o SIOCGIFCONF -> getifaddrs(3) conversion. As a side effect fix

bin/95041: subnet mask mismatch.

PR:		bin/95041
Obtained from:	NetBSD
Tested by:	Hans Lambermont
MFC after:	2 months

2 files changed, 44 insertions, 97 deletions

diff --git a/usr.sbin/mrouted/cfparse.y b/usr.sbin/mrouted/cfparse.y
index 1827f6a..9ab1f62 100644
--- a/usr.sbin/mrouted/cfparse.y
+++ b/usr.sbin/mrouted/cfparse.y
@@ -15,6 +15,7 @@
 #endif
 #include "defs.h"
 #include <netdb.h>
+#include <ifaddrs.h>
 
 /*
  * Local function declarations
@@ -25,7 +26,7 @@ static void		yyerror __P((char *s));
 static char *		next_word __P((void));
 static int		yylex __P((void));
 static u_int32		valid_if __P((char *s));
-static struct ifreq *	ifconfaddr __P((struct ifconf *ifcp, u_int32 a));
+static const char *	ifconfaddr(u_int32_t a);
 int			yyparse __P((void));
 
 static FILE *f;
@@ -128,15 +129,14 @@ stmt	: error
 					}
 		ifmods
 	| TUNNEL interface addrname	{
-
-			struct ifreq *ifr;
+			const char *ifname;
 			struct ifreq ffr;
 			vifi_t vifi;
 
 			order++;
 
-			ifr = ifconfaddr(&ifc, $2);
-			if (ifr == 0)
+			ifname = ifconfaddr($2);
+			if (ifname == 0)
 			    fatal("Tunnel local address %s is not mine",
 				inet_fmt($2, s1));
 
@@ -145,7 +145,7 @@ stmt	: error
 			    fatal("Tunnel local address %s is a loopback address",
 				inet_fmt($2, s1));
 
-			if (ifconfaddr(&ifc, $3) != 0)
+			if (ifconfaddr($3) != 0)
 			    fatal("Tunnel remote address %s is one of mine",
 				inet_fmt($3, s1));
 
@@ -165,7 +165,7 @@ stmt	: error
 			if (numvifs == MAXVIFS)
 			    fatal("too many vifs");
 
-			strncpy(ffr.ifr_name, ifr->ifr_name, IFNAMSIZ);
+			strlcpy(ffr.ifr_name, ifname, sizeof(ffr.ifr_name));
 			if (ioctl(udp_socket, SIOCGIFFLAGS, (char *)&ffr)<0)
 			    fatal("ioctl SIOCGIFFLAGS on %s", ffr.ifr_name);
 
@@ -176,8 +176,7 @@ stmt	: error
 			v->uv_lcl_addr	= $2;
 			v->uv_rmt_addr	= $3;
 			v->uv_dst_addr	= $3;
-			strncpy(v->uv_name, ffr.ifr_name, IFNAMSIZ);
-			v->uv_name[IFNAMSIZ-1]='\0';
+			strlcpy(v->uv_name, ffr.ifr_name, sizeof(v->uv_name));
 
 			if (!(ffr.ifr_flags & IFF_UP)) {
 			    v->uv_flags |= VIFF_DOWN;
@@ -905,28 +904,24 @@ char *s;
 	return 0;
 }
 
