[Qemu-devel] [PATCH 06/18] slirp: Factorizing and cleaning solookup()

[Samuel Thibault]

This patch makes solookup() compatible with varying address families. Also,
this function was only compatible with TCP. Having the socket list in
argument, it is now compatible with UDP too. Finally, some optimization
code is factorized inside the function (the function look at the last
returned result before browsing the complete socket list).

This also adds a sockaddr_equal() function to compare two
sockaddr_storage.

Signed-off-by: Guillaume Subiron <address@hidden>
---
 slirp/socket.c    | 30 ++++++++++++++++--------------
 slirp/socket.h    | 23 ++++++++++++++++++++++-
 slirp/tcp_input.c | 27 +++++++++++----------------
 slirp/udp.c       | 25 ++++++-------------------
 4 files changed, 55 insertions(+), 50 deletions(-)

diff --git a/slirp/socket.c b/slirp/socket.c
index 146d693..3fd0667 100644
--- a/slirp/socket.c
+++ b/slirp/socket.c
@@ -15,24 +15,26 @@
 static void sofcantrcvmore(struct socket *so);
 static void sofcantsendmore(struct socket *so);
 
-struct socket *
-solookup(struct socket *head, struct in_addr laddr, u_int lport,
-         struct in_addr faddr, u_int fport)
+struct socket *solookup(struct socket **last, struct socket *head,
+        struct sockaddr_storage *lhost, struct sockaddr_storage *fhost)
 {
-       struct socket *so;
+    struct socket *so = *last;
 
-       for (so = head->so_next; so != head; so = so->so_next) {
-               if (so->so_lport == lport &&
-                   so->so_laddr.s_addr == laddr.s_addr &&
-                   so->so_faddr.s_addr == faddr.s_addr &&
-                   so->so_fport == fport)
-                  break;
-       }
+    /* Optimisation */
+    if (so != head && sockaddr_equal(&(so->lhost.ss), lhost)
+            && (!fhost || sockaddr_equal(&(so->fhost.ss), fhost))) {
+        return so;
+    }
 
-       if (so == head)
-          return (struct socket *)NULL;
-       return so;
+    for (so = head->so_next; so != head; so = so->so_next) {
+        if (sockaddr_equal(&(so->lhost.ss), lhost)
+                && (!fhost || sockaddr_equal(&(so->fhost.ss), fhost))) {
+            *last = so;
+            return so;
+        }
+    }
 
+    return (struct socket *)NULL;
 }
 
 /*
diff --git a/slirp/socket.h b/slirp/socket.h
index b27bbb2..644216c 100644
--- a/slirp/socket.h
+++ b/slirp/socket.h
@@ -87,7 +87,28 @@ struct socket {
 #define SS_HOSTFWD             0x1000  /* Socket describes host->guest 
forwarding */
 #define SS_INCOMING            0x2000  /* Connection was initiated by a host 
on the internet */
 
-struct socket * solookup(struct socket *, struct in_addr, u_int, struct 
in_addr, u_int);
+static inline int sockaddr_equal(struct sockaddr_storage *a,
+        struct sockaddr_storage *b)
+{
+    if (a->ss_family != b->ss_family) {
+        return 0;
+    } else {
+        switch (a->ss_family) {
+        case AF_INET:
+        {
+            struct sockaddr_in *a4 = (struct sockaddr_in *) a;
+            struct sockaddr_in *b4 = (struct sockaddr_in *) b;
+            return (a4->sin_addr.s_addr == b4->sin_addr.s_addr
+                    && a4->sin_port == b4->sin_port);
+        }
+        default:
+            assert(0);
+        }
+    }
+}
+
+struct socket *solookup(struct socket **, struct socket *,
+        struct sockaddr_storage *, struct sockaddr_storage *);
 struct socket * socreate(Slirp *);
 void sofree(struct socket *);
 int soread(struct socket *);
diff --git a/slirp/tcp_input.c b/slirp/tcp_input.c
index 4b1a383..1b9a0b1 100644
--- a/slirp/tcp_input.c
+++ b/slirp/tcp_input.c
@@ -227,6 +227,7 @@ tcp_input(struct mbuf *m, int iphlen, struct socket *inso)
        int iss = 0;
        u_long tiwin;
        int ret;
+       struct sockaddr_storage lhost, fhost;
     struct ex_list *ex_ptr;
     Slirp *slirp;
 
