ipv4: processing ancillary IP_TOS or IP_TTL

If IP_TOS or IP_TTL are specified as ancillary data, then sendmsg() sends out
packets with the specified TTL or TOS overriding the socket values specified
with the traditional setsockopt().

The struct inet_cork stores the values of TOS, TTL and priority that are
passed through the struct ipcm_cookie. If there are user-specified TOS
(tos != -1) or TTL (ttl != 0) in the struct ipcm_cookie, these values are
used to override the per-socket values. In case of TOS also the priority
is changed accordingly.

Two helper functions get_rttos and get_rtconn_flags are defined to take
into account the presence of a user specified TOS value when computing
RT_TOS and RT_CONN_FLAGS.

Signed-off-by: Francesco Fusco <ffusco@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 636d203727a2dcef09f2f8f0b2e214c317c7675a..f3141773c14d12b27250162cbf0a5ba19c0d13c1 100644 (file)
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -103,6 +103,9 @@ struct inet_cork {
        int                     length; /* Total length of all frames */
        struct dst_entry        *dst;
        u8                      tx_flags;
+       __u8                    ttl;
+       __s16                   tos;
+       char                    priority;
 };
 
 struct inet_cork_full {

diff --git a/include/net/ip.h b/include/net/ip.h
index 0135f3823e66f215899d6cffa25c1552c2e7487f..77b4f9b57c288fc8884fa3e2de20649c2bf69228 100644 (file)
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -28,6 +28,7 @@
 #include <linux/skbuff.h>
 
 #include <net/inet_sock.h>
+#include <net/route.h>
 #include <net/snmp.h>
 #include <net/flow.h>
 
@@ -140,6 +141,16 @@ static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
        return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
 }
 
+static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
+{
+       return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
+}
+
+static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
+{
+       return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
+}
+
 /* datagram.c */
 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 

diff --git a/include/net/route.h b/include/net/route.h
index 6f572ca66d2521fc6b8d093fea27022a4ac9d147..0ad8e0102386943a8087a7bbded76ac082b63e96 100644 (file)
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -39,6 +39,7 @@
 #define RTO_ONLINK     0x01
 
 #define RT_CONN_FLAGS(sk)   (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))
+#define RT_CONN_FLAGS_TOS(sk,tos)   (RT_TOS(tos) | sock_flag(sk, SOCK_LOCALROUTE))
 
 struct fib_nh;
 struct fib_info;

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 5f7d11a458713f9c755dd1a1a40289b180a3e041..5c0e8bc6e5ba275d2469336533b5848de94ae6c1 100644 (file)
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -353,6 +353,9 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
        saddr = fib_compute_spec_dst(skb);
        ipc.opt = NULL;
        ipc.tx_flags = 0;
+       ipc.ttl = 0;
+       ipc.tos = -1;
+
        if (icmp_param->replyopts.opt.opt.optlen) {
                ipc.opt = &icmp_param->replyopts.opt;
                if (ipc.opt->opt.srr)
@@ -608,6 +611,8 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
        ipc.addr = iph->saddr;
        ipc.opt = &icmp_param->replyopts.opt;
        ipc.tx_flags = 0;
+       ipc.ttl = 0;
+       ipc.tos = -1;
 
        rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos,
                               type, code, icmp_param);

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index a04d872c54f919c7133e7830773301cdf070f3ed..7d8357bb2ba654a88fbf564897beb88e412f4974 100644 (file)
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1060,6 +1060,9 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
                         rt->dst.dev->mtu : dst_mtu(&rt->dst);
        cork->dst = &rt->dst;
        cork->length = 0;
+       cork->ttl = ipc->ttl;
+       cork->tos = ipc->tos;
+       cork->priority = ipc->priority;
        cork->tx_flags = ipc->tx_flags;
 
        return 0;
@@ -1311,7 +1314,9 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
        if (cork->flags & IPCORK_OPT)
                opt = cork->opt;
 
-       if (rt->rt_type == RTN_MULTICAST)
+       if (cork->ttl != 0)
+               ttl = cork->ttl;
+       else if (rt->rt_type == RTN_MULTICAST)
                ttl = inet->mc_ttl;
        else
                ttl = ip_select_ttl(inet, &rt->dst);
@@ -1319,7 +1324,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
        iph = ip_hdr(skb);
        iph->version = 4;
        iph->ihl = 5;
-       iph->tos = inet->tos;
+       iph->tos = (cork->tos != -1) ? cork->tos : inet->tos;
        iph->frag_off = df;
        iph->ttl = ttl;
        iph->protocol = sk->sk_protocol;
@@ -1331,7 +1336,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
                ip_options_build(skb, opt, cork->addr, rt, 0);
        }
 
-       skb->priority = sk->sk_priority;
+       skb->priority = (cork->tos != -1) ? cork->priority: sk->sk_priority;
        skb->mark = sk->sk_mark;
        /*
         * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec
@@ -1481,6 +1486,8 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr,
        ipc.addr = daddr;
        ipc.opt = NULL;
        ipc.tx_flags = 0;
+       ipc.ttl = 0;
+       ipc.tos = -1;
 
        if (replyopts.opt.opt.optlen) {
                ipc.opt = &replyopts.opt;

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index d7d9882d4caea169964a58e294ffe6c73a99d36c..706d108e128c7a6ee9bab304d50ed2e761086632 100644 (file)
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -713,6 +713,8 @@ int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
        ipc.opt = NULL;
        ipc.oif = sk->sk_bound_dev_if;
        ipc.tx_flags = 0;
+       ipc.ttl = 0;
+       ipc.tos = -1;
 
        sock_tx_timestamp(sk, &ipc.tx_flags);
 
@@ -744,7 +746,7 @@ int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                        return -EINVAL;
                faddr = ipc.opt->opt.faddr;
        }
-       tos = RT_TOS(inet->tos);
+       tos = get_rttos(&ipc, inet);
        if (sock_flag(sk, SOCK_LOCALROUTE) ||
            (msg->msg_flags & MSG_DONTROUTE) ||
            (ipc.opt && ipc.opt->opt.is_strictroute)) {

diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index bfec521c717fd2320242c24e7a7f74a64c1c1a44..a3fe534c968eb0de7cb76d092831137566148596 100644 (file)
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -517,6 +517,8 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
        ipc.addr = inet->inet_saddr;
        ipc.opt = NULL;
        ipc.tx_flags = 0;
+       ipc.ttl = 0;
+       ipc.tos = -1;
        ipc.oif = sk->sk_bound_dev_if;
 
        if (msg->msg_controllen) {
@@ -556,7 +558,7 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                        daddr = ipc.opt->opt.faddr;
                }
        }
-       tos = RT_CONN_FLAGS(sk);
+       tos = get_rtconn_flags(&ipc, sk);
        if (msg->msg_flags & MSG_DONTROUTE)
                tos |= RTO_ONLINK;
 

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 74d2c95db57f3768d62ee450ed6bab64ca09b26d..22462d947750446006798583ed8fc66e72ddeb33 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -855,6 +855,8 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 
        ipc.opt = NULL;
        ipc.tx_flags = 0;
+       ipc.ttl = 0;
+       ipc.tos = -1;
 
        getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
 
@@ -938,7 +940,7 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                faddr = ipc.opt->opt.faddr;
                connected = 0;
        }
-       tos = RT_TOS(inet->tos);
+       tos = get_rttos(&ipc, inet);
        if (sock_flag(sk, SOCK_LOCALROUTE) ||
            (msg->msg_flags & MSG_DONTROUTE) ||
            (ipc.opt && ipc.opt->opt.is_strictroute)) {