
+				       u32 type)
+{
+	return -EOPNOTSUPP;
+}
 #endif
 
 /* verifier prototypes for helper functions called from eBPF programs */
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 843818d..97227be 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -136,7 +136,8 @@ enum bpf_attach_type {
 	BPF_CGROUP_INET_EGRESS,
 	BPF_CGROUP_INET_SOCK_CREATE,
 	BPF_CGROUP_SOCK_OPS,
-	BPF_CGROUP_SMAP_INGRESS,
+	BPF_SK_SKB_STREAM_PARSER,
+	BPF_SK_SKB_STREAM_VERDICT,
 	__MAX_BPF_ATTACH_TYPE
 };
 
@@ -224,7 +225,6 @@ enum bpf_attach_type {
 		__u32		attach_bpf_fd;	/* eBPF program to attach */
 		__u32		attach_type;
 		__u32		attach_flags;
-		__u32		attach_bpf_fd2;
 	};
 
 	struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
@@ -580,14 +580,11 @@ enum bpf_attach_type {
  *     @flags: reserved for future use
  *     Return: SK_REDIRECT
  *
- * int bpf_sock_map_update(skops, map, key, flags, map_flags)
+ * int bpf_sock_map_update(skops, map, key, flags)
  *	@skops: pointer to bpf_sock_ops
  *	@map: pointer to sockmap to update
  *	@key: key to insert/update sock in map
  *	@flags: same flags as map update elem
- *	@map_flags: sock map specific flags
- *	   bit 1: Enable strparser
- *	   other bits: reserved
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 617c239..cf570d1 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -723,20 +723,24 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
 	return err;
 }
 
-static int sock_map_attach_prog(struct bpf_map *map,
-				struct bpf_prog *parse,
-				struct bpf_prog *verdict)
+int sock_map_attach_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type)
 {
 	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
-	struct bpf_prog *_parse, *_verdict;
+	struct bpf_prog *orig;
 
-	_parse = xchg(&stab->bpf_parse, parse);
-	_verdict = xchg(&stab->bpf_verdict, verdict);
+	switch (type) {
+	case BPF_SK_SKB_STREAM_PARSER:
+		orig = xchg(&stab->bpf_parse, prog);
+		break;
+	case BPF_SK_SKB_STREAM_VERDICT:
+		orig = xchg(&stab->bpf_verdict, prog);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
 
-	if (_parse)
-		bpf_prog_put(_parse);
-	if (_verdict)
-		bpf_prog_put(_verdict);
+	if (orig)
+		bpf_prog_put(orig);
 
 	return 0;
 }
@@ -777,7 +781,6 @@ static int sock_map_update_elem(struct bpf_map *map,
 	.map_get_next_key = sock_map_get_next_key,
 	.map_update_elem = sock_map_update_elem,
 	.map_delete_elem = sock_map_delete_elem,
-	.map_attach = sock_map_attach_prog,
 };
 
 BPF_CALL_5(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock,
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 9378f3b..021a05d 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1093,12 +1093,12 @@ static int bpf_obj_get(const union bpf_attr *attr)
 
 #ifdef CONFIG_CGROUP_BPF
 
-#define BPF_PROG_ATTACH_LAST_FIELD attach_bpf_fd2
+#define BPF_PROG_ATTACH_LAST_FIELD attach_flags
 
-static int sockmap_get_from_fd(const union bpf_attr *attr, int ptype)
+static int sockmap_get_from_fd(const union bpf_attr *attr)
 {
-	struct bpf_prog *prog1, *prog2;
 	int ufd = attr->target_fd;
+	struct bpf_prog *prog;
 	struct bpf_map *map;
 	struct fd f;
 	int err;
@@ -1108,29 +1108,16 @@ static int sockmap_get_from_fd(const union bpf_attr *attr, int ptype)
 	if (IS_ERR(map))
 		return PTR_ERR(map);
 
-	if (!map->ops->map_attach) {
-		fdput(f);
-		return -EOPNOTSUPP;
-	}
-
-	prog1 = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
-	if (IS_ERR(prog1)) {
+	prog = bpf_prog_get_type(attr->attach_bpf_fd, BPF_PROG_TYPE_SK_SKB);
+	if (IS_ERR(prog)) {
 		fdput(f);
-		return PTR_ERR(prog1);
-	}
-
-	prog2 = bpf_prog_get_type(attr->attach_bpf_fd2, ptype);
-	if (IS_ERR(prog2)) {
-		fdput(f);
-		bpf_prog_put(prog1);
-		return PTR_ERR(prog2);
+		return PTR_ERR(prog);
 	}
 
-	err = map->ops->map_attach(map, prog1, prog2);
+	err = sock_map_attach_prog(map, prog, attr->attach_type);
 	if (err) {
 		fdput(f);
-		bpf_prog_put(prog1);
-		bpf_prog_put(prog2);
+		bpf_prog_put(prog);
 		return err;
 	}
 
@@ -1165,16 +1152,13 @@ static int bpf_prog_attach(const union bpf_attr *attr)
 	case BPF_CGROUP_SOCK_OPS:
 		ptype = BPF_PROG_TYPE_SOCK_OPS;
 		break;
-	case BPF_CGROUP_SMAP_INGRESS:
-		ptype = BPF_PROG_TYPE_SK_SKB;
-		break;
+	case BPF_SK_SKB_STREAM_PARSER:
+	case BPF_SK_SKB_STREAM_VERDICT:
+		return sockmap_get_from_fd(attr);
 	default:
 		return -EINVAL;
 	}
 
-	if (attr->attach_type == BPF_CGROUP_SMAP_INGRESS)
-		return sockmap_get_from_fd(attr, ptype);
-
 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
 	if (IS_ERR(prog))
 		return PTR_ERR(prog);
diff --git a/samples/sockmap/sockmap_kern.c b/samples/sockmap/sockmap_kern.c
index 6ff986f..f9b38ef 100644
--- a/samples/sockmap/sockmap_kern.c
+++ b/samples/sockmap/sockmap_kern.c
@@ -82,8 +82,7 @@ int bpf_sockmap(struct bpf_sock_ops *skops)
 		if (lport == 10000) {
 			ret = 1;
 			err = bpf_sock_map_update(skops, &sock_map, &ret,
-						  BPF_NOEXIST,
-						  BPF_SOCKMAP_STRPARSER);
+						  BPF_NOEXIST);
 			bpf_printk("passive(%i -> %i) map ctx update err: %d\n",
 				   lport, bpf_ntohl(rport), err);
 		}
@@ -95,8 +94,7 @@ int bpf_sockmap(struct bpf_sock_ops *skops)
 		if (bpf_ntohl(rport) == 10001) {
 			ret = 10;
 			err = bpf_sock_map_update(skops, &sock_map, &ret,
-						  BPF_NOEXIST,
-						  BPF_SOCKMAP_STRPARSER);
+						  BPF_NOEXIST);
 			bpf_printk("active(%i -> %i) map ctx update err: %d\n",
 				   lport, bpf_ntohl(rport), err);
 		}
diff --git a/samples/sockmap/sockmap_user.c b/samples/sockmap/sockmap_user.c
index fb78f5a..7cc9d22 100644
--- a/samples/sockmap/sockmap_user.c
+++ b/samples/sockmap/sockmap_user.c
@@ -256,8 +256,16 @@ int main(int argc, char **argv)
 	}
 
 	/* Attach programs to sockmap */
-	err = __bpf_prog_attach(prog_fd[0], prog_fd[1], map_fd[0],
-				BPF_CGROUP_SMAP_INGRESS, 0);
+	err = bpf_prog_attach(prog_fd[0], map_fd[0],
+				BPF_SK_SKB_STREAM_PARSER, 0);
+	if (err) {
+		fprintf(stderr, "ERROR: bpf_prog_attach (sockmap): %d (%s)\n",
+			err, strerror(errno));
+		return err;
+	}
+
+	err = bpf_prog_attach(prog_fd[1], map_fd[0],
+				BPF_SK_SKB_STREAM_VERDICT, 0);
 	if (err) {
 		fprintf(stderr, "ERROR: bpf_prog_attach (sockmap): %d (%s)\n",
 			err, strerror(errno));
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index f8f6377..09ac590 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -136,7 +136,8 @@ enum bpf_attach_type {
 	BPF_CGROUP_INET_EGRESS,
 	BPF_CGROUP_INET_SOCK_CREATE,
 	BPF_CGROUP_SOCK_OPS,
-	BPF_CGROUP_SMAP_INGRESS,
+	BPF_SK_SKB_STREAM_PARSER,
+	BPF_SK_SKB_STREAM_VERDICT,
 	__MAX_BPF_ATTACH_TYPE
 };
 
@@ -227,7 +228,6 @@ enum bpf_sockmap_flags {
 		__u32		attach_bpf_fd;	/* eBPF program to attach */
 		__u32		attach_type;
 		__u32		attach_flags;
-		__u32		attach_bpf_fd2;
 	};
 
 	struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
@@ -572,14 +572,11 @@ enum bpf_sockmap_flags {
  *     @flags: reserved for future use
  *     Return: SK_REDIRECT
  *
- * int bpf_sock_map_update(skops, map, key, flags, map_flags)
+ * int bpf_sock_map_update(skops, map, key, flags)
  *	@skops: pointer to bpf_sock_ops
  *	@map: pointer to sockmap to update
  *	@key: key to insert/update sock in map
  *	@flags: same flags as map update elem
- *	@map_flags: sock map specific flags
- *	   bit 1: Enable strparser
- *	   other bits: reserved
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index a071761..1d6907d 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -235,28 +235,20 @@ int bpf_obj_get(const char *pathname)
 	return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr));
 }
 