@@ -320,16 +321,14 @@ tcp_input(struct mbuf *m, int iphlen, struct socket *inso)
         * Locate pcb for segment.
         */
 findso:
-       so = slirp->tcp_last_so;
-       if (so->so_fport != ti->ti_dport ||
-           so->so_lport != ti->ti_sport ||
-           so->so_laddr.s_addr != ti->ti_src.s_addr ||
-           so->so_faddr.s_addr != ti->ti_dst.s_addr) {
-               so = solookup(&slirp->tcb, ti->ti_src, ti->ti_sport,
-                              ti->ti_dst, ti->ti_dport);
-               if (so)
-                       slirp->tcp_last_so = so;
-       }
+       lhost.ss_family = AF_INET;
+       ((struct sockaddr_in *)&lhost)->sin_addr = ti->ti_src;
+       ((struct sockaddr_in *)&lhost)->sin_port = ti->ti_sport;
+       fhost.ss_family = AF_INET;
+       ((struct sockaddr_in *)&fhost)->sin_addr = ti->ti_dst;
+       ((struct sockaddr_in *)&fhost)->sin_port = ti->ti_dport;
+
+       so = solookup(&slirp->tcp_last_so, &slirp->tcb, &lhost, &fhost);
 
        /*
         * If the state is CLOSED (i.e., TCB does not exist) then
@@ -374,12 +373,8 @@ findso:
          sbreserve(&so->so_snd, TCP_SNDSPACE);
          sbreserve(&so->so_rcv, TCP_RCVSPACE);
 
-         so->so_lfamily = AF_INET;
-         so->so_laddr = ti->ti_src;
-         so->so_lport = ti->ti_sport;
-         so->so_ffamily = AF_INET;
-         so->so_faddr = ti->ti_dst;
-         so->so_fport = ti->ti_dport;
+         so->lhost.ss = lhost;
+         so->fhost.ss = fhost;
 
          if ((so->so_iptos = tcp_tos(so)) == 0)
            so->so_iptos = ((struct ip *)ti)->ip_tos;
diff --git a/slirp/udp.c b/slirp/udp.c
index 25d35d1..fbf2362 100644
--- a/slirp/udp.c
+++ b/slirp/udp.c
@@ -70,6 +70,7 @@ udp_input(register struct mbuf *m, int iphlen)
        int len;
        struct ip save_ip;
        struct socket *so;
+       struct sockaddr_storage lhost;
 
        DEBUG_CALL("udp_input");
        DEBUG_ARG("m = %lx", (long)m);
@@ -151,25 +152,11 @@ udp_input(register struct mbuf *m, int iphlen)
        /*
         * Locate pcb for datagram.
         */
-       so = slirp->udp_last_so;
-       if (so == &slirp->udb || so->so_lport != uh->uh_sport ||
-           so->so_laddr.s_addr != ip->ip_src.s_addr) {
-               struct socket *tmp;
-
-               for (tmp = slirp->udb.so_next; tmp != &slirp->udb;
-                    tmp = tmp->so_next) {
-                       if (tmp->so_lport == uh->uh_sport &&
-                           tmp->so_laddr.s_addr == ip->ip_src.s_addr) {
-                               so = tmp;
-                               break;
-                       }
-               }
-               if (tmp == &slirp->udb) {
-                 so = NULL;
-               } else {
-                 slirp->udp_last_so = so;
-               }
-       }
+       lhost.ss_family = AF_INET;
+       ((struct sockaddr_in *)&lhost)->sin_addr = ip->ip_src;
+       ((struct sockaddr_in *)&lhost)->sin_port = uh->uh_sport;
+
+       so = solookup(&slirp->udp_last_so, &slirp->udb, &lhost, NULL);
 
        if (so == NULL) {
          /*
-- 
2.4.6