[IPV4]: multicast API "join" issues

1) In the full-state API when imsf_numsrc == 0
   errno should be "0", but returns EADDRNOTAVAIL

2) An illegal filter mode change
   errno should be EINVAL, but returns EADDRNOTAVAIL

3) Trying to do an any-source option without IP_ADD_MEMBERSHIP
   errno should be EINVAL, but returns EADDRNOTAVAIL

4) Adds comments for the less obvious error return values

Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 6 deletions

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index e21ebe759907..dbbfa09de4e8 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1748,12 +1748,16 @@ int ip_mc_source(int add, int omode, struct sock *sk, struct
                     && pmc->multi.imr_ifindex == imr.imr_ifindex)
                         break;
         }
-        if (!pmc)               /* must have a prior join */
+        if (!pmc) {             /* must have a prior join */
+                err = -EINVAL;
                 goto done;
+        }
         /* if a source filter was set, must be the same mode as before */
         if (pmc->sflist) {
-                if (pmc->sfmode != omode)
+                if (pmc->sfmode != omode) {
+                        err = -EINVAL;
                         goto done;
+                }
         } else if (pmc->sfmode != omode) {
                 /* allow mode switches for empty-set filters */
                 ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
@@ -1765,7 +1769,7 @@ int ip_mc_source(int add, int omode, struct sock *sk, struct
         psl = pmc->sflist;
         if (!add) {
                 if (!psl)
-                        goto done;
+                        goto done;      /* err = -EADDRNOTAVAIL */
                 rv = !0;
                 for (i=0; i<psl->sl_count; i++) {
                         rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
@@ -1774,7 +1778,7 @@ int ip_mc_source(int add, int omode, struct sock *sk, struct
                                 break;
                 }
                 if (rv)         /* source not found */
-                        goto done;
+                        goto done;      /* err = -EADDRNOTAVAIL */
 
                 /* special case - (INCLUDE, empty) == LEAVE_GROUP */
                 if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
@@ -1870,15 +1874,16 @@ int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
                 err = -ENODEV;
                 goto done;
         }
-        err = -EADDRNOTAVAIL;
 
         for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
                 if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
                     pmc->multi.imr_ifindex == imr.imr_ifindex)
                         break;
         }
-        if (!pmc)               /* must have a prior join */
+        if (!pmc) {             /* must have a prior join */
+                err = -EINVAL;
                 goto done;
+        }
         if (msf->imsf_numsrc) {
                 newpsl = (struct ip_sf_socklist *)sock_kmalloc(sk,
                                 IP_SFLSIZE(msf->imsf_numsrc), GFP_KERNEL);
@@ -1907,6 +1912,7 @@ int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
                         0, NULL, 0);
         pmc->sflist = newpsl;
         pmc->sfmode = msf->imsf_fmode;
+        err = 0;
 done:
         rtnl_shunlock();
         return err;