IO: Minor changes in socket AF handing

AF can be specified implicitly by saddr or daddr, flags SKF_V4ONLY and
SKF_V6ONLY are to be removed.

3 files changed, 54 insertions, 23 deletions

diff --git a/sysdep/linux/sysio.h b/sysdep/linux/sysio.h
index 3c07a3e7..58644417 100644
--- a/sysdep/linux/sysio.h
+++ b/sysdep/linux/sysio.h
@@ -184,7 +184,7 @@ sk_set_md5_auth(sock *s, ip_addr local UNUSED, ip_addr remote, struct iface *ifa
   struct tcp_md5sig md5;
 
   memset(&md5, 0, sizeof(md5));
-  sockaddr_fill((sockaddr *) &md5.tcpm_addr, fam_to_af[s->fam], remote, ifa, 0);
+  sockaddr_fill((sockaddr *) &md5.tcpm_addr, s->af, remote, ifa, 0);
 
   if (passwd)
   {
diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c
index 69c17d60..48f368a4 100644
--- a/sysdep/unix/io.c
+++ b/sysdep/unix/io.c
@@ -587,7 +587,6 @@ sockaddr_read(sockaddr *sa, int af, ip_addr *a, struct iface **ifa, uint *port)
   return -1;
 }
 
-const int fam_to_af[] = { [SK_FAM_IPV4] = AF_INET, [SK_FAM_IPV6] = AF_INET6 };
 
 /*
  *	IPv6 multicast syscalls
@@ -1194,7 +1193,7 @@ sk_setup(sock *s)
   if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
     ERR("O_NONBLOCK");
 
-  if (!s->fam)
+  if (!s->af)
     return 0;
 
   if (ipa_nonzero(s->saddr) && !(s->flags & SKF_BIND))
@@ -1254,9 +1253,8 @@ sk_setup(sock *s)
 
   if (sk_is_ipv6(s))
   {
-    if (s->flags & SKF_V6ONLY)
-      if (setsockopt(fd, SOL_IPV6, IPV6_V6ONLY, &y, sizeof(y)) < 0)
-	ERR("IPV6_V6ONLY");
+    if (setsockopt(fd, SOL_IPV6, IPV6_V6ONLY, &y, sizeof(y)) < 0)
+      ERR("IPV6_V6ONLY");
 
     if (s->flags & SKF_LADDR_RX)
       if (sk_request_cmsg6_pktinfo(s) < 0)
@@ -1295,7 +1293,7 @@ sk_tcp_connected(sock *s)
   int sa_len = sizeof(sa);
 
   if ((getsockname(s->fd, &sa.sa, &sa_len) < 0) ||
-      (sockaddr_read(&sa, fam_to_af[s->fam], &s->saddr, &s->iface, &s->sport) < 0))
+      (sockaddr_read(&sa, s->af, &s->saddr, &s->iface, &s->sport) < 0))
     log(L_WARN "SOCK: Cannot get local IP address for TCP>");
 
   s->type = SK_TCP;
@@ -1320,7 +1318,7 @@ sk_passive_connected(sock *s, int type)
 
   sock *t = sk_new(s->pool);
   t->type = type;
-  t->fam = s->fam;
+  t->af = s->af;
   t->fd = fd;
   t->ttl = s->ttl;
   t->tos = s->tos;
@@ -1330,10 +1328,10 @@ sk_passive_connected(sock *s, int type)
   if (type == SK_TCP)
   {
     if ((getsockname(fd, &loc_sa.sa, &loc_sa_len) < 0) ||
-	(sockaddr_read(&loc_sa, fam_to_af[s->fam], &t->saddr, &t->iface, &t->sport) < 0))
+	(sockaddr_read(&loc_sa, s->af, &t->saddr, &t->iface, &t->sport) < 0))
       log(L_WARN "SOCK: Cannot get local IP address for TCP<");
 
-    if (sockaddr_read(&rem_sa, fam_to_af[s->fam], &t->daddr, &t->iface, &t->dport) < 0)
+    if (sockaddr_read(&rem_sa, s->af, &t->daddr, &t->iface, &t->dport) < 0)
       log(L_WARN "SOCK: Cannot get remote IP address for TCP<");
   }
 
@@ -1368,40 +1366,74 @@ sk_passive_connected(sock *s, int type)
 int
 sk_open(sock *s)
 {
+  int af = AF_UNSPEC;
   int fd = -1;
   int do_bind = 0;
   int bind_port = 0;
   ip_addr bind_addr = IPA_NONE;
   sockaddr sa;
 
