[PATCH v2] linux-user: Add most IFTUN ioctls

[Shu-Chun Weng <scw@google.com>]

The three options handling `struct sock_fprog` (TUNATTACHFILTER,
TUNDETACHFILTER, and TUNGETFILTER) are not implemented. Linux kernel
keeps a user space pointer in them which we cannot correctly handle.

Signed-off-by: Josh Kunz <jkz@google.com>
Signed-off-by: Shu-Chun Weng <scw@google.com>
---
v2:
  Title changed from "linux-user: Add several IFTUN ioctls"

  Properly specify the argument types for various options, including a custom
  implementation for TUNSETTXFILTER.

  #ifdef guards for macros introduced up to 5 years ago.

 linux-user/ioctls.h       | 45 +++++++++++++++++++++++++++++++++++++++
 linux-user/syscall.c      | 36 +++++++++++++++++++++++++++++++
 linux-user/syscall_defs.h | 32 ++++++++++++++++++++++++++++
 3 files changed, 113 insertions(+)

diff --git a/linux-user/ioctls.h b/linux-user/ioctls.h
index 0713ae1311..b9fb01f558 100644
--- a/linux-user/ioctls.h
+++ b/linux-user/ioctls.h
@@ -593,3 +593,48 @@
   IOCTL(KCOV_DISABLE, 0, TYPE_NULL)
   IOCTL(KCOV_INIT_TRACE, IOC_R, TYPE_ULONG)
 #endif
+
+  IOCTL(TUNSETDEBUG,     IOC_W, TYPE_INT)
+  IOCTL(TUNSETIFF,       IOC_RW, MK_PTR(MK_STRUCT(STRUCT_short_ifreq)))
+  IOCTL(TUNSETPERSIST,   IOC_W, TYPE_INT)
+  IOCTL(TUNSETOWNER,     IOC_W, TYPE_INT)
+  IOCTL(TUNSETLINK,      IOC_W, TYPE_INT)
+  IOCTL(TUNSETGROUP,     IOC_W, TYPE_INT)
+  IOCTL(TUNGETFEATURES,  IOC_R, MK_PTR(TYPE_INT))
+  IOCTL(TUNSETOFFLOAD,   IOC_W, TYPE_LONG)
+  IOCTL_SPECIAL(TUNSETTXFILTER, IOC_W, do_ioctl_TUNSETTXFILTER,
+                /*
+                 * We can't represent `struct tun_filter` in thunk so leaving
+                 * this empty. do_ioctl_TUNSETTXFILTER will do the conversion.
+                 */
+                TYPE_NULL)
+  IOCTL(TUNGETIFF,       IOC_R, MK_PTR(MK_STRUCT(STRUCT_short_ifreq)))
+  IOCTL(TUNGETSNDBUF,    IOC_R, MK_PTR(TYPE_INT))
+  IOCTL(TUNSETSNDBUF,    IOC_W, MK_PTR(TYPE_INT))
+  /*
+   * TUNATTACHFILTER and TUNDETACHFILTER are not supported. Linux kernel keeps a
+   * user pointer in TUNATTACHFILTER, which we are not able to correctly handle.
+   */
+  IOCTL(TUNGETVNETHDRSZ, IOC_R, MK_PTR(TYPE_INT))
+  IOCTL(TUNSETVNETHDRSZ, IOC_W, MK_PTR(TYPE_INT))
+  IOCTL(TUNSETQUEUE,     IOC_W, MK_PTR(MK_STRUCT(STRUCT_short_ifreq)))
+  IOCTL(TUNSETIFINDEX ,  IOC_W, MK_PTR(TYPE_INT))
+  /* TUNGETFILTER is not supported: see TUNATTACHFILTER. */
+  IOCTL(TUNSETVNETLE,    IOC_W, MK_PTR(TYPE_INT))
+  IOCTL(TUNGETVNETLE,    IOC_R, MK_PTR(TYPE_INT))
+#ifdef TUNSETVNETBE
+  IOCTL(TUNSETVNETBE,    IOC_W, MK_PTR(TYPE_INT))
+  IOCTL(TUNGETVNETBE,    IOC_R, MK_PTR(TYPE_INT))
+#endif
+#ifdef TUNSETSTEERINGEBPF
+  IOCTL(TUNSETSTEERINGEBPF, IOC_W, MK_PTR(TYPE_INT))
+#endif
+#ifdef TUNSETFILTEREBPF
+  IOCTL(TUNSETFILTEREBPF, IOC_W, MK_PTR(TYPE_INT))
+#endif
+#ifdef TUNSETCARRIER
+  IOCTL(TUNSETCARRIER,   IOC_W, MK_PTR(TYPE_INT))
+#endif
+#ifdef TUNGETDEVNETNS
+  IOCTL(TUNGETDEVNETNS,  IOC_R, TYPE_NULL)
+#endif
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 1211e759c2..7f1efed189 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -56,6 +56,7 @@
 #include <linux/wireless.h>
 #include <linux/icmp.h>
 #include <linux/icmpv6.h>
+#include <linux/if_tun.h>
 #include <linux/errqueue.h>
 #include <linux/random.h>
 #ifdef CONFIG_TIMERFD
@@ -5422,6 +5423,41 @@ static abi_long do_ioctl_drm(const IOCTLEntry *ie, uint8_t *buf_temp,
 