-int __bpf_prog_attach(int prog_fd1, int prog_fd2, int target_fd,
-		      enum bpf_attach_type type,
-		      unsigned int flags)
+int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
+		    unsigned int flags)
 {
 	union bpf_attr attr;
 
 	bzero(&attr, sizeof(attr));
 	attr.target_fd	   = target_fd;
-	attr.attach_bpf_fd = prog_fd1;
-	attr.attach_bpf_fd2 = prog_fd2;
+	attr.attach_bpf_fd = prog_fd;
 	attr.attach_type   = type;
 	attr.attach_flags  = flags;
 
 	return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr));
 }
 
-int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
-		    unsigned int flags)
-{
-	return __bpf_prog_attach(prog_fd, 0, target_fd, type, flags);
-}
-
 int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
 {
 	union bpf_attr attr;
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 90e9d4e..b8ea584 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -56,10 +56,6 @@ int bpf_map_update_elem(int fd, const void *key, const void *value,
 int bpf_obj_get(const char *pathname);
 int bpf_prog_attach(int prog_fd, int attachable_fd, enum bpf_attach_type type,
 		    unsigned int flags);
-int __bpf_prog_attach(int prog1, int prog2,
-		      int attachable_fd,
-		      enum bpf_attach_type type,
-		      unsigned int flags);
 int bpf_prog_detach(int attachable_fd, enum bpf_attach_type type);
 int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
 		      void *data_out, __u32 *size_out, __u32 *retval,
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h
index 98f3be2..36fb916 100644
--- a/tools/testing/selftests/bpf/bpf_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_helpers.h
@@ -68,8 +68,7 @@ static int (*bpf_setsockopt)(void *ctx, int level, int optname, void *optval,
 static int (*bpf_sk_redirect_map)(void *map, int key, int flags) =
 	(void *) BPF_FUNC_sk_redirect_map;
 static int (*bpf_sock_map_update)(void *map, void *key, void *value,
-				  unsigned long long flags,
-				  unsigned long long map_lags) =
+				  unsigned long long flags) =
 	(void *) BPF_FUNC_sock_map_update;
 
 
diff --git a/tools/testing/selftests/bpf/sockmap_parse_prog.c b/tools/testing/selftests/bpf/sockmap_parse_prog.c
index 8b54531..710f43f 100644
--- a/tools/testing/selftests/bpf/sockmap_parse_prog.c
+++ b/tools/testing/selftests/bpf/sockmap_parse_prog.c
@@ -30,7 +30,7 @@ int bpf_prog1(struct __sk_buff *skb)
 	 */
 	d[0] = 1;
 
-	bpf_printk("data[0] = (%u): local_port %i remote %i\n",
+	bpf_printk("parse: data[0] = (%u): local_port %i remote %i\n",
 		   d[0], lport, bpf_ntohl(rport));
 	return skb->len;
 }
diff --git a/tools/testing/selftests/bpf/sockmap_verdict_prog.c b/tools/testing/selftests/bpf/sockmap_verdict_prog.c
index d5f9447..0573c1d 100644
--- a/tools/testing/selftests/bpf/sockmap_verdict_prog.c
+++ b/tools/testing/selftests/bpf/sockmap_verdict_prog.c
@@ -40,7 +40,7 @@ int bpf_prog2(struct __sk_buff *skb)
 	d[6] = 0xe;
 	d[7] = 0xf;
 
-	bpf_printk("data[0] = (%u): local_port %i remote %i\n",
+	bpf_printk("verdict: data[0] = (%u): local_port %i remote %i redirect 5\n",
 		   d[0], lport, bpf_ntohl(rport));
 	return bpf_sk_redirect_map(&sock_map, 5, 0);
 }
diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index 40b2d1f..6df6e62 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -547,20 +547,26 @@ static void test_sockmap(int task, void *data)
 		goto out_sockmap;
 	}
 
-	/* Nothing attached so these should fail */
+	/* Test update without programs */
 	for (i = 0; i < 6; i++) {
 		err = bpf_map_update_elem(fd, &i, &sfd[i], BPF_ANY);
-		if (!err) {
-			printf("Failed invalid update sockmap '%i:%i'\n",
+		if (err) {
+			printf("Failed noprog update sockmap '%i:%i'\n",
 			       i, sfd[i]);
 			goto out_sockmap;
 		}
 	}
 
 	/* Test attaching bad fds */
-	err = __bpf_prog_attach(-1, -2, fd, BPF_CGROUP_SMAP_INGRESS, 0);
+	err = bpf_prog_attach(-1, fd, BPF_SK_SKB_STREAM_PARSER, 0);
 	if (!err) {
-		printf("Failed invalid prog attach\n");
+		printf("Failed invalid parser prog attach\n");
+		goto out_sockmap;
+	}
+
+	err = bpf_prog_attach(-1, fd, BPF_SK_SKB_STREAM_VERDICT, 0);
+	if (!err) {
+		printf("Failed invalid verdict prog attach\n");
 		goto out_sockmap;
 	}
 
@@ -591,14 +597,21 @@ static void test_sockmap(int task, void *data)
 		goto out_sockmap;
 	}
 
-	err = __bpf_prog_attach(parse_prog, verdict_prog, map_fd,
-				BPF_CGROUP_SMAP_INGRESS, 0);
+	err = bpf_prog_attach(parse_prog, map_fd,
+		      BPF_SK_SKB_STREAM_PARSER, 0);
+	if (err) {
+		printf("Failed bpf prog attach\n");
+		goto out_sockmap;
+	}
+
+	err = bpf_prog_attach(verdict_prog, map_fd,
+			      BPF_SK_SKB_STREAM_VERDICT, 0);
 	if (err) {
 		printf("Failed bpf prog attach\n");
 		goto out_sockmap;
 	}
 
-	/* Test map update elem */
+	/* Test map update elem afterwards fd lives in fd and map_fd */
 	for (i = 0; i < 6; i++) {
 		err = bpf_map_update_elem(map_fd, &i, &sfd[i], BPF_ANY);
 		if (err) {
@@ -649,96 +662,68 @@ static void test_sockmap(int task, void *data)
 		goto out_sockmap;
 	}
 
-	/* Delete the reset of the elems include some NULL elems */
-	for (i = 0; i < 6; i++) {
-		err = bpf_map_delete_elem(map_fd, &i);
-		if (err && (i == 0 || i == 1 || i >= 4)) {
-			printf("Failed delete  sockmap %i '%i:%i'\n",
-			       err, i, sfd[i]);
-			goto out_sockmap;
-		} else if (!err && (i == 2 || i == 3)) {
-			printf("Failed null delete sockmap %i '%i:%i'\n",
-			       err, i, sfd[i]);
-			goto out_sockmap;
-		}
-	}
-
-	/* Test having multiple SMAPs open and active on same fds */
-	err = __bpf_prog_attach(parse_prog, verdict_prog, fd,
-				BPF_CGROUP_SMAP_INGRESS, 0);
-	if (err) {
-		printf("Failed fd bpf prog attach\n");
-		goto out_sockmap;
-	}
-
-	for (i = 0; i < 6; i++) {
-		err = bpf_map_update_elem(fd, &i, &sfd[i], BPF_ANY);
-		if (err) {
-			printf("Failed fd update sockmap %i '%i:%i'\n",
-			       err, i, sfd[i]);
-			goto out_sockmap;
-		}
-	}
-
-	/* Test duplicate socket add of NOEXIST, ANY and EXIST */
-	i = 0;
+	/* Push fd into same slot */
+	i = 2;
 	err = bpf_map_update_elem(fd, &i, &sfd[i], BPF_NOEXIST);
 	if (!err) {
-		printf("Failed BPF_NOEXIST create\n");
+		printf("Failed allowed sockmap dup slot BPF_NOEXIST\n");
 		goto out_sockmap;
 	}
 
 	err = bpf_map_update_elem(fd, &i, &sfd[i], BPF_ANY);
 	if (err) {
-		printf("Failed sockmap update BPF_ANY\n");
+		printf("Failed sockmap update new slot BPF_ANY\n");
 		goto out_sockmap;
 	}
 
 	err = bpf_map_update_elem(fd, &i, &sfd[i], BPF_EXIST);
 	if (err) {
-		printf("Failed sockmap update BPF_EXIST\n");
+		printf("Failed sockmap update new slot BPF_EXIST\n");
 		goto out_sockmap;
 	}
 
-	/* The above were pushing fd into same slot try different slot now */
-	i = 2;
-	err = bpf_map_update_elem(fd, &i, &sfd[i], BPF_NOEXIST);
-	if (!err) {
-		printf("Failed BPF_NOEXIST create\n");
-		goto out_sockmap;
+	/* Delete the elems without programs */
+	for (i = 0; i < 6; i++) {
+		err = bpf_map_delete_elem(fd, &i);
+		if (err) {
+			printf("Failed delete sockmap %i '%i:%i'\n",
+			       err, i, sfd[i]);
+		}
 	}
 