+  if (s->type <= SK_IP)
+  {
+    /*
+     * For TCP/IP sockets, Address family (IPv4 or IPv6) can be specified either
+     * explicitly (SK_IPV4 or SK_IPV6) or implicitly (based on saddr, daddr).
+     * But the specifications have to be consistent.
+     */
+
+    switch (s->subtype)
+    {
+    case 0:
+      ASSERT(ipa_zero(s->saddr) || ipa_zero(s->daddr) ||
+	     (ipa_is_ip4(s->saddr) == ipa_is_ip4(s->daddr)));
+      af = (ipa_is_ip4(s->saddr) || ipa_is_ip4(s->daddr)) ? AF_INET : AF_INET6;
+      break;
+
+    case SK_IPV4:
+      ASSERT(ipa_zero(s->saddr) || ipa_is_ip4(s->saddr));
+      ASSERT(ipa_zero(s->daddr) || ipa_is_ip4(s->daddr));
+      af = AF_INET;
+      break;
+
+    case SK_IPV6:
+      ASSERT(ipa_zero(s->saddr) || !ipa_is_ip4(s->saddr));
+      ASSERT(ipa_zero(s->daddr) || !ipa_is_ip4(s->daddr));
+      af = AF_INET6;
+      break;
+
+    default:
+      bug("Invalid subtype %d", s->subtype);
+    }
+  }
+
   switch (s->type)
   {
   case SK_TCP_ACTIVE:
     s->ttx = "";			/* Force s->ttx != s->tpos */
     /* Fall thru */
   case SK_TCP_PASSIVE:
-    fd = socket(fam_to_af[s->fam], SOCK_STREAM, IPPROTO_TCP);
+    fd = socket(af, SOCK_STREAM, IPPROTO_TCP);
     bind_port = s->sport;
     bind_addr = s->saddr;
     do_bind = bind_port || ipa_nonzero(bind_addr);
     break;
 
   case SK_UDP:
-    fd = socket(fam_to_af[s->fam], SOCK_DGRAM, IPPROTO_UDP);
+    fd = socket(af, SOCK_DGRAM, IPPROTO_UDP);
     bind_port = s->sport;
     bind_addr = (s->flags & SKF_BIND) ? s->saddr : IPA_NONE;
     do_bind = 1;
     break;
 
   case SK_IP:
-    fd = socket(fam_to_af[s->fam], SOCK_RAW, s->dport);
+    fd = socket(af, SOCK_RAW, s->dport);
     bind_port = 0;
     bind_addr = (s->flags & SKF_BIND) ? s->saddr : IPA_NONE;
     do_bind = ipa_nonzero(bind_addr);
     break;
 
   case SK_MAGIC:
-    s->fam = SK_FAM_NONE;
+    af = 0;
     fd = s->fd;
     break;
 
@@ -1412,6 +1444,7 @@ sk_open(sock *s)
   if (fd < 0)
     ERR("socket");
 
+  s->af = af;
   s->fd = fd;
 
   if (sk_setup(s) < 0)
@@ -1440,7 +1473,7 @@ sk_open(sock *s)
 	if (sk_set_high_port(s) < 0)
 	  log(L_WARN "Socket error: %s%#m", s->err);
 
-    sockaddr_fill(&sa, fam_to_af[s->fam], bind_addr, s->iface, bind_port);
+    sockaddr_fill(&sa, s->af, bind_addr, s->iface, bind_port);
     if (bind(fd, &sa.sa, SA_LEN(sa)) < 0)
       ERR2("bind");
   }
@@ -1452,7 +1485,7 @@ sk_open(sock *s)
   switch (s->type)
   {
   case SK_TCP_ACTIVE:
-    sockaddr_fill(&sa, fam_to_af[s->fam], s->daddr, s->iface, s->dport);
+    sockaddr_fill(&sa, s->af, s->daddr, s->iface, s->dport);
     if (connect(fd, &sa.sa, SA_LEN(sa)) >= 0)
       sk_tcp_connected(s);
     else if (errno != EINTR && errno != EAGAIN && errno != EINPROGRESS &&
@@ -1559,7 +1592,7 @@ sk_sendmsg(sock *s)
   byte cmsg_buf[CMSG_TX_SPACE];
   sockaddr dst;
 
-  sockaddr_fill(&dst, fam_to_af[s->fam], s->daddr, s->iface, s->dport);
+  sockaddr_fill(&dst, s->af, s->daddr, s->iface, s->dport);
 
   struct msghdr msg = {
     .msg_name = &dst.sa,
@@ -1612,7 +1645,7 @@ sk_recvmsg(sock *s)
   //    rv = ipv4_skip_header(pbuf, rv);
   //endif
 
-  sockaddr_read(&src, fam_to_af[s->fam], &s->faddr, NULL, &s->fport);
+  sockaddr_read(&src, s->af, &s->faddr, NULL, &s->fport);
   sk_process_cmsgs(s, &msg);
 
   if (msg.msg_flags & MSG_TRUNC)
@@ -1832,7 +1865,7 @@ sk_write(sock *s)
   case SK_TCP_ACTIVE:
     {
       sockaddr sa;
-      sockaddr_fill(&sa, fam_to_af[s->fam], s->daddr, s->iface, s->dport);
+      sockaddr_fill(&sa, s->af, s->daddr, s->iface, s->dport);
 
       if (connect(s->fd, &sa.sa, SA_LEN(sa)) >= 0 || errno == EISCONN)
 	sk_tcp_connected(s);
@@ -1853,10 +1886,10 @@ sk_write(sock *s)
 }
 
 int sk_is_ipv4(sock *s)
-{ return s->fam == SK_FAM_IPV4; }
+{ return s->af == AF_INET; }
 
 int sk_is_ipv6(sock *s)
-{ return s->fam == SK_FAM_IPV6; }
+{ return s->af == AF_INET6; }
 
 void
 sk_dump_all(void)
diff --git a/sysdep/unix/unix.h b/sysdep/unix/unix.h
index 80c99350..dcaab729 100644
--- a/sysdep/unix/unix.h
+++ b/sysdep/unix/unix.h
@@ -102,8 +102,6 @@ int sk_open_unix(struct birdsock *s, char *name);
 void *tracked_fopen(struct pool *, char *name, char *mode);
 void test_old_bird(char *path);
 
-extern const int fam_to_af[];
-
 /* krt.c bits */
 
 void krt_io_init(void);