 #endif
 
+static abi_long do_ioctl_TUNSETTXFILTER(const IOCTLEntry *ie, uint8_t *buf_temp,
+                                        int fd, int cmd, abi_long arg)
+{
+    struct tun_filter *filter = (struct tun_filter *)buf_temp;
+    struct tun_filter *target_filter;
+    char *target_addr;
+
+    assert(ie->access == IOC_W);
+
+    target_filter = lock_user(VERIFY_READ, arg, sizeof(*filter), 1);
+    if (!target_filter) {
+        return -TARGET_EFAULT;
+    }
+    filter->flags = tswap16(target_filter->flags);
+    filter->count = tswap16(target_filter->count);
+    unlock_user(target_filter, arg, sizeof(*filter));
+
+    if (filter->count) {
+        if (sizeof(*filter) + filter->count * ETH_ALEN > MAX_STRUCT_SIZE) {
+            return -TARGET_EFAULT;
+        }
+
+        target_addr = lock_user(VERIFY_READ, arg + sizeof(*filter),
+                                filter->count * ETH_ALEN, 1);
+        if (!target_addr) {
+            return -TARGET_EFAULT;
+        }
+        memcpy(filter->addr, target_addr, filter->count * ETH_ALEN);
+        unlock_user(target_addr, arg + sizeof(*filter),
+                    filter->count * ETH_ALEN);
+    }
+
+    return get_errno(safe_ioctl(fd, ie->host_cmd, filter));
+}
+
 IOCTLEntry ioctl_entries[] = {
 #define IOCTL(cmd, access, ...) \
     { TARGET_ ## cmd, cmd, #cmd, access, 0, {  __VA_ARGS__ } },
diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
index 3c261cff0e..7ef0ff0328 100644
--- a/linux-user/syscall_defs.h
+++ b/linux-user/syscall_defs.h
@@ -891,6 +891,38 @@ struct target_rtc_pll_info {
 
 #define TARGET_SIOCGIWNAME     0x8B01          /* get name == wireless protocol */
 
+/* From <linux/if_tun.h> */
+
+#define TARGET_TUNSETDEBUG        TARGET_IOW('T', 201, int)
+#define TARGET_TUNSETIFF          TARGET_IOW('T', 202, int)
+#define TARGET_TUNSETPERSIST      TARGET_IOW('T', 203, int)
+#define TARGET_TUNSETOWNER        TARGET_IOW('T', 204, int)
+#define TARGET_TUNSETLINK         TARGET_IOW('T', 205, int)
+#define TARGET_TUNSETGROUP        TARGET_IOW('T', 206, int)
+#define TARGET_TUNGETFEATURES     TARGET_IOR('T', 207, unsigned int)
+#define TARGET_TUNSETOFFLOAD      TARGET_IOW('T', 208, unsigned int)
+#define TARGET_TUNSETTXFILTER     TARGET_IOW('T', 209, unsigned int)
+#define TARGET_TUNGETIFF          TARGET_IOR('T', 210, unsigned int)
+#define TARGET_TUNGETSNDBUF       TARGET_IOR('T', 211, int)
+#define TARGET_TUNSETSNDBUF       TARGET_IOW('T', 212, int)
+/*
+ * TUNATTACHFILTER and TUNDETACHFILTER are not supported. Linux kernel keeps a
+ * user pointer in TUNATTACHFILTER, which we are not able to correctly handle.
+ */
+#define TARGET_TUNGETVNETHDRSZ    TARGET_IOR('T', 215, int)
+#define TARGET_TUNSETVNETHDRSZ    TARGET_IOW('T', 216, int)
+#define TARGET_TUNSETQUEUE        TARGET_IOW('T', 217, int)
+#define TARGET_TUNSETIFINDEX      TARGET_IOW('T', 218, unsigned int)
+/* TUNGETFILTER is not supported: see TUNATTACHFILTER. */
+#define TARGET_TUNSETVNETLE       TARGET_IOW('T', 220, int)
+#define TARGET_TUNGETVNETLE       TARGET_IOR('T', 221, int)
+#define TARGET_TUNSETVNETBE       TARGET_IOW('T', 222, int)
+#define TARGET_TUNGETVNETBE       TARGET_IOR('T', 223, int)
+#define TARGET_TUNSETSTEERINGEBPF TARGET_IOR('T', 224, int)
+#define TARGET_TUNSETFILTEREBPF   TARGET_IOR('T', 225, int)
+#define TARGET_TUNSETCARRIER      TARGET_IOW('T', 226, int)
+#define TARGET_TUNGETDEVNETNS     TARGET_IO('T', 227)
+
 /* From <linux/random.h> */
 
 #define TARGET_RNDGETENTCNT    TARGET_IOR('R', 0x00, int)
-- 
2.28.0.rc0.142.g3c755180ce-goog