-	err = bpf_map_update_elem(fd, &i, &sfd[i], BPF_ANY);
+	/* Test having multiple maps open and set with programs on same fds */
+	err = bpf_prog_attach(parse_prog, fd,
+			      BPF_SK_SKB_STREAM_PARSER, 0);
 	if (err) {
-		printf("Failed sockmap update BPF_ANY\n");
+		printf("Failed fd bpf parse prog attach\n");
 		goto out_sockmap;
 	}
-
-	err = bpf_map_update_elem(fd, &i, &sfd[i], BPF_EXIST);
+	err = bpf_prog_attach(verdict_prog, fd,
+			      BPF_SK_SKB_STREAM_VERDICT, 0);
 	if (err) {
-		printf("Failed sockmap update BPF_EXIST\n");
+		printf("Failed fd bpf verdict prog attach\n");
 		goto out_sockmap;
 	}
 
-	/* Try pushing fd into different map, this is not allowed at the
-	 * moment. Which programs would we use?
-	 */
-	err = bpf_map_update_elem(map_fd, &i, &sfd[i], BPF_NOEXIST);
-	if (!err) {
-		printf("Failed BPF_NOEXIST create\n");
-		goto out_sockmap;
-	}
-
-	err = bpf_map_update_elem(map_fd, &i, &sfd[i], BPF_ANY);
-	if (!err) {
-		printf("Failed sockmap update BPF_ANY\n");
-		goto out_sockmap;
-	}
-
-	err = bpf_map_update_elem(map_fd, &i, &sfd[i], BPF_EXIST);
-	if (!err) {
-		printf("Failed sockmap update BPF_EXIST\n");
-		goto out_sockmap;
+	for (i = 4; i < 6; i++) {
+		err = bpf_map_update_elem(fd, &i, &sfd[i], BPF_ANY);
+		if (!err) {
+			printf("Failed allowed duplicate programs in update ANY sockmap %i '%i:%i'\n",
+			       err, i, sfd[i]);
+			goto out_sockmap;
+		}
+		err = bpf_map_update_elem(fd, &i, &sfd[i], BPF_NOEXIST);
+		if (!err) {
+			printf("Failed allowed duplicate program in update NOEXIST sockmap  %i '%i:%i'\n",
+			       err, i, sfd[i]);
+			goto out_sockmap;
+		}
+		err = bpf_map_update_elem(fd, &i, &sfd[i], BPF_EXIST);
+		if (!err) {
+			printf("Failed allowed duplicate program in update EXIST sockmap  %i '%i:%i'\n",
+			       err, i, sfd[i]);
+			goto out_sockmap;
+		}
 	}
 
 	/* Test map close sockets */

Re: [net-next PATCH 1/9] bpf: convert sockmap field attach_bpf_fd2 to type

[Alexei Starovoitov]

On Mon, Aug 28, 2017 at 07:10:04AM -0700, John Fastabend wrote:
> In the initial sockmap API we provided strparser and verdict programs
> using a single attach command by extending the attach API with a the
> attach_bpf_fd2 field.
> 
> However, if we add other programs in the future we will be adding a
> field for every new possible type, attach_bpf_fd(3,4,..). This
> seems a bit clumsy for an API. So lets push the programs using two
> new type fields.
> 
>    BPF_SK_SKB_STREAM_PARSER
>    BPF_SK_SKB_STREAM_VERDICT
> 
> This has the advantage of having a readable name and can easily be
> extended in the future.
> 
> Updates to samples and sockmap included here also generalize tests
> slightly to support upcoming patch for multiple map support.
> 
> Signed-off-by: John Fastabend <john.fastabend@gmail.com>
> Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support")
> Suggested-by: Alexei Starovoitov <ast@kernel.org>

lgtm
Acked-by: Alexei Starovoitov <ast@kernel.org>

[net-next PATCH 2/9] bpf: sockmap, remove STRPARSER map_flags and add multi-map support

[John Fastabend]

The addition of map_flags BPF_SOCKMAP_STRPARSER flags was to handle a
specific use case where we want to have BPF parse program disabled on
an entry in a sockmap.

However, Alexei found the API a bit cumbersome and I agreed. Lets
remove the STRPARSER flag and support the use case by allowing socks
to be in multiple maps. This allows users to create two maps one with
programs attached and one without. When socks are added to maps they
now inherit any programs attached to the map. This is a nice
generalization and IMO improves the API.

The API rules are less ambiguous and do not need a flag:

  - When a sock is added to a sockmap we have two cases,

     i. The sock map does not have any attached programs so
        we can add sock to map without inheriting bpf programs.
        The sock may exist in 0 or more other maps.

    ii. The sock map has an attached BPF program. To avoid duplicate
        bpf programs we only add the sock entry if it does not have
        an existing strparser/verdict attached, returning -EBUSY if
        a program is already attached. Otherwise attach the program
        and inherit strparser/verdict programs from the sock map.

This allows for socks to be in a multiple maps for redirects and
inherit a BPF program from a single map.

Also this patch simplifies the logic around BPF_{EXIST|NOEXIST|ANY}
flags. In the original patch I tried to be extra clever and only
update map entries when necessary. Now I've decided the complexity
is not worth it. If users constantly update an entry with the same
sock for no reason (i.e. update an entry without actually changing
any parameters on map or sock) we still do an alloc/release. Using
this and allowing multiple entries of a sock to exist in a map the
logic becomes much simpler.

Note: Now that multiple maps are supported the "maps" pointer called
when a socket is closed becomes a list of maps to remove the sock from.
To keep the map up to date when a sock is added to the sockmap we must
add the map/elem in the list. Likewise when it is removed we must
remove it from the list. This results in searching the per psock list
on delete operation. On TCP_CLOSE events we walk the list and remove
the psock from all map/entry locations. I don't see any perf
implications in this because at most I have a psock in two maps. If
a psock were to be in many maps its possibly this might be noticeable
on delete but I can't think of a reason to dup a psock in many maps.
The sk_callback_lock is used to protect read/writes to the list. This
was convenient because in all locations we were taking the lock
anyways just after working on the list. Also the lock is per sock so
in normal cases we shouldn't see any contention.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 include/uapi/linux/bpf.h |    3 -
 kernel/bpf/sockmap.c     |  269 ++++++++++++++++++++++++++++------------------
 2 files changed, 165 insertions(+), 107 deletions(-)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 97227be..08c206a 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -143,9 +143,6 @@ enum bpf_attach_type {
 
 #define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
 
-/* If BPF_SOCKMAP_STRPARSER is used sockmap will use strparser on receive */
-#define BPF_SOCKMAP_STRPARSER	(1U << 0)
-
 /* If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command
  * to the given target_fd cgroup the descendent cgroup will be able to
  * override effective bpf program that was inherited from this cgroup
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index cf570d1..a6882e5 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -13,15 +13,16 @@
 /* A BPF sock_map is used to store sock objects. This is primarly used
  * for doing socket redirect with BPF helper routines.
  *
- * A sock map may have two BPF programs attached to it, a program used
- * to parse packets and a program to provide a verdict and redirect
- * decision on the packet. If no BPF parse program is provided it is
- * assumed that every skb is a "message" (skb->len). Otherwise the
- * parse program is attached to strparser and used to build messages
- * that may span multiple skbs. The verdict program will either select
- * a socket to send/receive the skb on or provide the drop code indicating
- * the skb should be dropped. More actions may be added later as needed.
- * The default program will drop packets.
+ * A sock map may have BPF programs attached to it, currently a program
+ * used to parse packets and a program to provide a verdict and redirect
+ * decision on the packet are supported. Any programs attached to a sock
+ * map are inherited by sock objects when they are added to the map. If
+ * no BPF programs are attached the sock object may only be used for sock
+ * redirect.
+ *
+ * A sock object may be in multiple maps, but can only inherit a single
+ * parse or verdict program. If adding a sock object to a map would result
+ * in having multiple parsing programs the update will return an EBUSY error.
  *
  * For reference this program is similar to devmap used in XDP context
  * reviewing these together may be useful. For an example please review
@@ -44,15 +45,21 @@ struct bpf_stab {
 	struct sock **sock_map;
 	struct bpf_prog *bpf_parse;
 	struct bpf_prog *bpf_verdict;
-	refcount_t refcnt;
 };
 
 enum smap_psock_state {
 	SMAP_TX_RUNNING,
 };
 
+struct smap_psock_map_entry {
+	struct list_head list;
+	struct sock **entry;
+};
+
 struct smap_psock {
 	struct rcu_head	rcu;
+	/* refcnt is used inside sk_callback_lock */
+	u32 refcnt;
 
 	/* datapath variables */
 	struct sk_buff_head rxqueue;
@@ -66,10 +73,9 @@ struct smap_psock {
 	struct strparser strp;
 	struct bpf_prog *bpf_parse;
 	struct bpf_prog *bpf_verdict;
-	struct bpf_stab *stab;
+	struct list_head maps;
 
 	/* Back reference used when sock callback trigger sockmap operations */
-	int key;
 	struct sock *sock;
 	unsigned long state;
 
