Fix detection on OSX and make detection smarter.

- Fix lsif() on OSX.
- Make lsif() smarter and avoid non-broadcast and no AF_INET addresses.
- Don't run multiple interface detectors, run one at a time until one works.
- Factor out HAVE_IFADDRS_H code into a separate function into lsif.c with the other interface detection routines.
- Prefer HAVE_IFADDRS_H (random bias..)

lsif.c

@@ -28,6 +28,7 @@
 
 #include "serval.h"
 
+#include <assert.h>
 #include <errno.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -70,6 +71,8 @@
 */
 int scrapeProcNetRoute()
 {
+  if (debug & DEBUG_OVERLAYINTERFACES) INFO("called");
+
   FILE *f=fopen("/proc/net/route","r");
   if (!f) return fprintf(stderr,"Can't read from /proc/net/route\n");
 
@@ -101,22 +104,26 @@ int scrapeProcNetRoute()
 #endif
 
 #ifdef SIOCGIFCONF
-int lsif(void)
-{
-  char            buf[8192] = {0};
-  struct ifconf   ifc = {0};
-  struct ifreq   *ifr = NULL;
-  int             sck = 0;
-  int             nInterfaces = 0;
-  int             i = 0;
-  struct ifreq    *item;
-  struct sockaddr_in local,broadcast;
+
+/* Not present in Linux */
+#ifndef _SIZEOF_ADDR_IFREQ
+#define _SIZEOF_ADDR_IFREQ(x) sizeof(struct ifreq)
+#endif
+
+int
+lsif(void) {
+  char            buf[8192], addrtxt[INET_ADDRSTRLEN], bcasttxt[INET_ADDRSTRLEN];
+  struct ifconf   ifc;
+  int             sck, nInterfaces, ofs;
+  struct ifreq    *ifr;
+  struct sockaddr_in local, broadcast;
+
+  if (debug & DEBUG_OVERLAYINTERFACES) INFO("called");
 
   /* Get a socket handle. */
   sck = socket(PF_INET, SOCK_DGRAM, 0);
   if(sck < 0) {
-    fprintf(stderr,"Failed to gt socket handle to list addresses, errno=%d\n",
-	    errno);
+    WHY_perror("socket");
     return 1;
   }
  
@@ -124,31 +131,91 @@ int lsif(void)
   ifc.ifc_len = sizeof(buf);
   ifc.ifc_buf = buf;
   if(ioctl(sck, SIOCGIFCONF, &ifc) < 0) {
-    fprintf(stderr,"Failed to read interface list\n");
+    WHY_perror("ioctl(SIOCGIFCONF)");
     return 1;
   }
 
   /* Iterate through the list of interfaces. */
-  ifr = ifc.ifc_req;
-  nInterfaces = ifc.ifc_len / sizeof(struct ifreq); 
-  fprintf(stderr,"Examining %d interfaces\n",nInterfaces);
-  for(i = 0; i < nInterfaces; i++) {
-    item = &ifr[i];
-    
-    bcopy(&item->ifr_addr,&local,sizeof(local));      
+  nInterfaces = 0;
+  ofs = 0;
+  while (ofs < ifc.ifc_len) {
+    ifr = (struct ifreq *)(ifc.ifc_ifcu.ifcu_buf + ofs);
+    ofs += _SIZEOF_ADDR_IFREQ(*ifr);
 
-    /* get broadcast address */
-    if(ioctl(sck, SIOCGIFBRDADDR, item)== 0) {
-      bcopy(&item->ifr_broadaddr,&broadcast,sizeof(broadcast));
-    } else continue;
+    /* We're only interested in IPv4 addresses */
+    if (ifr->ifr_ifru.ifru_addr.sa_family != AF_INET) {
+      if (debug & DEBUG_OVERLAYINTERFACES) INFOF("Skipping non-AF_INET address on %s", ifr->ifr_name);
+      continue;
+    }
+  
+    /* Get interface flags */
+    if (ioctl(sck, SIOCGIFFLAGS, ifr) == -1)
+      FATAL_perror("ioctl(SIOCGIFFLAGS)");
 
