[src/trunk]: src/usr.sbin/traceroute Don't use a static buffer for ifaddrs (a...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/adc59ef3b89c
branches:  trunk
changeset: 764895:adc59ef3b89c
user:      christos <christos%NetBSD.org@localhost>
date:      Wed May 11 00:38:28 2011 +0000

description:
Don't use a static buffer for ifaddrs (and not check for overflowing it!)
(speciallly if you are setuid!)

diffstat:

 usr.sbin/traceroute/ifaddrlist.c |  61 ++++++++++++++++++++++++---------------
 usr.sbin/traceroute/ifaddrlist.h |   6 +-
 2 files changed, 40 insertions(+), 27 deletions(-)

diffs (116 lines):

diff -r 554b577d8589 -r adc59ef3b89c usr.sbin/traceroute/ifaddrlist.c
--- a/usr.sbin/traceroute/ifaddrlist.c  Wed May 11 00:38:03 2011 +0000
+++ b/usr.sbin/traceroute/ifaddrlist.c  Wed May 11 00:38:28 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ifaddrlist.c,v 1.8 2011/05/10 01:52:49 christos Exp $  */
+/*     $NetBSD: ifaddrlist.c,v 1.9 2011/05/11 00:38:28 christos Exp $  */
 
 /*
  * Copyright (c) 1997
@@ -39,7 +39,7 @@
 static const char rcsid[] =
     "@(#) Header: ifaddrlist.c,v 1.2 97/04/22 13:31:05 leres Exp  (LBL)";
 #else
-__RCSID("$NetBSD: ifaddrlist.c,v 1.8 2011/05/10 01:52:49 christos Exp $");
+__RCSID("$NetBSD: ifaddrlist.c,v 1.9 2011/05/11 00:38:28 christos Exp $");
 #endif
 #endif
 
@@ -82,29 +82,23 @@
 #define ISLOOPBACK(p) (strcmp((p)->ifa_name, "lo0") == 0)
 #endif
 
-#define MAX_IPADDR 256
-
 /*
  * Return the interface list
  */
-int
-ifaddrlist(struct ifaddrlist **ipaddrp, char *errbuf, int buflen)
+ssize_t
+ifaddrlist(struct ifaddrlist **ipaddrp, char *errbuf, size_t buflen)
 {
-       int nipaddr;
        struct sockaddr_in *sin;
-       struct ifaddrs *ifap, *ifa;
-       struct ifaddrlist *al;
-       static struct ifaddrlist xifaddrlist[MAX_IPADDR];
+       struct ifaddrs *ifap = NULL, *ifa;
+       struct ifaddrlist *al = NULL, *nal;
+       size_t i = 0, maxal = 10;
 
-       al = xifaddrlist;
-       nipaddr = 0;
+       if (getifaddrs(&ifap) != 0)
+               goto out;
 
-       if (getifaddrs(&ifap) != 0) {
-               (void)snprintf(errbuf, buflen, "getifaddrs: %s",
-                   strerror(errno));
-               return (-1);
-       }
-
+       if ((al = malloc(maxal * sizeof(*al))) == NULL)
+               goto out;
+               
        for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
                if (ifa->ifa_addr->sa_family != AF_INET)
                        continue;
@@ -121,12 +115,31 @@
                        if (ntohl(sin->sin_addr.s_addr) == INADDR_LOOPBACK)
                                continue;
 
-               al->addr = sin->sin_addr.s_addr;
-               al->device = strdup(ifa->ifa_name);
-               ++al;
-               ++nipaddr;
+               if (i == maxal) {
+                       maxal <<= 1;
+                       if ((nal = realloc(al, maxal * sizeof(*al))) == NULL)
+                               goto out;
+                       al = nal;
+               }
+
+               al[i].addr = sin->sin_addr.s_addr;
+               if ((al[i].device = strdup(ifa->ifa_name)) == NULL)
+                       goto out;
+               i++;
        }
-       *ipaddrp = xifaddrlist;
+       if ((nal = realloc(al, i * sizeof(*al))) == NULL)
+               goto out;
        freeifaddrs(ifap);
-       return (nipaddr);
+       *ipaddrp = nal;
+       return (ssize_t)i;
+out:
+       if (ifap)
+               freeifaddrs(ifap);
+       if (al) {
+               while (i > 0)
+                       free(al[--i].device);
+               free(al);
+       }
+       (void)snprintf(errbuf, buflen, "%s: %s", __func__, strerror(errno));
+       return -1;
 }
diff -r 554b577d8589 -r adc59ef3b89c usr.sbin/traceroute/ifaddrlist.h
--- a/usr.sbin/traceroute/ifaddrlist.h  Wed May 11 00:38:03 2011 +0000
+++ b/usr.sbin/traceroute/ifaddrlist.h  Wed May 11 00:38:28 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ifaddrlist.h,v 1.2 1998/07/04 20:47:24 mrg Exp $       */
+/*     $NetBSD: ifaddrlist.h,v 1.3 2011/05/11 00:38:28 christos Exp $  */
 
 /*
  * Copyright (c) 1997
@@ -24,8 +24,8 @@
  */
 
 struct ifaddrlist {
-       u_int32_t addr;
+       uint32_t addr;
        char *device;
 };
 
-int    ifaddrlist(struct ifaddrlist **, char *, int);
+ssize_t        ifaddrlist(struct ifaddrlist **, char *, size_t);