@@ -83,7 +89,7 @@ struct smap_psock {
 
 static inline struct smap_psock *smap_psock_sk(const struct sock *sk)
 {
-	return (struct smap_psock *)rcu_dereference_sk_user_data(sk);
+	return rcu_dereference_sk_user_data(sk);
 }
 
 static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb)
@@ -149,11 +155,12 @@ static void smap_report_sk_error(struct smap_psock *psock, int err)
 	sk->sk_error_report(sk);
 }
 
-static void smap_release_sock(struct sock *sock);
+static void smap_release_sock(struct smap_psock *psock, struct sock *sock);
 
 /* Called with lock_sock(sk) held */
 static void smap_state_change(struct sock *sk)
 {
+	struct smap_psock_map_entry *e, *tmp;
 	struct smap_psock *psock;
 	struct sock *osk;
 
@@ -184,9 +191,15 @@ static void smap_state_change(struct sock *sk)
 		psock = smap_psock_sk(sk);
 		if (unlikely(!psock))
 			break;
-		osk = cmpxchg(&psock->stab->sock_map[psock->key], sk, NULL);
-		if (osk == sk)
-			smap_release_sock(sk);
+		write_lock_bh(&sk->sk_callback_lock);
+		list_for_each_entry_safe(e, tmp, &psock->maps, list) {
+			osk = cmpxchg(e->entry, sk, NULL);
+			if (osk == sk) {
+				list_del(&e->list);
+				smap_release_sock(psock, sk);
+			}
+		}
+		write_unlock_bh(&sk->sk_callback_lock);
 		break;
 	default:
 		psock = smap_psock_sk(sk);
@@ -289,9 +302,8 @@ static void smap_write_space(struct sock *sk)
 
 static void smap_stop_sock(struct smap_psock *psock, struct sock *sk)
 {
-	write_lock_bh(&sk->sk_callback_lock);
 	if (!psock->strp_enabled)
-		goto out;
+		return;
 	sk->sk_data_ready = psock->save_data_ready;
 	sk->sk_write_space = psock->save_write_space;
 	sk->sk_state_change = psock->save_state_change;
@@ -300,8 +312,6 @@ static void smap_stop_sock(struct smap_psock *psock, struct sock *sk)
 	psock->save_state_change = NULL;
 	strp_stop(&psock->strp);
 	psock->strp_enabled = false;
-out:
-	write_unlock_bh(&sk->sk_callback_lock);
 }
 
 static void smap_destroy_psock(struct rcu_head *rcu)
@@ -318,9 +328,11 @@ static void smap_destroy_psock(struct rcu_head *rcu)
 	schedule_work(&psock->gc_work);
 }
 
-static void smap_release_sock(struct sock *sock)
+static void smap_release_sock(struct smap_psock *psock, struct sock *sock)
 {
-	struct smap_psock *psock = smap_psock_sk(sock);
+	psock->refcnt--;
+	if (psock->refcnt)
+		return;
 
 	smap_stop_sock(psock, sock);
 	clear_bit(SMAP_TX_RUNNING, &psock->state);
@@ -414,6 +426,7 @@ static void sock_map_remove_complete(struct bpf_stab *stab)
 
 static void smap_gc_work(struct work_struct *w)
 {
+	struct smap_psock_map_entry *e, *tmp;
 	struct smap_psock *psock;
 
 	psock = container_of(w, struct smap_psock, gc_work);
@@ -431,8 +444,10 @@ static void smap_gc_work(struct work_struct *w)
 	if (psock->bpf_verdict)
 		bpf_prog_put(psock->bpf_verdict);
 
-	if (refcount_dec_and_test(&psock->stab->refcnt))
-		sock_map_remove_complete(psock->stab);
+	list_for_each_entry_safe(e, tmp, &psock->maps, list) {
+		list_del(&e->list);
+		kfree(e);
+	}
 
 	sock_put(psock->sock);
 	kfree(psock);
@@ -453,6 +468,8 @@ static struct smap_psock *smap_init_psock(struct sock *sock,
 	skb_queue_head_init(&psock->rxqueue);
 	INIT_WORK(&psock->tx_work, smap_tx_work);
 	INIT_WORK(&psock->gc_work, smap_gc_work);
+	INIT_LIST_HEAD(&psock->maps);
+	psock->refcnt = 1;
 
 	rcu_assign_sk_user_data(sock, psock);
 	sock_hold(sock);
@@ -503,13 +520,24 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
 	if (!stab->sock_map)
 		goto free_stab;
 
-	refcount_set(&stab->refcnt, 1);
 	return &stab->map;
 free_stab:
 	kfree(stab);
 	return ERR_PTR(err);
 }
 
+static void smap_list_remove(struct smap_psock *psock, struct sock **entry)
+{
+	struct smap_psock_map_entry *e, *tmp;
+
+	list_for_each_entry_safe(e, tmp, &psock->maps, list) {
+		if (e->entry == entry) {
+			list_del(&e->list);
+			break;
+		}
+	}
+}
+
 static void sock_map_free(struct bpf_map *map)
 {
 	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
@@ -526,13 +554,18 @@ static void sock_map_free(struct bpf_map *map)
 	 */
 	rcu_read_lock();
 	for (i = 0; i < stab->map.max_entries; i++) {
+		struct smap_psock *psock;
 		struct sock *sock;
 
 		sock = xchg(&stab->sock_map[i], NULL);
 		if (!sock)
 			continue;
 
-		smap_release_sock(sock);
+		write_lock_bh(&sock->sk_callback_lock);
+		psock = smap_psock_sk(sock);
+		smap_list_remove(psock, &stab->sock_map[i]);
+		smap_release_sock(psock, sock);
+		write_unlock_bh(&sock->sk_callback_lock);
 	}
 	rcu_read_unlock();
 
@@ -541,8 +574,7 @@ static void sock_map_free(struct bpf_map *map)
 	if (stab->bpf_parse)
 		bpf_prog_put(stab->bpf_parse);
 
-	if (refcount_dec_and_test(&stab->refcnt))
-		sock_map_remove_complete(stab);
+	sock_map_remove_complete(stab);
 }
 
 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
@@ -576,6 +608,7 @@ struct sock  *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
 static int sock_map_delete_elem(struct bpf_map *map, void *key)
 {
 	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+	struct smap_psock *psock;
 	int k = *(u32 *)key;
 	struct sock *sock;
 
@@ -586,7 +619,17 @@ static int sock_map_delete_elem(struct bpf_map *map, void *key)
 	if (!sock)
 		return -EINVAL;
 
-	smap_release_sock(sock);
+	write_lock_bh(&sock->sk_callback_lock);
+	psock = smap_psock_sk(sock);
+	if (!psock)
+		goto out;
+
+	if (psock->bpf_parse)
+		smap_stop_sock(psock, sock);
+	smap_list_remove(psock, &stab->sock_map[k]);
+	smap_release_sock(psock, sock);
+out:
+	write_unlock_bh(&sock->sk_callback_lock);
 	return 0;
 }
 
@@ -601,29 +644,34 @@ static int sock_map_delete_elem(struct bpf_map *map, void *key)
  * and syncd so we are certain all references from the update/lookup/delete
  * operations as well as references in the data path are no longer in use.
  *
- * A psock object holds a refcnt on the sockmap it is attached to and this is
- * not decremented until after a RCU grace period and garbage collection occurs.
- * This ensures the map is not free'd until psocks linked to it are removed. The
- * map link is used when the independent sock events trigger map deletion.
+ * Psocks may exist in multiple maps, but only a single set of parse/verdict
+ * programs may be inherited from the maps it belongs to. A reference count
+ * is kept with the total number of references to the psock from all maps. The
+ * psock will not be released until this reaches zero. The psock and sock
+ * user data data use the sk_callback_lock to protect critical data structures
+ * from concurrent access. This allows us to avoid two updates from modifying
+ * the user data in sock and the lock is required anyways for modifying
+ * callbacks, we simply increase its scope slightly.
  *
- * Psocks may only participate in one sockmap at a time. Users that try to
- * join a single sock to multiple maps will get an error.
- *
- * Last, but not least, it is possible the socket is closed while running
- * an update on an existing psock. This will release the psock, but again
- * not until the update has completed due to rcu grace period rules.
+ * Rules to follow,
+ *  - psock must always be read inside RCU critical section
+ *  - sk_user_data must only be modified inside sk_callback_lock and read
+ *    inside RCU critical section.
+ *  - psock->maps list must only be read & modified inside sk_callback_lock
+ *  - sock_map must use READ_ONCE and (cmp)xchg operations
+ *  - BPF verdict/parse programs must use READ_ONCE and xchg operations
  */
 static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
 				    struct bpf_map *map,
-				    void *key, u64 flags, u64 map_flags)
+				    void *key, u64 flags)
 {
 	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+	struct smap_psock_map_entry *e = NULL;
 	struct bpf_prog *verdict, *parse;
-	struct smap_psock *psock = NULL;
-	struct sock *old_sock, *sock;
+	struct sock *osock, *sock;
+	struct smap_psock *psock;
 	u32 i = *(u32 *)key;
-	bool update = false;
-	int err = 0;
+	int err;
 
 	if (unlikely(flags > BPF_EXIST))
 		return -EINVAL;
@@ -631,35 +679,22 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
 	if (unlikely(i >= stab->map.max_entries))
 		return -E2BIG;
 
