[PATCH v2 bpf-next 06/17] bpf: net: Change do_ip_getsockopt() to take the sockptr_t argument

Martin KaFai Lau
2022-09-02T00:31:04Z

Similar to the earlier patch that changes sk_getsockopt() to
take the sockptr_t argument. This patch also changes
do_ip_getsockopt() to take the sockptr_t argument such that
a latter patch can make bpf_getsockopt(SOL_IP) to reuse
do_ip_getsockopt().

Note on the change in ip_mc_gsfget(). This function is to
return an array of sockaddr_storage in optval. This function
is shared between ip_get_mcast_msfilter() and
compat_ip_get_mcast_msfilter(). However, the sockaddr_storage
is stored at different offset of the optval because of
the difference between group_filter and compat_group_filter.
Thus, a new 'ss_offset' argument is added to ip_mc_gsfget().

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
---
include/linux/igmp.h | 4 +--
include/linux/mroute.h | 6 ++--
net/ipv4/igmp.c | 22 +++++++-----
net/ipv4/ip_sockglue.c | 80 ++++++++++++++++++++++++------------------
net/ipv4/ipmr.c | 9 ++---
5 files changed, 68 insertions(+), 53 deletions(-)

diff --git a/include/linux/igmp.h b/include/linux/igmp.h
index 93c262ecbdc9..78890143f079 100644
--- a/include/linux/igmp.h
+++ b/include/linux/igmp.h
@@ -118,9 +118,9 @@ extern int ip_mc_source(int add, int omode, struct sock *sk,
struct ip_mreq_source *mreqs, int ifindex);
extern int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf,int ifindex);
extern int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
- struct ip_msfilter __user *optval, int __user *optlen);
+ sockptr_t optval, sockptr_t optlen);
extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
- struct sockaddr_storage __user *p);
+ sockptr_t optval, size_t offset);
extern int ip_mc_sf_allow(struct sock *sk, __be32 local, __be32 rmt,
int dif, int sdif);
extern void ip_mc_init_dev(struct in_device *);
diff --git a/include/linux/mroute.h b/include/linux/mroute.h
index 6cbbfe94348c..80b8400ab8b2 100644
--- a/include/linux/mroute.h
+++ b/include/linux/mroute.h
@@ -17,7 +17,7 @@ static inline int ip_mroute_opt(int opt)
}

int ip_mroute_setsockopt(struct sock *, int, sockptr_t, unsigned int);
-int ip_mroute_getsockopt(struct sock *, int, char __user *, int __user *);
+int ip_mroute_getsockopt(struct sock *, int, sockptr_t, sockptr_t);
int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg);
int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
int ip_mr_init(void);
@@ -29,8 +29,8 @@ static inline int ip_mroute_setsockopt(struct sock *sock, int optname,
return -ENOPROTOOPT;
}

-static inline int ip_mroute_getsockopt(struct sock *sock, int optname,
- char __user *optval, int __user *optlen)
+static inline int ip_mroute_getsockopt(struct sock *sk, int optname,
+ sockptr_t optval, sockptr_t optlen)
{
return -ENOPROTOOPT;
}
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index e3ab0cb61624..df0660d818ac 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -2529,11 +2529,10 @@ int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
err = ip_mc_leave_group(sk, &imr);
return err;
}
-
int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
- struct ip_msfilter __user *optval, int __user *optlen)
+ sockptr_t optval, sockptr_t optlen)
{
- int err, len, count, copycount;
+ int err, len, count, copycount, msf_size;
struct ip_mreqn imr;
__be32 addr = msf->imsf_multiaddr;
struct ip_mc_socklist *pmc;
@@ -2575,12 +2574,15 @@ int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
len = flex_array_size(psl, sl_addr, copycount);
msf->imsf_numsrc = count;
- if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
- copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
+ msf_size = IP_MSFILTER_SIZE(copycount);
+ if (copy_to_sockptr(optlen, &msf_size, sizeof(int)) ||
+ copy_to_sockptr(optval, msf, IP_MSFILTER_SIZE(0))) {
return -EFAULT;
}
if (len &&
- copy_to_user(&optval->imsf_slist_flex[0], psl->sl_addr, len))
+ copy_to_sockptr_offset(optval,
+ offsetof(struct ip_msfilter, imsf_slist_flex),
+ psl->sl_addr, len))
return -EFAULT;
return 0;
done:
@@ -2588,7 +2590,7 @@ int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
}

