From 9247685088398cf21bcb513bd2832b4cd42516c4 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Wed, 20 Oct 2010 11:53:01 -0400 Subject: [PATCH] SUNRPC: Properly initialize sock_xprt.srcaddr in all cases The source address field in the transport's sock_xprt is initialized ONLY IF the RPC application passed a pointer to a source address during the call to rpc_create(). However, xs_bind() subsequently uses the value of this field without regard to whether the source address was initialized during transport creation or not. So far we've been lucky: the uninitialized value of this field is zeroes. xs_bind(), until recently, used only the sin[6]_addr field in this sockaddr, and all zeroes is a valid value for this: it means ANYADDR. This is a happy coincidence. However, xs_bind() now wants to use the sa_family field as well, and expects it to be initialized to something other than zero. Therefore, the source address sockaddr field should be fully initialized at transport create time in _every_ case, not just when the RPC application wants to use a specific bind address. Bruce added a workaround for this missing initialization by adjusting commit 6bc9638a, but the "right" way to do this is to ensure that the source address sockaddr is always correctly initialized from the get-go. This patch doesn't introduce a behavior change. It's simply a clean-up of Bruce's fix, to prevent future problems of this kind. It may look like overkill, but a) it clearly documents the default initial value of this field, b) it doesn't assume that the sockaddr_storage memory is first initialized to any particular value, and c) it will fail verbosely if some unknown address family is passed in Originally introduced by commit d3bc9a1d. Signed-off-by: Chuck Lever Signed-off-by: J. Bruce Fields --- net/sunrpc/xprtsock.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index b58eef76a518..27fc4b4cb82b 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1629,7 +1629,6 @@ static struct socket *xs_create_sock(struct rpc_xprt *xprt, protocol, -err); goto out; } - transport->srcaddr.ss_family = family; xs_reclassify_socket(family, sock); if (xs_bind(transport, sock)) { @@ -2136,6 +2135,31 @@ static struct rpc_xprt_ops bc_tcp_ops = { .print_stats = xs_tcp_print_stats, }; +static int xs_init_anyaddr(const int family, struct sockaddr *sap) +{ + static const struct sockaddr_in sin = { + .sin_family = AF_INET, + .sin_addr.s_addr = htonl(INADDR_ANY), + }; + static const struct sockaddr_in6 sin6 = { + .sin6_family = AF_INET6, + .sin6_addr = IN6ADDR_ANY_INIT, + }; + + switch (family) { + case AF_INET: + memcpy(sap, &sin, sizeof(sin)); + break; + case AF_INET6: + memcpy(sap, &sin6, sizeof(sin6)); + break; + default: + dprintk("RPC: %s: Bad address family\n", __func__); + return -EAFNOSUPPORT; + } + return 0; +} + static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args, unsigned int slot_table_size) { @@ -2159,6 +2183,13 @@ static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args, xprt->addrlen = args->addrlen; if (args->srcaddr) memcpy(&new->srcaddr, args->srcaddr, args->addrlen); + else { + int err; + err = xs_init_anyaddr(args->dstaddr->sa_family, + (struct sockaddr *)&new->srcaddr); + if (err != 0) + return ERR_PTR(err); + } return xprt; }