-static struct ifreq *
-ifconfaddr(ifcp, a)
-    struct ifconf *ifcp;
-    u_int32 a;
+static const char *
+ifconfaddr(u_int32_t a)
 {
-    int n;
-    struct ifreq *ifrp = (struct ifreq *)ifcp->ifc_buf;
-    struct ifreq *ifend = (struct ifreq *)((char *)ifrp + ifcp->ifc_len);
-
-    while (ifrp < ifend) {
-	    if (ifrp->ifr_addr.sa_family == AF_INET &&
-		((struct sockaddr_in *)&ifrp->ifr_addr)->sin_addr.s_addr == a)
-		    return (ifrp);
-#ifdef HAVE_SA_LEN
-		n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
-		if (n < sizeof(*ifrp))
-			++ifrp;
-		else
-			ifrp = (struct ifreq *)((char *)ifrp + n);
-#else
-		++ifrp;
-#endif
+    static char ifname[IFNAMSIZ];
+    struct ifaddrs *ifap, *ifa;
+
+    if (getifaddrs(&ifap) != 0)
+	return (NULL);
+
+    for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
+	if (ifa->ifa_addr->sa_family == AF_INET &&
+	    ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr == a) {
+	    strlcpy(ifname, ifa->ifa_name, sizeof(ifname));
+	    freeifaddrs(ifap);
+	    return (ifname);
+	}
     }
-    return (0);
+
+    freeifaddrs(ifap);
+    return (NULL);
 }
diff --git a/usr.sbin/mrouted/config.c b/usr.sbin/mrouted/config.c
index 9ca6f88..9f83fb7 100644
--- a/usr.sbin/mrouted/config.c
+++ b/usr.sbin/mrouted/config.c
@@ -16,9 +16,7 @@ static const char rcsid[] =
 #endif /* not lint */
 
 #include "defs.h"
-
-
-struct ifconf ifc;
+#include <ifaddrs.h>
 
 /*
  * Query the kernel to find network interfaces that are multicast-capable
@@ -27,94 +25,47 @@ struct ifconf ifc;
 void
 config_vifs_from_kernel()
 {
-    struct ifreq *ifrp, *ifend;
+    struct ifaddrs *ifa, *ifap;
     register struct uvif *v;
     register vifi_t vifi;
-    int n;
     u_int32 addr, mask, subnet;
     int flags;
-    int num_ifreq = 32;
 
-    ifc.ifc_len = num_ifreq * sizeof(struct ifreq);
-    ifc.ifc_buf = malloc(ifc.ifc_len);
-    while (ifc.ifc_buf) {
-	if (ioctl(udp_socket, SIOCGIFCONF, (char *)&ifc) < 0)
-	    log(LOG_ERR, errno, "ioctl SIOCGIFCONF");
-
-	/*
-	 * If the buffer was large enough to hold all the addresses
-	 * then break out, otherwise increase the buffer size and
-	 * try again.
-	 *
-	 * The only way to know that we definitely had enough space
-	 * is to know that there was enough space for at least one
-	 * more struct ifreq. ???
-	 */
-	if ((num_ifreq * sizeof(struct ifreq)) >=
-	     ifc.ifc_len + sizeof(struct ifreq))
-	     break;
-
-	num_ifreq *= 2;
-	ifc.ifc_len = num_ifreq * sizeof(struct ifreq);
-	ifc.ifc_buf = realloc(ifc.ifc_buf, ifc.ifc_len);
-    }
-    if (ifc.ifc_buf == NULL)
-	log(LOG_ERR, 0, "config_vifs_from_kernel: ran out of memory");
-
-    ifrp = (struct ifreq *)ifc.ifc_buf;
-    ifend = (struct ifreq *)(ifc.ifc_buf + ifc.ifc_len);
+    if (getifaddrs(&ifap) < 0)
+	log(LOG_ERR, errno, "getifaddrs");
     /*
      * Loop through all of the interfaces.
      */
-    for (; ifrp < ifend; ifrp = (struct ifreq *)((char *)ifrp + n)) {
-	struct ifreq ifr;
-#ifdef HAVE_SA_LEN
-	n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
-	if (n < sizeof(*ifrp))
-	    n = sizeof(*ifrp);
-#else
-	n = sizeof(*ifrp);
-#endif
+    for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
 	/*
 	 * Ignore any interface for an address family other than IP.
 	 */
-	if (ifrp->ifr_addr.sa_family != AF_INET)
+	if (ifa->ifa_addr->sa_family != AF_INET)
 	    continue;
 
-	addr = ((struct sockaddr_in *)&ifrp->ifr_addr)->sin_addr.s_addr;
-
-	/*
-	 * Need a template to preserve address info that is
-	 * used below to locate the next entry.  (Otherwise,
-	 * SIOCGIFFLAGS stomps over it because the requests
-	 * are returned in a union.)
-	 */
-	bcopy(ifrp->ifr_name, ifr.ifr_name, sizeof(ifr.ifr_name));
+	addr = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
 
