From: Al Viro <v...@zeniv.linux.org.uk>

pass the userland pointer to the array in its tail, so that part
gets copied out by our functions; copyout of everything else is
done in the callers.  Rationale: reuse for compat; the array
is the same in native and compat, the layout of parts before it
is different for compat.

Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
---
 include/linux/igmp.h     |  2 +-
 include/net/ipv6.h       |  2 +-
 net/ipv4/igmp.c          | 18 +++++-------------
 net/ipv4/ip_sockglue.c   | 19 ++++++++++++++-----
 net/ipv6/ipv6_sockglue.c | 18 ++++++++++++++----
 net/ipv6/mcast.c         | 10 +++-------
 6 files changed, 38 insertions(+), 31 deletions(-)

diff --git a/include/linux/igmp.h b/include/linux/igmp.h
index faa6586a5783..64ce8cd1cfaf 100644
--- a/include/linux/igmp.h
+++ b/include/linux/igmp.h
@@ -123,7 +123,7 @@ 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);
 extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
-               struct group_filter __user *optval, int __user *optlen);
+                       struct sockaddr_storage __user *p);
 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/net/ipv6.h b/include/net/ipv6.h
index 955badd1e8ff..900cc66311c4 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -1136,7 +1136,7 @@ int ip6_mc_source(int add, int omode, struct sock *sk,
                  struct group_source_req *pgsr);
 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
-                 struct group_filter __user *optval, int __user *optlen);
+                 struct sockaddr_storage __user *p);
 
 #ifdef CONFIG_PROC_FS
 int ac6_proc_init(struct net *net);
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 47f0502b2101..7b272bbed2b4 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -2565,9 +2565,9 @@ int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
 }
 
 int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
-       struct group_filter __user *optval, int __user *optlen)
+       struct sockaddr_storage __user *p)
 {
-       int err, i, count, copycount;
+       int i, count, copycount;
        struct sockaddr_in *psin;
        __be32 addr;
        struct ip_mc_socklist *pmc;
@@ -2583,37 +2583,29 @@ int ip_mc_gsfget(struct sock *sk, struct group_filter 
*gsf,
        if (!ipv4_is_multicast(addr))
                return -EINVAL;
 
-       err = -EADDRNOTAVAIL;
-
        for_each_pmc_rtnl(inet, pmc) {
                if (pmc->multi.imr_multiaddr.s_addr == addr &&
                    pmc->multi.imr_ifindex == gsf->gf_interface)
                        break;
        }
        if (!pmc)               /* must have a prior join */
-               goto done;
+               return -EADDRNOTAVAIL;
        gsf->gf_fmode = pmc->sfmode;
        psl = rtnl_dereference(pmc->sflist);
        count = psl ? psl->sl_count : 0;
        copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
        gsf->gf_numsrc = count;
-       if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
-           copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
-               return -EFAULT;
-       }
-       for (i = 0; i < copycount; i++) {
+       for (i = 0; i < copycount; i++, p++) {
                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(&optval->gf_slist[i], &ss, sizeof(ss)))
+               if (copy_to_user(p, &ss, sizeof(ss)))
                        return -EFAULT;
        }
        return 0;
-done:
-       return err;
 }
 
 /*
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 8f550cf4c1c0..8616c38bd420 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1473,19 +1473,28 @@ static int do_ip_getsockopt(struct sock *sk, int level, 
int optname,
        }
        case MCAST_MSFILTER:
        {
+               struct group_filter __user *p = (void __user *)optval;
                struct group_filter gsf;
+               const int size0 = offsetof(struct group_filter, gf_slist);
+               int num;
 
-               if (len < GROUP_FILTER_SIZE(0)) {
+               if (len < size0) {
                        err = -EINVAL;
                        goto out;
                }
-               if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
+               if (copy_from_user(&gsf, p, size0)) {
                        err = -EFAULT;
                        goto out;
                }
-               err = ip_mc_gsfget(sk, &gsf,
-                                  (struct group_filter __user *)optval,
-                                  optlen);
+               num = gsf.gf_numsrc;
+               err = ip_mc_gsfget(sk, &gsf, p->gf_slist);
+               if (err)
+                       goto out;
+               if (gsf.gf_numsrc < num)
+                       num = gsf.gf_numsrc;
+               if (put_user(GROUP_FILTER_SIZE(num), optlen) ||
+                   copy_to_user(p, &gsf, size0))
+                       err = -EFAULT;
                goto out;
        }
        case IP_MULTICAST_ALL:
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 1b4ad4f8dc42..6441e824b63b 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -1056,18 +1056,28 @@ static int do_ipv6_getsockopt(struct sock *sk, int 
level, int optname,
                break;
        case MCAST_MSFILTER:
        {
+               struct group_filter __user *p = (void __user *)optval;
                struct group_filter gsf;
+               const int size0 = offsetof(struct group_filter, gf_slist);
+               int num;
                int err;
 
-               if (len < GROUP_FILTER_SIZE(0))
+               if (len < size0)
                        return -EINVAL;
-               if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0)))
+               if (copy_from_user(&gsf, p, size0))
                        return -EFAULT;
                if (gsf.gf_group.ss_family != AF_INET6)
                        return -EADDRNOTAVAIL;
+               num = gsf.gf_numsrc;
                lock_sock(sk);
-               err = ip6_mc_msfget(sk, &gsf,
-                       (struct group_filter __user *)optval, optlen);
+               err = ip6_mc_msfget(sk, &gsf, p->gf_slist);
+               if (!err) {
+                       if (num > gsf.gf_numsrc)
+                               num = gsf.gf_numsrc;
+                       if (put_user(GROUP_FILTER_SIZE(num), optlen) ||
+                           copy_to_user(p, &gsf, size0))
+                               err = -EFAULT;
+               }
                release_sock(sk);
                return err;
        }
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index eaa4c2cc2fbb..97d796c7d6c0 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -547,7 +547,7 @@ int ip6_mc_msfilter(struct sock *sk, struct group_filter 
*gsf)
 }
 
 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
-       struct group_filter __user *optval, int __user *optlen)
+       struct sockaddr_storage *p)
 {
        int err, i, count, copycount;
        const struct in6_addr *group;
@@ -592,14 +592,10 @@ int ip6_mc_msfget(struct sock *sk, struct group_filter 
*gsf,
 
        copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
        gsf->gf_numsrc = count;
-       if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
-           copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
-               return -EFAULT;
-       }
        /* changes to psl require the socket lock, and a write lock
         * on pmc->sflock. We have the socket lock so reading here is safe.
         */
-       for (i = 0; i < copycount; i++) {
+       for (i = 0; i < copycount; i++, p++) {
                struct sockaddr_in6 *psin6;
                struct sockaddr_storage ss;
 
@@ -607,7 +603,7 @@ int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
                memset(&ss, 0, sizeof(ss));
                psin6->sin6_family = AF_INET6;
                psin6->sin6_addr = psl->sl_addr[i];
-               if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
+               if (copy_to_user(p, &ss, sizeof(ss)))
                        return -EFAULT;
        }
        return 0;
-- 
2.11.0

Reply via email to