int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
- struct sockaddr_storage __user *p)
+ sockptr_t optval, size_t ss_offset)
{
int i, count, copycount;
struct sockaddr_in *psin;
@@ -2618,15 +2620,17 @@ int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
count = psl ? psl->sl_count : 0;
copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
gsf->gf_numsrc = count;
- for (i = 0; i < copycount; i++, p++) {
+ for (i = 0; i < copycount; i++) {
struct sockaddr_storage ss;

psin = (struct sockaddr_in *)&ss;
memset(&ss, 0, sizeof(ss));
psin->sin_family = AF_INET;
psin->sin_addr.s_addr = psl->sl_addr[i];
- if (copy_to_user(p, &ss, sizeof(ss)))
+ if (copy_to_sockptr_offset(optval, ss_offset,
+ &ss, sizeof(ss)))
return -EFAULT;
+ ss_offset += sizeof(ss);
}
return 0;
}
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 751fa69cb557..5310def20e0c 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1462,37 +1462,37 @@ static bool getsockopt_needs_rtnl(int optname)
return false;
}

-static int ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
- int __user *optlen, int len)
+static int ip_get_mcast_msfilter(struct sock *sk, sockptr_t optval,
+ sockptr_t optlen, int len)
{
const int size0 = offsetof(struct group_filter, gf_slist_flex);
- struct group_filter __user *p = optval;
struct group_filter gsf;
- int num;
+ int num, gsf_size;
int err;

if (len < size0)
return -EINVAL;
- if (copy_from_user(&gsf, p, size0))
+ if (copy_from_sockptr(&gsf, optval, size0))
return -EFAULT;

num = gsf.gf_numsrc;
- err = ip_mc_gsfget(sk, &gsf, p->gf_slist_flex);
+ err = ip_mc_gsfget(sk, &gsf, optval,
+ offsetof(struct group_filter, gf_slist_flex));
if (err)
return err;
if (gsf.gf_numsrc < num)
num = gsf.gf_numsrc;
- if (put_user(GROUP_FILTER_SIZE(num), optlen) ||
- copy_to_user(p, &gsf, size0))
+ gsf_size = GROUP_FILTER_SIZE(num);
+ if (copy_to_sockptr(optlen, &gsf_size, sizeof(int)) ||
+ copy_to_sockptr(optval, &gsf, size0))
return -EFAULT;
return 0;
}

-static int compat_ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
- int __user *optlen, int len)
+static int compat_ip_get_mcast_msfilter(struct sock *sk, sockptr_t optval,
+ sockptr_t optlen, int len)
{
const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
- struct compat_group_filter __user *p = optval;
struct compat_group_filter gf32;
struct group_filter gf;
int num;
@@ -1500,7 +1500,7 @@ static int compat_ip_get_mcast_msfilter(struct sock *sk, void __user *optval,

if (len < size0)
return -EINVAL;
- if (copy_from_user(&gf32, p, size0))
+ if (copy_from_sockptr(&gf32, optval, size0))
return -EFAULT;

gf.gf_interface = gf32.gf_interface;
@@ -1508,21 +1508,24 @@ static int compat_ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
num = gf.gf_numsrc = gf32.gf_numsrc;
gf.gf_group = gf32.gf_group;

- err = ip_mc_gsfget(sk, &gf, p->gf_slist_flex);
+ err = ip_mc_gsfget(sk, &gf, optval,
+ offsetof(struct compat_group_filter, gf_slist_flex));
if (err)
return err;
if (gf.gf_numsrc < num)
num = gf.gf_numsrc;
len = GROUP_FILTER_SIZE(num) - (sizeof(gf) - sizeof(gf32));
- if (put_user(len, optlen) ||
- put_user(gf.gf_fmode, &p->gf_fmode) ||
- put_user(gf.gf_numsrc, &p->gf_numsrc))
+ if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
+ copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_fmode),
+ &gf.gf_fmode, sizeof(gf.gf_fmode)) ||
+ copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_numsrc),
+ &gf.gf_numsrc, sizeof(gf.gf_numsrc)))
return -EFAULT;
return 0;
}

static int do_ip_getsockopt(struct sock *sk, int level, int optname,
- char __user *optval, int __user *optlen)
+ sockptr_t optval, sockptr_t optlen)
{
struct inet_sock *inet = inet_sk(sk);
bool needs_rtnl = getsockopt_needs_rtnl(optname);
@@ -1535,7 +1538,7 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
if (ip_mroute_opt(optname))
return ip_mroute_getsockopt(sk, optname, optval, optlen);

