Declare address parameter in TCP SYN cache const.

tcp6_ctlinput() casted a constant sockaddr_sin6 to non-const sockaddr.
sa6_src may be &sa6_any which lives in read-only data section.
Better pass down the const addresses to syn_cache_lookup().  They
are needed for hash lookup and are not modified.

OK mvs@

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 8750128..75aa39d 100644 (file)
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: tcp_input.c,v 1.398 2024/01/11 13:49:49 bluhm Exp $   */
+/*     $OpenBSD: tcp_input.c,v 1.399 2024/01/27 21:13:46 bluhm Exp $   */
 /*     $NetBSD: tcp_input.c,v 1.23 1996/02/13 23:43:44 christos Exp $  */
 
 /*
@@ -201,8 +201,8 @@ int  syn_cache_add(struct sockaddr *, struct sockaddr *, struct tcphdr *,
 struct socket *syn_cache_get(struct sockaddr *, struct sockaddr *,
                struct tcphdr *, unsigned int, unsigned int, struct socket *,
                struct mbuf *, uint64_t);
-struct syn_cache *syn_cache_lookup(struct sockaddr *, struct sockaddr *,
-               struct syn_cache_head **, u_int);
+struct syn_cache *syn_cache_lookup(const struct sockaddr *,
+               const struct sockaddr *, struct syn_cache_head **, u_int);
 
 /*
  * Insert segment ti into reassembly queue of tcp with
@@ -3109,9 +3109,9 @@ struct mutex syn_cache_mtx = MUTEX_INITIALIZER(IPL_SOFTNET);
 #ifndef INET6
 #define        SYN_HASHALL(hash, src, dst, rand) \
 do {                                                                   \
-       hash = SYN_HASH(&satosin(src)->sin_addr,                        \
-               satosin(src)->sin_port,                                 \
-               satosin(dst)->sin_port, (rand));                        \
+       hash = SYN_HASH(&satosin_const(src)->sin_addr,                  \
+               satosin_const(src)->sin_port,                           \
+               satosin_const(dst)->sin_port, (rand));                  \
 } while (/*CONSTCOND*/ 0)
 #else
 #define SYN_HASH6(sa, sp, dp, rand) \
@@ -3125,14 +3125,14 @@ do {                                                                    \
 do {                                                                   \
        switch ((src)->sa_family) {                                     \
        case AF_INET:                                                   \
-               hash = SYN_HASH(&satosin(src)->sin_addr,                \
-                       satosin(src)->sin_port,                         \
-                       satosin(dst)->sin_port, (rand));                \
+               hash = SYN_HASH(&satosin_const(src)->sin_addr,          \
+                       satosin_const(src)->sin_port,                   \
+                       satosin_const(dst)->sin_port, (rand));          \
                break;                                                  \
        case AF_INET6:                                                  \
-               hash = SYN_HASH6(&satosin6(src)->sin6_addr,             \
-                       satosin6(src)->sin6_port,                       \
-                       satosin6(dst)->sin6_port, (rand));              \
+               hash = SYN_HASH6(&satosin6_const(src)->sin6_addr,       \
+                       satosin6_const(src)->sin6_port,                 \
+                       satosin6_const(dst)->sin6_port, (rand));        \
                break;                                                  \
        default:                                                        \
                hash = 0;                                               \
@@ -3423,7 +3423,7 @@ syn_cache_cleanup(struct tcpcb *tp)
  * Find an entry in the syn cache.
  */
 struct syn_cache *
-syn_cache_lookup(struct sockaddr *src, struct sockaddr *dst,
+syn_cache_lookup(const struct sockaddr *src, const struct sockaddr *dst,
     struct syn_cache_head **headp, u_int rtableid)
 {
        struct syn_cache_set *sets[2];
@@ -3709,8 +3709,8 @@ syn_cache_reset(struct sockaddr *src, struct sockaddr *dst, struct tcphdr *th,
 }
 
 void
-syn_cache_unreach(struct sockaddr *src, struct sockaddr *dst, struct tcphdr *th,
-    u_int rtableid)
+syn_cache_unreach(const struct sockaddr *src, const struct sockaddr *dst,
+    struct tcphdr *th, u_int rtableid)
 {
        struct syn_cache *sc;
        struct syn_cache_head *scp;

diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index 6d65aa8..8b5982a 100644 (file)
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: tcp_subr.c,v 1.195 2024/01/11 13:49:49 bluhm Exp $    */
+/*     $OpenBSD: tcp_subr.c,v 1.196 2024/01/27 21:13:46 bluhm Exp $    */
 /*     $NetBSD: tcp_subr.c,v 1.22 1996/02/13 23:44:00 christos Exp $   */
 
 /*
@@ -698,8 +698,8 @@ tcp6_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *d)
                } else if (inet6ctlerrmap[cmd] == EHOSTUNREACH ||
                    inet6ctlerrmap[cmd] == ENETUNREACH ||
                    inet6ctlerrmap[cmd] == EHOSTDOWN)
-                       syn_cache_unreach((struct sockaddr *)sa6_src,
-                           sa, &th, rdomain);
+                       syn_cache_unreach(sin6tosa_const(sa6_src), sa, &th,
+                           rdomain);
                in_pcbunref(inp);
        } else {
                in6_pcbnotify(&tcbtable, sa6, 0,

diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index 6f49506..0c5263f 100644 (file)
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: tcp_var.h,v 1.174 2024/01/11 13:49:49 bluhm Exp $     */
+/*     $OpenBSD: tcp_var.h,v 1.175 2024/01/27 21:13:46 bluhm Exp $     */
 /*     $NetBSD: tcp_var.h,v 1.17 1996/02/13 23:44:24 christos Exp $    */
 
 /*
@@ -799,7 +799,7 @@ int tcp_signature(struct tdb *, int, struct mbuf *, struct tcphdr *,
 #endif /* TCP_SIGNATURE */
 void     tcp_set_iss_tsm(struct tcpcb *);
 
-void    syn_cache_unreach(struct sockaddr *, struct sockaddr *,
+void    syn_cache_unreach(const struct sockaddr *, const struct sockaddr *,
           struct tcphdr *, u_int);
 void    syn_cache_init(void);
 void    syn_cache_cleanup(struct tcpcb *);

diff --git a/sys/netinet6/in6.h b/sys/netinet6/in6.h
index 936ef6c..98384bf 100644 (file)
--- a/sys/netinet6/in6.h
+++ b/sys/netinet6/in6.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: in6.h,v 1.111 2023/11/28 13:23:20 bluhm Exp $ */
+/*     $OpenBSD: in6.h,v 1.112 2024/01/27 21:13:46 bluhm Exp $ */
 /*     $KAME: in6.h,v 1.83 2001/03/29 02:55:07 jinmei Exp $    */
 
 /*
@@ -459,6 +459,12 @@ sin6tosa(struct sockaddr_in6 *sin6)
        return ((struct sockaddr *)(sin6));
 }
 
+static inline const struct sockaddr *
+sin6tosa_const(const struct sockaddr_in6 *sin6)
+{
+       return ((const struct sockaddr *)(sin6));
+}
+
 static inline struct in6_ifaddr *
 ifatoia6(struct ifaddr *ifa)
 {