-	if (unlikely(map_flags > BPF_SOCKMAP_STRPARSER))
-		return -EINVAL;
-
-	verdict = parse = NULL;
 	sock = READ_ONCE(stab->sock_map[i]);
-
-	if (flags == BPF_EXIST || flags == BPF_ANY) {
-		if (!sock && flags == BPF_EXIST) {
-			return -ENOENT;
-		} else if (sock && sock != skops->sk) {
-			return -EINVAL;
-		} else if (sock) {
-			psock = smap_psock_sk(sock);
-			if (unlikely(!psock))
-				return -EBUSY;
-			update = true;
-		}
-	} else if (sock && BPF_NOEXIST) {
+	if (flags == BPF_EXIST && !sock)
+		return -ENOENT;
+	else if (flags == BPF_NOEXIST && sock)
 		return -EEXIST;
-	}
 
-	/* reserve BPF programs early so can abort easily on failures */
-	if (map_flags & BPF_SOCKMAP_STRPARSER) {
-		verdict = READ_ONCE(stab->bpf_verdict);
-		parse = READ_ONCE(stab->bpf_parse);
+	sock = skops->sk;
 
-		if (!verdict || !parse)
-			return -ENOENT;
+	/* 1. If sock map has BPF programs those will be inherited by the
+	 * sock being added. If the sock is already attached to BPF programs
+	 * this results in an error.
+	 */
+	verdict = READ_ONCE(stab->bpf_verdict);
+	parse = READ_ONCE(stab->bpf_parse);
 
+	if (parse && verdict) {
 		/* bpf prog refcnt may be zero if a concurrent attach operation
 		 * removes the program after the above READ_ONCE() but before
 		 * we increment the refcnt. If this is the case abort with an
@@ -676,50 +711,78 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
 		}
 	}
 
-	if (!psock) {
-		sock = skops->sk;
-		if (rcu_dereference_sk_user_data(sock))
-			return -EEXIST;
+	write_lock_bh(&sock->sk_callback_lock);
+	psock = smap_psock_sk(sock);
+
+	/* 2. Do not allow inheriting programs if psock exists and has
+	 * already inherited programs. This would create confusion on
+	 * which parser/verdict program is running. If no psock exists
+	 * create one. Inside sk_callback_lock to ensure concurrent create
+	 * doesn't update user data.
+	 */
+	if (psock) {
+		if (READ_ONCE(psock->bpf_parse) && parse) {
+			err = -EBUSY;
+			goto out_progs;
+		}
+		psock->refcnt++;
+	} else {
 		psock = smap_init_psock(sock, stab);
 		if (IS_ERR(psock)) {
-			if (verdict)
-				bpf_prog_put(verdict);
-			if (parse)
-				bpf_prog_put(parse);
-			return PTR_ERR(psock);
+			err = PTR_ERR(psock);
+			goto out_progs;
 		}
-		psock->key = i;
-		psock->stab = stab;
-		refcount_inc(&stab->refcnt);
+
 		set_bit(SMAP_TX_RUNNING, &psock->state);
 	}
 
-	if (map_flags & BPF_SOCKMAP_STRPARSER) {
-		write_lock_bh(&sock->sk_callback_lock);
-		if (psock->strp_enabled)
-			goto start_done;
+	e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN);
+	if (!e) {
+		err = -ENOMEM;
+		goto out_progs;
+	}
+	e->entry = &stab->sock_map[i];
+
+	/* 3. At this point we have a reference to a valid psock that is
+	 * running. Attach any BPF programs needed.
+	 */
+	if (parse && verdict && !psock->strp_enabled) {
 		err = smap_init_sock(psock, sock);
 		if (err)
-			goto out;
+			goto out_free;
 		smap_init_progs(psock, stab, verdict, parse);
 		smap_start_sock(psock, sock);
-start_done:
-		write_unlock_bh(&sock->sk_callback_lock);
-	} else if (update) {
-		smap_stop_sock(psock, sock);
 	}
 
-	if (!update) {
-		old_sock = xchg(&stab->sock_map[i], skops->sk);
-		if (old_sock)
-			smap_release_sock(old_sock);
-	}
+	/* 4. Place psock in sockmap for use and stop any programs on
+	 * the old sock assuming its not the same sock we are replacing
+	 * it with. Because we can only have a single set of programs if
+	 * old_sock has a strp we can stop it.
+	 */
+	list_add_tail(&e->list, &psock->maps);
+	write_unlock_bh(&sock->sk_callback_lock);
 
+	osock = xchg(&stab->sock_map[i], sock);
+	if (osock) {
+		struct smap_psock *opsock = smap_psock_sk(osock);
+
+		write_lock_bh(&osock->sk_callback_lock);
+		if (osock != sock && parse)
+			smap_stop_sock(opsock, osock);
+		smap_list_remove(opsock, &stab->sock_map[i]);
+		smap_release_sock(opsock, osock);
+		write_unlock_bh(&osock->sk_callback_lock);
+	}
 	return 0;
-out:
+out_free:
+	smap_release_sock(psock, sock);
+out_progs:
+	if (verdict)
+		bpf_prog_put(verdict);
+	if (parse)
+		bpf_prog_put(parse);
 	write_unlock_bh(&sock->sk_callback_lock);
-	if (!update)
-		smap_release_sock(sock);
+	kfree(e);
 	return err;
 }
 
@@ -768,8 +831,7 @@ static int sock_map_update_elem(struct bpf_map *map,
 		return -EINVAL;
 	}
 
-	err = sock_map_ctx_update_elem(&skops, map, key,
-				       flags, BPF_SOCKMAP_STRPARSER);
+	err = sock_map_ctx_update_elem(&skops, map, key, flags);
 	fput(socket->file);
 	return err;
 }
@@ -783,11 +845,11 @@ static int sock_map_update_elem(struct bpf_map *map,
 	.map_delete_elem = sock_map_delete_elem,
 };
 
-BPF_CALL_5(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock,
-	   struct bpf_map *, map, void *, key, u64, flags, u64, map_flags)
+BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock,
+	   struct bpf_map *, map, void *, key, u64, flags)
 {
 	WARN_ON_ONCE(!rcu_read_lock_held());
-	return sock_map_ctx_update_elem(bpf_sock, map, key, flags, map_flags);
+	return sock_map_ctx_update_elem(bpf_sock, map, key, flags);
 }
 
 const struct bpf_func_proto bpf_sock_map_update_proto = {
@@ -799,5 +861,4 @@ static int sock_map_update_elem(struct bpf_map *map,
 	.arg2_type	= ARG_CONST_MAP_PTR,
 	.arg3_type	= ARG_PTR_TO_MAP_KEY,
 	.arg4_type	= ARG_ANYTHING,
-	.arg5_type	= ARG_ANYTHING,
 };

Re: [net-next PATCH 2/9] bpf: sockmap, remove STRPARSER map_flags and add multi-map support

[Alexei Starovoitov]

On Mon, Aug 28, 2017 at 07:10:25AM -0700, John Fastabend wrote:
> The addition of map_flags BPF_SOCKMAP_STRPARSER flags was to handle a
> specific use case where we want to have BPF parse program disabled on
> an entry in a sockmap.
> 
> However, Alexei found the API a bit cumbersome and I agreed. Lets
> remove the STRPARSER flag and support the use case by allowing socks
> to be in multiple maps. This allows users to create two maps one with
> programs attached and one without. When socks are added to maps they
> now inherit any programs attached to the map. This is a nice
> generalization and IMO improves the API.
> 
> The API rules are less ambiguous and do not need a flag:
> 
>   - When a sock is added to a sockmap we have two cases,
> 
>      i. The sock map does not have any attached programs so
>         we can add sock to map without inheriting bpf programs.
>         The sock may exist in 0 or more other maps.
> 
>     ii. The sock map has an attached BPF program. To avoid duplicate
>         bpf programs we only add the sock entry if it does not have
>         an existing strparser/verdict attached, returning -EBUSY if
>         a program is already attached. Otherwise attach the program
>         and inherit strparser/verdict programs from the sock map.
> 
> This allows for socks to be in a multiple maps for redirects and
> inherit a BPF program from a single map.
> 
> Also this patch simplifies the logic around BPF_{EXIST|NOEXIST|ANY}
> flags. In the original patch I tried to be extra clever and only
> update map entries when necessary. Now I've decided the complexity
> is not worth it. If users constantly update an entry with the same
> sock for no reason (i.e. update an entry without actually changing
> any parameters on map or sock) we still do an alloc/release. Using
> this and allowing multiple entries of a sock to exist in a map the
> logic becomes much simpler.
> 
> Note: Now that multiple maps are supported the "maps" pointer called
> when a socket is closed becomes a list of maps to remove the sock from.
> To keep the map up to date when a sock is added to the sockmap we must
> add the map/elem in the list. Likewise when it is removed we must
> remove it from the list. This results in searching the per psock list
> on delete operation. On TCP_CLOSE events we walk the list and remove
> the psock from all map/entry locations. I don't see any perf
> implications in this because at most I have a psock in two maps. If
> a psock were to be in many maps its possibly this might be noticeable
> on delete but I can't think of a reason to dup a psock in many maps.
> The sk_callback_lock is used to protect read/writes to the list. This
> was convenient because in all locations we were taking the lock
> anyways just after working on the list. Also the lock is per sock so
> in normal cases we shouldn't see any contention.
> 
> Suggested-by: Alexei Starovoitov <ast@kernel.org>
> Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support")
> Signed-off-by: John Fastabend <john.fastabend@gmail.com>

nice. I think implementation got cleaner too.
thanks for addresing the comments quickly!
Acked-by: Alexei Starovoitov <ast@kernel.org>

> ---
>  include/uapi/linux/bpf.h |    3 -
>  kernel/bpf/sockmap.c     |  269 ++++++++++++++++++++++++++++------------------
>  2 files changed, 165 insertions(+), 107 deletions(-)
> 
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 97227be..08c206a 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -143,9 +143,6 @@ enum bpf_attach_type {
>  
>  #define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
>  
> -/* If BPF_SOCKMAP_STRPARSER is used sockmap will use strparser on receive */
> -#define BPF_SOCKMAP_STRPARSER	(1U << 0)
> -

Please update tools/include/uapi/linux/bpf.h as well.
Right now it's kinda messed up and still has:
enum bpf_sockmap_flags {
        BPF_SOCKMAP_UNSPEC,
        BPF_SOCKMAP_STRPARSER,
        __MAX_BPF_SOCKMAP_FLAG
};
that's separate patch of course. Not a blocker for this set.

