[PATCH] knfsd: SUNRPC: teach svc_sendto() to deal with IPv6 addresses

CMSG_DATA comes in different sizes, depending on address family.

[akpm@linux-foundation.org: remove unneeded do/while (0)]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 48 insertions, 17 deletions

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 9d7a819149ce..a89d04bd3855 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -36,6 +36,7 @@
 #include <net/sock.h>
 #include <net/checksum.h>
 #include <net/ip.h>
+#include <net/ipv6.h>
 #include <net/tcp_states.h>
 #include <asm/uaccess.h>
 #include <asm/ioctls.h>
@@ -446,6 +447,43 @@ svc_wake_up(struct svc_serv *serv)
         }
 }
 
+union svc_pktinfo_u {
+        struct in_pktinfo pkti;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+        struct in6_pktinfo pkti6;
+#endif
+};
+
+static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
+{
+        switch (rqstp->rq_sock->sk_sk->sk_family) {
+        case AF_INET: {
+                        struct in_pktinfo *pki = CMSG_DATA(cmh);
+
+                        cmh->cmsg_level = SOL_IP;
+                        cmh->cmsg_type = IP_PKTINFO;
+                        pki->ipi_ifindex = 0;
+                        pki->ipi_spec_dst.s_addr = rqstp->rq_daddr.addr.s_addr;
+                        cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
+                }
+                break;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+        case AF_INET6: {
+                        struct in6_pktinfo *pki = CMSG_DATA(cmh);
+
+                        cmh->cmsg_level = SOL_IPV6;
+                        cmh->cmsg_type = IPV6_PKTINFO;
+                        pki->ipi6_ifindex = 0;
+                        ipv6_addr_copy(&pki->ipi6_addr,
+                                        &rqstp->rq_daddr.addr6);
+                        cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
+                }
+                break;
+#endif
+        }
+        return;
+}
+
 /*
  * Generic sendto routine
  */
@@ -455,9 +493,8 @@ svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
         struct svc_sock *svsk = rqstp->rq_sock;
         struct socket   *sock = svsk->sk_sock;
         int             slen;
-        char            buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
+        char            buffer[CMSG_SPACE(sizeof(union svc_pktinfo_u))];
         struct cmsghdr *cmh = (struct cmsghdr *)buffer;
-        struct in_pktinfo *pki = (struct in_pktinfo *)CMSG_DATA(cmh);
         int             len = 0;
         int             result;
         int             size;
@@ -470,21 +507,15 @@ svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
         slen = xdr->len;
 
         if (rqstp->rq_prot == IPPROTO_UDP) {
-                /* set the source and destination */
-                struct msghdr   msg;
-                msg.msg_name    = &rqstp->rq_addr;
-                msg.msg_namelen = rqstp->rq_addrlen;
-                msg.msg_iov     = NULL;
-                msg.msg_iovlen  = 0;
-                msg.msg_flags   = MSG_MORE;
-
-                msg.msg_control = cmh;
-                msg.msg_controllen = sizeof(buffer);
-                cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
-                cmh->cmsg_level = SOL_IP;
-                cmh->cmsg_type = IP_PKTINFO;
-                pki->ipi_ifindex = 0;
-                pki->ipi_spec_dst.s_addr = rqstp->rq_daddr.addr.s_addr;
+                struct msghdr msg = {
+                        .msg_name       = &rqstp->rq_addr,
+                        .msg_namelen    = rqstp->rq_addrlen,
+                        .msg_control    = cmh,
+                        .msg_controllen = sizeof(buffer),
+                        .msg_flags      = MSG_MORE,
+                };
+
+                svc_set_cmsg_data(rqstp, cmh);
 
                 if (sock_sendmsg(sock, &msg, 0) < 0)
                         goto out;