/* * %%% copyright-cmetz-98-bsd * Copyright (c) 1998-1999, Craig Metz, All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Craig Metz and * by other contributors. * 4. Neither the name of the author nor the names of contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include unsigned int if_nametoindex(const char *name) { int i, fd = -1, extra, len = 0; struct ifconf ifconf; char lastname[IFNAMSIZ], *thisname, *inbuf; unsigned int index = 0; struct sockaddr *sa; void *p; ifconf.ifc_buf = 0; if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) goto ret; /* * Try ifc_len == 0 hack first, to get the actual length. * If that fails, revert to a loop which grows the ifc_buf * until it is sufficiently large. */ extra = sizeof(struct ifreq); while (1) { ifconf.ifc_len = len; if (ioctl(fd, SIOCGIFCONF, (void *) &ifconf) == -1 && ifconf.ifc_buf) goto ret; if (ifconf.ifc_buf && ifconf.ifc_len + extra < len) break; if (ifconf.ifc_buf) { if (len == 0) len = 4096; ifconf.ifc_len = len *= 2; } else { len = ifconf.ifc_len; extra = 0; } inbuf = realloc(ifconf.ifc_buf, ifconf.ifc_len); if (inbuf == NULL) goto ret; ifconf.ifc_buf = inbuf; } i = 0; p = ifconf.ifc_buf; len = ifconf.ifc_len; lastname[0] = 0; lastname[sizeof(lastname)-1] = 0; while (len > 0) { if (len < IFNAMSIZ + sizeof(struct sockaddr)) goto ret; thisname = p; if (strncmp(lastname, p, IFNAMSIZ)) { if (!strcmp(lastname, name)) { index = i; goto ret; } memcpy(lastname, thisname, IFNAMSIZ); i++; } len -= IFNAMSIZ; p += IFNAMSIZ; sa = (struct sockaddr *)p; if (!strncmp(thisname, name, IFNAMSIZ) && sa->sa_family == AF_LINK) { struct sockaddr_dl *sd = p; index = sd->sdl_index; goto ret; } if (len < sa->sa_len) goto ret; len -= sa->sa_len; p += sa->sa_len; } if (!strcmp(lastname, name)) index = i; ret: if (fd != -1) close(fd); if (ifconf.ifc_buf) free(ifconf.ifc_buf); return index; }