[net-next PATCH 3/9] bpf: sockmap add missing rcu_read_(un)lock in smap_data_ready

[John Fastabend]

References to psock must be done inside RCU critical section.

Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 kernel/bpf/sockmap.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index a6882e5..266011c8 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -227,11 +227,14 @@ static void smap_data_ready(struct sock *sk)
 {
 	struct smap_psock *psock;
 
-	write_lock_bh(&sk->sk_callback_lock);
+	rcu_read_lock();
 	psock = smap_psock_sk(sk);
-	if (likely(psock))
+	if (likely(psock)) {
+		write_lock_bh(&sk->sk_callback_lock);
 		strp_data_ready(&psock->strp);
-	write_unlock_bh(&sk->sk_callback_lock);
+		write_unlock_bh(&sk->sk_callback_lock);
+	}
+	rcu_read_unlock();
 }
 
 static void smap_tx_work(struct work_struct *w)

[net-next PATCH 4/9] bpf: additional sockmap self tests

[John Fastabend]

Add some more sockmap tests to cover,

 - forwarding to NULL entries
 - more than two maps to test list ops
 - forwarding to different map

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 tools/testing/selftests/bpf/sockmap_parse_prog.c   |    6 +
 tools/testing/selftests/bpf/sockmap_verdict_prog.c |   23 +++-
 tools/testing/selftests/bpf/test_maps.c            |  113 +++++++++++++-------
 3 files changed, 96 insertions(+), 46 deletions(-)

diff --git a/tools/testing/selftests/bpf/sockmap_parse_prog.c b/tools/testing/selftests/bpf/sockmap_parse_prog.c
index 710f43f..fae3b96 100644
--- a/tools/testing/selftests/bpf/sockmap_parse_prog.c
+++ b/tools/testing/selftests/bpf/sockmap_parse_prog.c
@@ -19,16 +19,16 @@ int bpf_prog1(struct __sk_buff *skb)
 	void *data = (void *)(long) skb->data;
 	__u32 lport = skb->local_port;
 	__u32 rport = skb->remote_port;
-	char *d = data;
+	__u8 *d = data;
 
-	if (data + 8 > data_end)
+	if (data + 10 > data_end)
 		return skb->len;
 
 	/* This write/read is a bit pointless but tests the verifier and
 	 * strparser handler for read/write pkt data and access into sk
 	 * fields.
 	 */
-	d[0] = 1;
+	d[7] = 1;
 
 	bpf_printk("parse: data[0] = (%u): local_port %i remote %i\n",
 		   d[0], lport, bpf_ntohl(rport));
diff --git a/tools/testing/selftests/bpf/sockmap_verdict_prog.c b/tools/testing/selftests/bpf/sockmap_verdict_prog.c
index 0573c1d..dada207 100644
--- a/tools/testing/selftests/bpf/sockmap_verdict_prog.c
+++ b/tools/testing/selftests/bpf/sockmap_verdict_prog.c
@@ -12,7 +12,14 @@
 				##__VA_ARGS__);			\
 })
 
-struct bpf_map_def SEC("maps") sock_map = {
+struct bpf_map_def SEC("maps") sock_map_rx = {
+	.type = BPF_MAP_TYPE_SOCKMAP,
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.max_entries = 20,
+};
+
+struct bpf_map_def SEC("maps") sock_map_tx = {
 	.type = BPF_MAP_TYPE_SOCKMAP,
 	.key_size = sizeof(int),
 	.value_size = sizeof(int),
@@ -26,11 +33,15 @@ int bpf_prog2(struct __sk_buff *skb)
 	void *data = (void *)(long) skb->data;
 	__u32 lport = skb->local_port;
 	__u32 rport = skb->remote_port;
-	char *d = data;
+	__u8 *d = data;
+	__u8 sk, map;
 
 	if (data + 8 > data_end)
 		return SK_DROP;
 
+	map = d[0];
+	sk = d[1];
+
 	d[0] = 0xd;
 	d[1] = 0xe;
 	d[2] = 0xa;
@@ -40,9 +51,11 @@ int bpf_prog2(struct __sk_buff *skb)
 	d[6] = 0xe;
 	d[7] = 0xf;
 
-	bpf_printk("verdict: data[0] = (%u): local_port %i remote %i redirect 5\n",
-		   d[0], lport, bpf_ntohl(rport));
-	return bpf_sk_redirect_map(&sock_map, 5, 0);
+	bpf_printk("verdict: data[0] = redir(%u:%u)\n", map, sk);
+
+	if (!map)
+		return bpf_sk_redirect_map(&sock_map_rx, sk, 0);
+	return bpf_sk_redirect_map(&sock_map_tx, sk, 0);
 }
 
 char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index 6df6e62..0a7f457 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -465,10 +465,10 @@ static void test_sockmap(int task, void *data)
 {
 	int ports[] = {50200, 50201, 50202, 50204};
 	int err, i, fd, sfd[6] = {0xdeadbeef};
-	char buf[] = "hello sockmap user\n";
-	int one = 1, map_fd, s, sc, rc;
+	u8 buf[20] = {0x0, 0x5, 0x3, 0x2, 0x1, 0x0};
+	int one = 1, map_fd_rx, map_fd_tx, s, sc, rc;
 	int parse_prog, verdict_prog;
-	struct bpf_map *bpf_map;
+	struct bpf_map *bpf_map_rx, *bpf_map_tx;
 	struct sockaddr_in addr;
 	struct bpf_object *obj;
 	struct timeval to;
@@ -585,26 +585,38 @@ static void test_sockmap(int task, void *data)
 		goto out_sockmap;
 	}
 
-	bpf_map = bpf_object__find_map_by_name(obj, "sock_map");
-	if (IS_ERR(bpf_map)) {
-		printf("Failed to load map from verdict prog\n");
+	bpf_map_rx = bpf_object__find_map_by_name(obj, "sock_map_rx");
+	if (IS_ERR(bpf_map_rx)) {
+		printf("Failed to load map rx from verdict prog\n");
 		goto out_sockmap;
 	}
 
-	map_fd = bpf_map__fd(bpf_map);
-	if (map_fd < 0) {
+	map_fd_rx = bpf_map__fd(bpf_map_rx);
+	if (map_fd_rx < 0) {
 		printf("Failed to get map fd\n");
 		goto out_sockmap;
 	}
 
-	err = bpf_prog_attach(parse_prog, map_fd,
+	bpf_map_tx = bpf_object__find_map_by_name(obj, "sock_map_tx");
+	if (IS_ERR(bpf_map_tx)) {
+		printf("Failed to load map tx from verdict prog\n");
+		goto out_sockmap;
+	}
+
+	map_fd_tx = bpf_map__fd(bpf_map_tx);
+	if (map_fd_tx < 0) {
+		printf("Failed to get map tx fd\n");
+		goto out_sockmap;
+	}
+
+	err = bpf_prog_attach(parse_prog, map_fd_rx,
 		      BPF_SK_SKB_STREAM_PARSER, 0);
 	if (err) {
 		printf("Failed bpf prog attach\n");
 		goto out_sockmap;
 	}
 
-	err = bpf_prog_attach(verdict_prog, map_fd,
+	err = bpf_prog_attach(verdict_prog, map_fd_rx,
 			      BPF_SK_SKB_STREAM_VERDICT, 0);
 	if (err) {
 		printf("Failed bpf prog attach\n");
@@ -613,9 +625,15 @@ static void test_sockmap(int task, void *data)
 
 	/* Test map update elem afterwards fd lives in fd and map_fd */
 	for (i = 0; i < 6; i++) {
-		err = bpf_map_update_elem(map_fd, &i, &sfd[i], BPF_ANY);
+		err = bpf_map_update_elem(map_fd_rx, &i, &sfd[i], BPF_ANY);
+		if (err) {
+			printf("Failed map_fd_rx update sockmap %i '%i:%i'\n",
+			       err, i, sfd[i]);
+			goto out_sockmap;
+		}
+		err = bpf_map_update_elem(map_fd_tx, &i, &sfd[i], BPF_ANY);
 		if (err) {
-			printf("Failed map_fd update sockmap %i '%i:%i'\n",
+			printf("Failed map_fd_tx update sockmap %i '%i:%i'\n",
 			       err, i, sfd[i]);
 			goto out_sockmap;
 		}
@@ -623,42 +641,61 @@ static void test_sockmap(int task, void *data)
 
