1 files changed, 39 insertions, 24 deletions

diff --git a/sysdep/bsd/sysio.h b/sysdep/bsd/sysio.h
index 085f16fa..031eac9a 100644
--- a/sysdep/bsd/sysio.h
+++ b/sysdep/bsd/sysio.h
@@ -113,7 +113,9 @@ sysio_leave_group(sock *s, ip_addr maddr)
 /* BSD RX/TX packet info handling for IPv4 */
 /* it uses IP_RECVDSTADDR / IP_RECVIF socket options instead of IP_PKTINFO */
 
-#define CMSG_RX_SPACE (CMSG_SPACE(sizeof(struct in_addr)) + CMSG_SPACE(sizeof(struct sockaddr_dl)))
+#define CMSG_RX_SPACE (CMSG_SPACE(sizeof(struct in_addr)) + \
+		       CMSG_SPACE(sizeof(struct sockaddr_dl)) + \
+		       CMSG_SPACE(sizeof(char)))
 #define CMSG_TX_SPACE CMSG_SPACE(sizeof(struct in_addr))
 
 static char *
@@ -121,13 +123,18 @@ sysio_register_cmsgs(sock *s)
 {
   int ok = 1;
   if (s->flags & SKF_LADDR_RX)
-    {
-      if (setsockopt(s->fd, IPPROTO_IP, IP_RECVDSTADDR, &ok, sizeof(ok)) < 0)
-	return "IP_RECVDSTADDR";
+  {
+    if (setsockopt(s->fd, IPPROTO_IP, IP_RECVDSTADDR, &ok, sizeof(ok)) < 0)
+      return "IP_RECVDSTADDR";
+
+    if (setsockopt(s->fd, IPPROTO_IP, IP_RECVIF, &ok, sizeof(ok)) < 0)
+      return "IP_RECVIF";
+  }
+
+  if ((s->flags & SKF_TTL_RX) &&
+      (setsockopt(s->fd, IPPROTO_IP, IP_RECVTTL, &ok, sizeof(ok)) < 0))
+    return "IP_RECVTTL";
 
-      if (setsockopt(s->fd, IPPROTO_IP, IP_RECVIF, &ok, sizeof(ok)) < 0)
-	return "IP_RECVIF";
-    }
 
   return NULL;
 }
@@ -136,27 +143,35 @@ static void
 sysio_process_rx_cmsgs(sock *s, struct msghdr *msg)
 {
   struct cmsghdr *cm;
+  struct in_addr *ra = NULL;
+  struct sockaddr_dl *ri = NULL;
+  unsigned char *ttl = NULL;
 
-  if (!(s->flags & SKF_LADDR_RX))
-    return;
+  for (cm = CMSG_FIRSTHDR(msg); cm != NULL; cm = CMSG_NXTHDR(msg, cm))
+  {
+    if (cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_RECVDSTADDR)
+      ra = (struct in_addr *) CMSG_DATA(cm);
 
-  s->laddr = IPA_NONE;
-  s->lifindex = 0;
+    if (cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_RECVIF)
+      ri = (struct sockaddr_dl *) CMSG_DATA(cm);
 
-  for (cm = CMSG_FIRSTHDR(msg); cm != NULL; cm = CMSG_NXTHDR(msg, cm))
-    {
-      if (cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_RECVDSTADDR)
-	{
-	  struct in_addr *ra = (struct in_addr *) CMSG_DATA(cm);
-	  get_inaddr(&s->laddr, ra);
-	}
+    if (cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_RECVTTL)
+      ttl = (unsigned char *) CMSG_DATA(cm);
+  }
 
-      if (cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_RECVIF)
-	{
-	  struct sockaddr_dl *ri = (struct sockaddr_dl *) CMSG_DATA(cm);
-	  s->lifindex = ri->sdl_index;
-	}
-    }
+  if (s->flags & SKF_LADDR_RX)
+  {
+    s->laddr = IPA_NONE;
+    s->lifindex = 0;
+
+    if (ra)
+      get_inaddr(&s->laddr, ra);
+    if (ri)
+      s->lifindex = ri->sdl_index;
+  }
+
+  if (s->flags & SKF_TTL_RX)
+    s->ttl = ttl ? *ttl : -1;
 
   // log(L_WARN "RX %I %d", s->laddr, s->lifindex);
 }