- if (get_user(len, optlen))
+ if (copy_from_sockptr(&len, optlen, sizeof(int)))
return -EFAULT;
if (len < 0)
return -EINVAL;
@@ -1560,15 +1563,17 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
inet_opt->opt.optlen);
release_sock(sk);

- if (opt->optlen == 0)
- return put_user(0, optlen);
+ if (opt->optlen == 0) {
+ len = 0;
+ return copy_to_sockptr(optlen, &len, sizeof(int));
+ }

ip_options_undo(opt);

len = min_t(unsigned int, len, opt->optlen);
- if (put_user(len, optlen))
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
return -EFAULT;
- if (copy_to_user(optval, opt->__data, len))
+ if (copy_to_sockptr(optval, opt->__data, len))
return -EFAULT;
return 0;
}
@@ -1659,9 +1664,9 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
addr.s_addr = inet->mc_addr;
release_sock(sk);

- if (put_user(len, optlen))
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
return -EFAULT;
- if (copy_to_user(optval, &addr, len))
+ if (copy_to_sockptr(optval, &addr, len))
return -EFAULT;
return 0;
}
@@ -1673,12 +1678,11 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
err = -EINVAL;
goto out;
}
- if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
+ if (copy_from_sockptr(&msf, optval, IP_MSFILTER_SIZE(0))) {
err = -EFAULT;
goto out;
}
- err = ip_mc_msfget(sk, &msf,
- (struct ip_msfilter __user *)optval, optlen);
+ err = ip_mc_msfget(sk, &msf, optval, optlen);
goto out;
}
case MCAST_MSFILTER:
@@ -1700,8 +1704,13 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
if (sk->sk_type != SOCK_STREAM)
return -ENOPROTOOPT;

- msg.msg_control_is_user = true;
- msg.msg_control_user = optval;
+ if (optval.is_kernel) {
+ msg.msg_control_is_user = false;
+ msg.msg_control = optval.kernel;
+ } else {
+ msg.msg_control_is_user = true;
+ msg.msg_control_user = optval.user;
+ }
msg.msg_controllen = len;
msg.msg_flags = in_compat_syscall() ? MSG_CMSG_COMPAT : 0;

@@ -1722,7 +1731,7 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
}
len -= msg.msg_controllen;
- return put_user(len, optlen);
+ return copy_to_sockptr(optlen, &len, sizeof(int));
}
case IP_FREEBIND:
val = inet->freebind;
@@ -1742,15 +1751,15 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
unsigned char ucval = (unsigned char)val;
len = 1;
- if (put_user(len, optlen))
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
return -EFAULT;
- if (copy_to_user(optval, &ucval, 1))
+ if (copy_to_sockptr(optval, &ucval, 1))
return -EFAULT;
} else {
len = min_t(unsigned int, sizeof(int), len);
- if (put_user(len, optlen))
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
return -EFAULT;
- if (copy_to_user(optval, &val, len))
+ if (copy_to_sockptr(optval, &val, len))
return -EFAULT;
}
return 0;
@@ -1767,7 +1776,8 @@ int ip_getsockopt(struct sock *sk, int level,
{
int err;

- err = do_ip_getsockopt(sk, level, optname, optval, optlen);
+ err = do_ip_getsockopt(sk, level, optname,
+ USER_SOCKPTR(optval), USER_SOCKPTR(optlen));

#if IS_ENABLED(CONFIG_BPFILTER_UMH)
if (optname >= BPFILTER_IPT_SO_GET_INFO &&
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 73651d17e51f..95eefbe2e142 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1546,7 +1546,8 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, sockptr_t optval,
}

/* Getsock opt support for the multicast routing system. */
-int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
+int ip_mroute_getsockopt(struct sock *sk, int optname, sockptr_t optval,
+ sockptr_t optlen)
{
int olr;
int val;
@@ -1577,14 +1578,14 @@ int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int
return -ENOPROTOOPT;
}

- if (get_user(olr, optlen))
+ if (copy_from_sockptr(&olr, optlen, sizeof(int)))
return -EFAULT;
olr = min_t(unsigned int, olr, sizeof(int));
if (olr < 0)
return -EINVAL;
- if (put_user(olr, optlen))
+ if (copy_to_sockptr(optlen, &olr, sizeof(int)))
return -EFAULT;
- if (copy_to_user(optval, &val, olr))
+ if (copy_to_sockptr(optval, &val, olr))
return -EFAULT;
return 0;
}
--
2.30.2