 	/* Test map delete elem and remove send/recv sockets */
 	for (i = 2; i < 4; i++) {
-		err = bpf_map_delete_elem(map_fd, &i);
+		err = bpf_map_delete_elem(map_fd_rx, &i);
+		if (err) {
+			printf("Failed delete sockmap rx %i '%i:%i'\n",
+			       err, i, sfd[i]);
+			goto out_sockmap;
+		}
+		err = bpf_map_delete_elem(map_fd_tx, &i);
 		if (err) {
-			printf("Failed delete  sockmap %i '%i:%i'\n",
+			printf("Failed delete sockmap tx %i '%i:%i'\n",
 			       err, i, sfd[i]);
 			goto out_sockmap;
 		}
 	}
 
 	/* Test map send/recv */
-	sc = send(sfd[2], buf, 10, 0);
-	if (sc < 0) {
-		printf("Failed sockmap send\n");
-		goto out_sockmap;
-	}
+	for (i = 0; i < 2; i++) {
+		buf[0] = i;
+		buf[1] = 0x5;
+		sc = send(sfd[2], buf, 20, 0);
+		if (sc < 0) {
+			printf("Failed sockmap send\n");
+			goto out_sockmap;
+		}
 
-	FD_ZERO(&w);
-	FD_SET(sfd[3], &w);
-	to.tv_sec = 1;
-	to.tv_usec = 0;
-	s = select(sfd[3] + 1, &w, NULL, NULL, &to);
-	if (s == -1) {
-		perror("Failed sockmap select()");
-		goto out_sockmap;
-	} else if (!s) {
-		printf("Failed sockmap unexpected timeout\n");
-		goto out_sockmap;
-	}
+		FD_ZERO(&w);
+		FD_SET(sfd[3], &w);
+		to.tv_sec = 1;
+		to.tv_usec = 0;
+		s = select(sfd[3] + 1, &w, NULL, NULL, &to);
+		if (s == -1) {
+			perror("Failed sockmap select()");
+			goto out_sockmap;
+		} else if (!s) {
+			printf("Failed sockmap unexpected timeout\n");
+			goto out_sockmap;
+		}
 
-	if (!FD_ISSET(sfd[3], &w)) {
-		printf("Failed sockmap select/recv\n");
-		goto out_sockmap;
+		if (!FD_ISSET(sfd[3], &w)) {
+			printf("Failed sockmap select/recv\n");
+			goto out_sockmap;
+		}
+
+		rc = recv(sfd[3], buf, sizeof(buf), 0);
+		if (rc < 0) {
+			printf("Failed sockmap recv\n");
+			goto out_sockmap;
+		}
 	}
 
-	rc = recv(sfd[3], buf, sizeof(buf), 0);
-	if (rc < 0) {
-		printf("Failed sockmap recv\n");
+	/* Negative null entry lookup from datapath should be dropped */
+	buf[0] = 1;
+	buf[1] = 12;
+	sc = send(sfd[2], buf, 20, 0);
+	if (sc < 0) {
+		printf("Failed sockmap send\n");
 		goto out_sockmap;
 	}
 
@@ -730,7 +767,7 @@ static void test_sockmap(int task, void *data)
 	for (i = 0; i < 6; i++)
 		close(sfd[i]);
 	close(fd);
-	close(map_fd);
+	close(map_fd_rx);
 	bpf_object__close(obj);
 	return;
 out:

Re: [net-next PATCH 4/9] bpf: additional sockmap self tests

[Alexei Starovoitov]

On Mon, Aug 28, 2017 at 07:11:05AM -0700, John Fastabend wrote:
> Add some more sockmap tests to cover,
> 
>  - forwarding to NULL entries
>  - more than two maps to test list ops
>  - forwarding to different map
> 
> Signed-off-by: John Fastabend <john.fastabend@gmail.com>

Acked-by: Alexei Starovoitov <ast@kernel.org>

[net-next PATCH 5/9] bpf: more SK_SKB selftests

[John Fastabend]

Tests packet read/writes and additional skb fields.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 tools/testing/selftests/bpf/test_verifier.c |   98 +++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 353d170..8eb0995 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -1119,6 +1119,104 @@ struct test_val {
 		.prog_type = BPF_PROG_TYPE_SK_SKB,
 	},
 	{
+		"invalid access of tc_classid for SK_SKB",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+				    offsetof(struct __sk_buff, tc_classid)),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_SK_SKB,
+		.errstr = "invalid bpf_context access",
+	},
+	{
+		"check skb->mark is writeable by SK_SKB",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+				    offsetof(struct __sk_buff, mark)),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_SK_SKB,
+	},
+	{
+		"check skb->tc_index is writeable by SK_SKB",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+				    offsetof(struct __sk_buff, tc_index)),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_SK_SKB,
+	},
+	{
+		"check skb->priority is writeable by SK_SKB",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+				    offsetof(struct __sk_buff, priority)),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_SK_SKB,
+	},
+	{
+		"direct packet read for SK_SKB",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct __sk_buff, data)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct __sk_buff, data_end)),
+			BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
+			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_2, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_SK_SKB,
+	},
+	{
+		"direct packet write for SK_SKB",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct __sk_buff, data)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct __sk_buff, data_end)),
+			BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
+			BPF_STX_MEM(BPF_B, BPF_REG_2, BPF_REG_2, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_SK_SKB,
+	},
+	{
+		"overlapping checks for direct packet access SK_SKB",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct __sk_buff, data)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct __sk_buff, data_end)),
+			BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 4),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 6),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 1),
+			BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_2, 6),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_SK_SKB,
+	},
+	{
 		"check skb->mark is not writeable by sockets",
 		.insns = {
 			BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_1,

Re: [net-next PATCH 5/9] bpf: more SK_SKB selftests

[Alexei Starovoitov]

On Mon, Aug 28, 2017 at 07:11:24AM -0700, John Fastabend wrote:
> Tests packet read/writes and additional skb fields.
> 
> Signed-off-by: John Fastabend <john.fastabend@gmail.com>

Acked-by: Alexei Starovoitov <ast@kernel.org>

>  	{
> +		"invalid access of tc_classid for SK_SKB",
> +		.insns = {
> +			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
> +				    offsetof(struct __sk_buff, tc_classid)),
> +			BPF_EXIT_INSN(),
> +		},
> +		.result = REJECT,
> +		.prog_type = BPF_PROG_TYPE_SK_SKB,
> +		.errstr = "invalid bpf_context access",

it shouldn't be readable eight, right?

[net-next PATCH 6/9] bpf: harden sockmap program attach to ensure correct map type

[John Fastabend]

When attaching a program to sockmap we need to check map type
is correct.

Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 kernel/bpf/sockmap.c                               |    3 ++
 tools/testing/selftests/bpf/sockmap_verdict_prog.c |    7 +++++
 tools/testing/selftests/bpf/test_maps.c            |   27 +++++++++++++++++---
 3 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 266011c8..38bf4e4 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -794,6 +794,9 @@ int sock_map_attach_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type)
 	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
 	struct bpf_prog *orig;
 
+	if (unlikely(map->map_type != BPF_MAP_TYPE_SOCKMAP))
+		return -EINVAL;
+
 	switch (type) {
 	case BPF_SK_SKB_STREAM_PARSER:
 		orig = xchg(&stab->bpf_parse, prog);
diff --git a/tools/testing/selftests/bpf/sockmap_verdict_prog.c b/tools/testing/selftests/bpf/sockmap_verdict_prog.c
index dada207..9b99bd1 100644
--- a/tools/testing/selftests/bpf/sockmap_verdict_prog.c
+++ b/tools/testing/selftests/bpf/sockmap_verdict_prog.c
@@ -26,6 +26,13 @@ struct bpf_map_def SEC("maps") sock_map_tx = {
 	.max_entries = 20,
 };
 
+struct bpf_map_def SEC("maps") sock_map_break = {
+	.type = BPF_MAP_TYPE_ARRAY,
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.max_entries = 20,
+};
+
 SEC("sk_skb2")
 int bpf_prog2(struct __sk_buff *skb)
 {
diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index 0a7f457..0c4b56d 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -463,12 +463,12 @@ static void test_devmap(int task, void *data)
 #define SOCKMAP_VERDICT_PROG "./sockmap_verdict_prog.o"
 static void test_sockmap(int task, void *data)
 {
+	int one = 1, map_fd_rx, map_fd_tx, map_fd_break, s, sc, rc;
+	struct bpf_map *bpf_map_rx, *bpf_map_tx, *bpf_map_break;
 	int ports[] = {50200, 50201, 50202, 50204};
 	int err, i, fd, sfd[6] = {0xdeadbeef};
 	u8 buf[20] = {0x0, 0x5, 0x3, 0x2, 0x1, 0x0};
-	int one = 1, map_fd_rx, map_fd_tx, s, sc, rc;
 	int parse_prog, verdict_prog;
-	struct bpf_map *bpf_map_rx, *bpf_map_tx;
 	struct sockaddr_in addr;
 	struct bpf_object *obj;
 	struct timeval to;
@@ -609,17 +609,36 @@ static void test_sockmap(int task, void *data)
 		goto out_sockmap;
 	}
 