-    printf("name=%s addr=%08x, broad=%08x\n",	   
-	   item->ifr_name,
-	   local.sin_addr,
-	   broadcast.sin_addr);
-    overlay_interface_register(item->ifr_name,local,broadcast);
+    /* Not broadcast? Not interested.. */
+    if ((ifr->ifr_ifru.ifru_flags & IFF_BROADCAST) == 0) {
+      if (debug & DEBUG_OVERLAYINTERFACES) INFOF("Skipping non-broadcast address on %s", ifr->ifr_name);
+      continue;
+    }
+      
+    /* Get broadcast address */
+    if (ioctl(sck, SIOCGIFBRDADDR, ifr, sizeof(*ifr)) == -1)
+      FATAL_perror("ioctl(SIOCGIFBRDADDR)");
+
+    bcopy(&ifr->ifr_ifru.ifru_addr, &local, sizeof(local));      
+    bcopy(&ifr->ifr_ifru.ifru_broadaddr, &broadcast ,sizeof(broadcast));
+
+    assert(inet_ntop(AF_INET, (const void *)&local.sin_addr, addrtxt, INET_ADDRSTRLEN) != NULL);
+    assert(inet_ntop(AF_INET, (const void *)&broadcast.sin_addr, bcasttxt, INET_ADDRSTRLEN) != NULL);
+      
+    if (debug & DEBUG_OVERLAYINTERFACES) INFOF("name=%s addr=%s, broad=%s\n",
+					     ifr->ifr_name,
+					     addrtxt, bcasttxt);
+    overlay_interface_register(ifr->ifr_name, local, broadcast);
+    nInterfaces++;
   }
+  
+  if (debug & DEBUG_OVERLAYINTERFACES) INFOF("Examined %d interface addresses\n", nInterfaces);
+
   close(sck); 
   return 0;
 }
+
 #endif
+
+#ifdef HAVE_IFADDRS_H
+int doifaddrs(void) {
+  struct ifaddrs *ifaddr,*ifa;
+  int family;
+  
+  if (debug & DEBUG_OVERLAYINTERFACES) INFOF("called");
+  
+  if (getifaddrs(&ifaddr) == -1)  {
+    WHY_perror("getifaddr()");
+    return WHY("getifaddrs() failed");
+  }
+
+  /* Check through actual network interfaces */
+  for (ifa=ifaddr;ifa!=NULL;ifa=ifa->ifa_next) {
+    family=ifa->ifa_addr->sa_family;
+    switch(family) {
+    case AF_INET: 
+      {
+	unsigned char *name=(unsigned char *)ifa->ifa_name;
+	struct sockaddr_in local=*(struct sockaddr_in *)ifa->ifa_addr;
+	struct sockaddr_in netmask=*(struct sockaddr_in *)ifa->ifa_netmask;
+	struct sockaddr_in broadcast=local;
+	broadcast.sin_addr.s_addr|=(~netmask.sin_addr.s_addr);
+	if (debug&DEBUG_OVERLAYINTERFACES) printf("%s: %08x %08x %08x\n",name,local.sin_addr.s_addr,netmask.sin_addr.s_addr,broadcast.sin_addr.s_addr);
+	overlay_interface_register(name,local,broadcast);
+
+	break;
+      }
+    }
+  }
+  freeifaddrs(ifaddr);
+
+  return 0;
+}
+#endif
+

overlay_interface.c

@@ -556,6 +556,8 @@ int overlay_interface_register(unsigned char *name,
 time_t overlay_last_interface_discover_time=0;
 int overlay_interface_discover()
 {
+  int have_route;
+  
   /* Don't waste too much time and effort on interface discovery,
      especially if we can't attach to a given interface for some reason. */
   if (overlay_last_interface_discover_time>time(0))
@@ -595,45 +597,27 @@ int overlay_interface_discover()
     }
     r=r->next;
   }
+  have_route = 1;
+  
+#ifdef HAVE_IFADDRS_H
+  if (have_route != 0)
+    have_route = doifaddrs();
+#endif
 
 #ifdef SIOCGIFCONF
-  lsif();
+  if (have_route != 0)
+    have_route = lsif();
 #endif
 
 #ifdef linux
-  scrapeProcNetRoute();
+  if (have_route != 0)
+    have_route = scrapeProcNetRoute();
 #endif
 
-#ifdef HAVE_IFADDRS_H
-  struct ifaddrs *ifaddr,*ifa;
-  int family;
+  if (have_route != 0) {
+    FATAL("Unable to get any routing information");
+  }
   
-  if (getifaddrs(&ifaddr) == -1)  {
-    WHY_perror("getifaddr()");
-    return WHY("getifaddrs() failed");
-  }
-
-  /* Check through actual network interfaces */
-  for (ifa=ifaddr;ifa!=NULL;ifa=ifa->ifa_next) {
-    family=ifa->ifa_addr->sa_family;
-    switch(family) {
-    case AF_INET: 
-      {
-	unsigned char *name=(unsigned char *)ifa->ifa_name;
-	struct sockaddr_in local=*(struct sockaddr_in *)ifa->ifa_addr;
-	struct sockaddr_in netmask=*(struct sockaddr_in *)ifa->ifa_netmask;
-	struct sockaddr_in broadcast=local;
-	broadcast.sin_addr.s_addr|=(~netmask.sin_addr.s_addr);
-	if (debug&DEBUG_OVERLAYINTERFACES) printf("%s: %08x %08x %08x\n",name,local.sin_addr.s_addr,netmask.sin_addr.s_addr,broadcast.sin_addr.s_addr);
-	overlay_interface_register(name,local,broadcast);
-
-	break;
-      }
-    }
-  }
-  freeifaddrs(ifaddr);
-#endif
-
   return 0;
 }
 

serval.h

@@ -623,10 +623,9 @@ typedef struct overlay_interface {
   int sequence_number;
   /* XXX need recent packet buffers to support the above */
 
-  /* Broadcast address and netmask, if known */
-  /* We really only case about distinct broadcast addresses on interfaces.
-     Also simplifies aliases on interfaces.
-     struct sockaddr_in local_address; */
+  /* Broadcast address and netmask, if known
+     We really only case about distinct broadcast addresses on interfaces.
+     Also simplifies aliases on interfaces. */
   struct sockaddr_in broadcast_address;
 
   /* Not necessarily the real MTU, but the largest frame size we are willing to TX on this interface.
@@ -1500,6 +1499,7 @@ int encodeAndDispatchRecordedAudio(int fd,int callSessionToken,
 				   int sampleBytes);
 int scrapeProcNetRoute();
 int lsif();
+int doifaddrs();
 int bufferAudioForPlayback(int codec,long long start_time,long long end_time,
 			   unsigned char *data,int dataLen);
 int startAudio();