 	/*
 	 * Ignore loopback interfaces and interfaces that do not support
 	 * multicast.
 	 */
-	if (ioctl(udp_socket, SIOCGIFFLAGS, (char *)&ifr) < 0)
-	    log(LOG_ERR, errno, "ioctl SIOCGIFFLAGS for %s", ifr.ifr_name);
-	flags = ifr.ifr_flags;
-	if ((flags & (IFF_LOOPBACK|IFF_MULTICAST)) != IFF_MULTICAST) continue;
+	flags = ifa->ifa_flags;
+	if ((flags & (IFF_LOOPBACK|IFF_MULTICAST)) != IFF_MULTICAST)
+	    continue;
 
 	/*
 	 * Ignore any interface whose address and mask do not define a
 	 * valid subnet number, or whose address is of the form {subnet,0}
 	 * or {subnet,-1}.
 	 */
-	if (ioctl(udp_socket, SIOCGIFNETMASK, (char *)&ifr) < 0)
-	    log(LOG_ERR, errno, "ioctl SIOCGIFNETMASK for %s", ifr.ifr_name);
-	mask = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr;
+	mask = ((struct sockaddr_in *)ifa->ifa_netmask)->sin_addr.s_addr;
 	subnet = addr & mask;
 	if (!inet_valid_subnet(subnet, mask) ||
 	    addr == subnet ||
 	    addr == (subnet | ~mask)) {
 	    log(LOG_WARNING, 0,
 		"ignoring %s, has invalid address (%s) and/or mask (%s)",
-		ifr.ifr_name, inet_fmt(addr, s1), inet_fmt(mask, s2));
+		ifa->ifa_name, inet_fmt(addr, s1), inet_fmt(mask, s2));
 	    continue;
 	}
 
@@ -123,7 +74,7 @@ config_vifs_from_kernel()
 	 * one already installed in the uvifs array.
 	 */
 	for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
-	    if (strcmp(v->uv_name, ifr.ifr_name) == 0) {
+	    if (strcmp(v->uv_name, ifa->ifa_name) == 0) {
 		log(LOG_DEBUG, 0, "skipping %s (%s on subnet %s) (alias for vif#%u?)",
 			v->uv_name, inet_fmt(addr, s1),
 			inet_fmts(subnet, mask, s2), vifi);
@@ -132,7 +83,7 @@ config_vifs_from_kernel()
 	    if ((addr & v->uv_subnetmask) == v->uv_subnet ||
 		(v->uv_subnet & mask) == subnet) {
 		log(LOG_WARNING, 0, "ignoring %s, same subnet as %s",
-					ifr.ifr_name, v->uv_name);
+		    ifa->ifa_name, v->uv_name);
 		break;
 	    }
 	}
@@ -142,7 +93,7 @@ config_vifs_from_kernel()
 	 * If there is room in the uvifs array, install this interface.
 	 */
 	if (numvifs == MAXVIFS) {
-	    log(LOG_WARNING, 0, "too many vifs, ignoring %s", ifr.ifr_name);
+	    log(LOG_WARNING, 0, "too many vifs, ignoring %s", ifa->ifa_name);
 	    continue;
 	}
 	v  = &uvifs[numvifs];
@@ -151,8 +102,7 @@ config_vifs_from_kernel()
 	v->uv_subnet      = subnet;
 	v->uv_subnetmask  = mask;
 	v->uv_subnetbcast = subnet | ~mask;
-	strncpy(v->uv_name, ifr.ifr_name, IFNAMSIZ);
-	v->uv_name[IFNAMSIZ-1] = '\0';
+	strlcpy(v->uv_name, ifa->ifa_name, sizeof(v->uv_name));
 
 	if (flags & IFF_POINTOPOINT)
 	    v->uv_flags |= VIFF_REXMIT_PRUNES;
@@ -172,4 +122,6 @@ config_vifs_from_kernel()
 	    vifs_down = TRUE;
 	}
     }
+
+    freeifaddrs(ifap);
 }