+	bpf_map_break = bpf_object__find_map_by_name(obj, "sock_map_break");
+	if (IS_ERR(bpf_map_break)) {
+		printf("Failed to load map tx from verdict prog\n");
+		goto out_sockmap;
+	}
+
+	map_fd_break = bpf_map__fd(bpf_map_break);
+	if (map_fd_break < 0) {
+		printf("Failed to get map tx fd\n");
+		goto out_sockmap;
+	}
+
+	err = bpf_prog_attach(parse_prog, map_fd_break,
+			      BPF_SK_SKB_STREAM_PARSER, 0);
+	if (!err) {
+		printf("Allowed attaching SK_SKB program to invalid map\n");
+		goto out_sockmap;
+	}
+
 	err = bpf_prog_attach(parse_prog, map_fd_rx,
 		      BPF_SK_SKB_STREAM_PARSER, 0);
 	if (err) {
-		printf("Failed bpf prog attach\n");
+		printf("Failed stream parser bpf prog attach\n");
 		goto out_sockmap;
 	}
 
 	err = bpf_prog_attach(verdict_prog, map_fd_rx,
 			      BPF_SK_SKB_STREAM_VERDICT, 0);
 	if (err) {
-		printf("Failed bpf prog attach\n");
+		printf("Failed stream verdict bpf prog attach\n");
 		goto out_sockmap;
 	}
 

Re: [net-next PATCH 6/9] bpf: harden sockmap program attach to ensure correct map type

[Alexei Starovoitov]

On Mon, Aug 28, 2017 at 07:11:43AM -0700, John Fastabend wrote:
> When attaching a program to sockmap we need to check map type
> is correct.
> 
> Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support")
> Signed-off-by: John Fastabend <john.fastabend@gmail.com>

good catch. Great to see that you're adding a test for it too.

Acked-by: Alexei Starovoitov <ast@kernel.org>

[net-next PATCH 7/9] bpf: sockmap indicate sock events to listeners

[John Fastabend]

After userspace pushes sockets into a sockmap it may not be receiving
data (assuming stream_{parser|verdict} programs are attached). But, it
may still want to manage the socks. A common pattern is to poll/select
for a POLLRDHUP event so we can close the sock.

This patch adds the logic to wake up these listeners.

Also add TCP_SYN_SENT to the list of events to handle. We don't want
to break the connection just because we happen to be in this state.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 kernel/bpf/sockmap.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 38bf4e4..bcc326a 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -162,6 +162,7 @@ static void smap_state_change(struct sock *sk)
 {
 	struct smap_psock_map_entry *e, *tmp;
 	struct smap_psock *psock;
+	struct socket_wq *wq;
 	struct sock *osk;
 
 	rcu_read_lock();
@@ -171,6 +172,7 @@ static void smap_state_change(struct sock *sk)
 	 * is established.
 	 */
 	switch (sk->sk_state) {
+	case TCP_SYN_SENT:
 	case TCP_SYN_RECV:
 	case TCP_ESTABLISHED:
 		break;
@@ -208,6 +210,10 @@ static void smap_state_change(struct sock *sk)
 		smap_report_sk_error(psock, EPIPE);
 		break;
 	}
+
+	wq = rcu_dereference(sk->sk_wq);
+	if (skwq_has_sleeper(wq))
+		wake_up_interruptible_all(&wq->wait);
 	rcu_read_unlock();
 }
 

[net-next PATCH 8/9] bpf: sockmap requires STREAM_PARSER add Kconfig entry

[John Fastabend]

SOCKMAP uses strparser code (compiled with Kconfig option
CONFIG_STREAM_PARSER) to run the parser BPF program. Without this
config option set sockmap wont be compiled. However, at the moment
the only way to pull in the strparser code is to enable KCM.

To resolve this create a BPF specific config option to pull
only the strparser piece in that sockmap needs. This also
allows folks who want to use BPF/syscall/maps but don't need
sockmap to easily opt out.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 net/Kconfig |   12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/net/Kconfig b/net/Kconfig
index 7d57ef3..17ca213 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -301,6 +301,18 @@ config BPF_JIT
 	  /proc/sys/net/core/bpf_jit_harden   (optional)
 	  /proc/sys/net/core/bpf_jit_kallsyms (optional)
 
+config BPF_STREAM_PARSER
+	bool "enable BPF STREAM_PARSER"
+	depends on BPF_SYSCALL
+	select STREAM_PARSER
+	---help---
+	 Enabling this allows a stream parser to be used with
+	 BPF_MAP_TYPE_SOCKMAP.
+
+	 BPF_MAP_TYPE_SOCKMAP provides a map type to use with network sockets.
+	 It can be used to enforce socket policy, implement socket redirects,
+	 etc.
+
 config NET_FLOW_LIMIT
 	bool
 	depends on RPS

Re: [net-next PATCH 8/9] bpf: sockmap requires STREAM_PARSER add Kconfig entry

[Alexei Starovoitov]

On Mon, Aug 28, 2017 at 07:12:21AM -0700, John Fastabend wrote:
> SOCKMAP uses strparser code (compiled with Kconfig option
> CONFIG_STREAM_PARSER) to run the parser BPF program. Without this
> config option set sockmap wont be compiled. However, at the moment
> the only way to pull in the strparser code is to enable KCM.
> 
> To resolve this create a BPF specific config option to pull
> only the strparser piece in that sockmap needs. This also
> allows folks who want to use BPF/syscall/maps but don't need
> sockmap to easily opt out.
> 
> Signed-off-by: John Fastabend <john.fastabend@gmail.com>

Acked-by: Alexei Starovoitov <ast@kernel.org>

[net-next PATCH 9/9] bpf: test_maps add sockmap stress test

[John Fastabend]

Sockmap is a bit different than normal stress tests that can run
in parallel as is. We need to reuse the same socket pool and map
pool to get good stress test cases.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 tools/testing/selftests/bpf/test_maps.c |   29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index 0c4b56d..7059bb3 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -461,7 +461,7 @@ static void test_devmap(int task, void *data)
 #include <linux/err.h>
 #define SOCKMAP_PARSE_PROG "./sockmap_parse_prog.o"
 #define SOCKMAP_VERDICT_PROG "./sockmap_verdict_prog.o"
-static void test_sockmap(int task, void *data)
+static void test_sockmap(int tasks, void *data)
 {
 	int one = 1, map_fd_rx, map_fd_tx, map_fd_break, s, sc, rc;
 	struct bpf_map *bpf_map_rx, *bpf_map_tx, *bpf_map_break;
@@ -473,6 +473,7 @@ static void test_sockmap(int task, void *data)
 	struct bpf_object *obj;
 	struct timeval to;
 	__u32 key, value;
+	pid_t pid[tasks];
 	fd_set w;
 
 	/* Create some sockets to use with sockmap */
@@ -782,6 +783,32 @@ static void test_sockmap(int task, void *data)
 		}
 	}
 
+	/* Test tasks number of forked operations */
+	for (i = 0; i < tasks; i++) {
+		pid[i] = fork();
+		if (pid[i] == 0) {
+			for (i = 0; i < 6; i++) {
+				bpf_map_delete_elem(map_fd_tx, &i);
+				bpf_map_delete_elem(map_fd_rx, &i);
+				bpf_map_update_elem(map_fd_tx, &i,
+						    &sfd[i], BPF_ANY);
+				bpf_map_update_elem(map_fd_rx, &i,
+						    &sfd[i], BPF_ANY);
+			}
+			exit(0);
+		} else if (pid[i] == -1) {
+			printf("Couldn't spawn #%d process!\n", i);
+			exit(1);
+		}
+	}
+
+	for (i = 0; i < tasks; i++) {
+		int status;
+
+		assert(waitpid(pid[i], &status, 0) == pid[i]);
+		assert(status == 0);
+	}
+
 	/* Test map close sockets */
 	for (i = 0; i < 6; i++)
 		close(sfd[i]);

Re: [net-next PATCH 0/9] sockmap UAPI updates and fixes

[David Miller]

From: John Fastabend <john.fastabend@gmail.com>
Date: Mon, 28 Aug 2017 07:09:45 -0700

> This series updates sockmap UAPI, adds additional test cases and
> provides a couple fixes.
> 
> First the UAPI changes. The original API added two sockmap specific
> API artifacts (a) a new map_flags field with a sockmap specific update
> command and (b) a new sockmap specific attach field in the attach data
> structure. After this series instead of attaching programs with a
> single command now two commands are used to attach programs to maps
> individually. This allows us to add new programs easily in the future
> and avoids any specific sockmap data structure additions. The
> map_flags field is also removed and instead we allow socks to be
> added to multiple maps that may or may not have programs attached.
> This allows users to decide if a sock should run a SK_SKB program type
> on receive based on the map it is attached to. This is a nice
> improvement. See patches for specific details.
> 
> More test cases were added to test above changes and also stress test
> the interface.
> 
> Finally two fixes/improvements were made. First a missing rcu
> section was added. Second now sockmap can build without KCM being
> used to trigger 'y' on CONFIG_STREAM_PARSER by selecting a new
> BPF config option.

Series applied, thanks John.