diff options
Diffstat (limited to 'util.c')
| -rw-r--r-- | util.c | 47 |
1 files changed, 33 insertions, 14 deletions
@@ -1,7 +1,7 @@ /* util.c * Utility routines * - * $Id: util.c,v 1.41 2000/08/11 13:34:53 deniel Exp $ + * $Id: util.c,v 1.42 2000/08/31 11:12:19 girlich Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs <gerald@zing.org> @@ -508,6 +508,8 @@ get_interface_list(int *err, char *err_str) int sock = socket(AF_INET, SOCK_DGRAM, 0); struct search_user_data user_data; pcap_t *pch; + int len, lastlen; + char *buf; if (sock < 0) { sprintf(err_str, "Error opening socket: %s", @@ -516,19 +518,36 @@ get_interface_list(int *err, char *err_str) } /* - * Since we have to grab the interface list all at once, we'll - * make plenty of room. + * This code came from: W. Richard Stevens: "UNIX Network Programming", + * Networking APIs: Sockets and XTI, Vol 1, page 434. */ - ifc.ifc_len = 1024 * sizeof(struct ifreq); - ifc.ifc_buf = malloc(ifc.ifc_len); - - if (ioctl(sock, SIOCGIFCONF, &ifc) < 0 || - ifc.ifc_len < sizeof(struct ifreq)) { - sprintf(err_str, "SIOCGIFCONF error getting list of interfaces: %s", - strerror(errno)); - goto fail; - } - + lastlen = 0; + len = 100 * sizeof(struct ifreq); + for ( ; ; ) { + buf = g_malloc(len); + ifc.ifc_len = len; + ifc.ifc_buf = buf; + memset (buf, 0, len); + if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) { + if (errno != EINVAL || lastlen != 0) { + sprintf(err_str, + "SIOCGIFCONF ioctl error getting list of interfaces: %s", + strerror(errno)); + goto fail; + } + } else { + if (ifc.ifc_len < sizeof(struct ifreq)) { + sprintf(err_str, + "SIOCGIFCONF ioctl gave too small return buffer"); + goto fail; + } + if (ifc.ifc_len == lastlen) + break; /* success, len has not changed */ + lastlen = ifc.ifc_len; + } + len += 10 * sizeof(struct ifreq); /* increment */ + g_free(buf); + } ifr = (struct ifreq *) ifc.ifc_req; last = (struct ifreq *) ((char *) ifr + ifc.ifc_len); while (ifr < last) { @@ -629,7 +648,7 @@ fail: g_list_foreach(il, free_if_cb, NULL); g_list_free(il); } - free(ifc.ifc_buf); + g_free(ifc.ifc_buf); close(sock); *err = CANT_GET_INTERFACE_LIST; return NULL; |