/* Copyright (C) 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. Reworked Dec 2002 by Erik Andersen <andersen@codepoet.org> */ #include <string.h> #include <alloca.h> #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <net/if.h> #include <sys/socket.h> #include <sys/ioctl.h> #include <not-cancel.h> #include "netlinkaccess.h" extern int __opensock(void) attribute_hidden; unsigned int if_nametoindex(const char* ifname) { #ifndef SIOCGIFINDEX __set_errno (ENOSYS); return 0; #else struct ifreq ifr; int fd = __opensock(); if (fd < 0) return 0; strncpy (ifr.ifr_name, ifname, sizeof (ifr.ifr_name)); if (ioctl (fd, SIOCGIFINDEX, &ifr) < 0) { /* close never fails here, fd is just a unconnected socket. *int saved_errno = errno; */ close_not_cancel_no_status(fd); /*if (saved_errno == EINVAL) * __set_errno(ENOSYS); */ return 0; } close_not_cancel_no_status(fd); return ifr.ifr_ifindex; #endif } libc_hidden_def(if_nametoindex) void if_freenameindex (struct if_nameindex *ifn) { struct if_nameindex *ptr = ifn; while (ptr->if_name || ptr->if_index) { free (ptr->if_name); ++ptr; } free (ifn); } libc_hidden_def(if_freenameindex) #if !__ASSUME_NETLINK_SUPPORT struct if_nameindex * if_nameindex (void) { #ifndef SIOCGIFINDEX __set_errno (ENOSYS); return NULL; #else int fd = __opensock (); struct ifconf ifc; unsigned int nifs, i; int rq_len; struct if_nameindex *idx = NULL; # define RQ_IFS 4 if (fd < 0) return NULL; ifc.ifc_buf = NULL; /* Guess on the correct buffer size... */ rq_len = RQ_IFS * sizeof (struct ifreq); /* Read all the interfaces out of the kernel. */ /* Note: alloca's in this loop are diff from glibc because it's smaller */ do { ifc.ifc_buf = extend_alloca (ifc.ifc_buf, rq_len, 2 * rq_len); ifc.ifc_len = rq_len; if (ioctl (fd, SIOCGIFCONF, &ifc) < 0) { close_not_cancel_no_status (fd); return NULL; } } while (ifc.ifc_len == rq_len); nifs = ifc.ifc_len / sizeof(struct ifreq); idx = malloc ((nifs + 1) * sizeof (struct if_nameindex)); if (idx == NULL) { close_not_cancel_no_status (fd); __set_errno(ENOBUFS); return NULL; } for (i = 0; i < nifs; ++i) { struct ifreq *ifr = &ifc.ifc_req[i]; idx[i].if_name = strdup (ifr->ifr_name); if (idx[i].if_name == NULL || ioctl (fd, SIOCGIFINDEX, ifr) < 0) { int saved_errno = errno; unsigned int j; for (j = 0; j < i; ++j) free (idx[j].if_name); free(idx); close_not_cancel_no_status (fd); if (saved_errno == EINVAL) saved_errno = ENOSYS; else if (saved_errno == ENOMEM) saved_errno = ENOBUFS; __set_errno (saved_errno); return NULL; } idx[i].if_index = ifr->ifr_ifindex; } idx[i].if_index = 0; idx[i].if_name = NULL; close_not_cancel_no_status (fd); return idx; #endif } #else struct if_nameindex * if_nameindex (void) { unsigned int nifs = 0; struct netlink_handle nh = { 0, 0, 0, NULL, NULL }; struct if_nameindex *idx = NULL; struct netlink_res *nlp; if (__netlink_open (&nh) < 0) return NULL; /* Tell the kernel that we wish to get a list of all active interfaces. Collect all data for every interface. */ if (__netlink_request (&nh, RTM_GETLINK) < 0) goto exit_free; /* Count the interfaces. */ for (nlp = nh.nlm_list; nlp; nlp = nlp->next) { struct nlmsghdr *nlh; size_t size = nlp->size; if (nlp->nlh == NULL) continue; /* Walk through all entries we got from the kernel and look, which message type they contain. */ for (nlh = nlp->nlh; NLMSG_OK (nlh, size); nlh = NLMSG_NEXT (nlh, size)) { /* Check if the message is what we want. */ if ((pid_t) nlh->nlmsg_pid != nh.pid || nlh->nlmsg_seq != nlp->seq) continue; if (nlh->nlmsg_type == NLMSG_DONE) break; /* ok */ if (nlh->nlmsg_type == RTM_NEWLINK) ++nifs; } } idx = malloc ((nifs + 1) * sizeof (struct if_nameindex)); if (idx == NULL) { nomem: __set_errno (ENOBUFS); goto exit_free; } /* Add the interfaces. */ nifs = 0; for (nlp = nh.nlm_list; nlp; nlp = nlp->next) { struct nlmsghdr *nlh; size_t size = nlp->size; if (nlp->nlh == NULL) continue; /* Walk through all entries we got from the kernel and look, which message type they contain. */ for (nlh = nlp->nlh; NLMSG_OK (nlh, size); nlh = NLMSG_NEXT (nlh, size)) { /* Check if the message is what we want. */ if ((pid_t) nlh->nlmsg_pid != nh.pid || nlh->nlmsg_seq != nlp->seq) continue; if (nlh->nlmsg_type == NLMSG_DONE) break; /* ok */ if (nlh->nlmsg_type == RTM_NEWLINK) { struct ifinfomsg *ifim = (struct ifinfomsg *) NLMSG_DATA (nlh); struct rtattr *rta = IFLA_RTA (ifim); size_t rtasize = IFLA_PAYLOAD (nlh); idx[nifs].if_index = ifim->ifi_index; while (RTA_OK (rta, rtasize)) { char *rta_data = RTA_DATA (rta); size_t rta_payload = RTA_PAYLOAD (rta); if (rta->rta_type == IFLA_IFNAME) { idx[nifs].if_name = strndup (rta_data, rta_payload); if (idx[nifs].if_name == NULL) { idx[nifs].if_index = 0; if_freenameindex (idx); idx = NULL; goto nomem; } break; } rta = RTA_NEXT (rta, rtasize); } ++nifs; } } } idx[nifs].if_index = 0; idx[nifs].if_name = NULL; exit_free: __netlink_free_handle (&nh); __netlink_close (&nh); return idx; } #endif libc_hidden_def(if_nameindex) char * if_indextoname (unsigned int ifindex, char *ifname) { #if !defined SIOCGIFINDEX __set_errno (ENOSYS); return NULL; #else # ifdef SIOCGIFNAME /* Use ioctl to avoid searching the list. */ struct ifreq ifr; int fd; fd = __opensock (); if (fd < 0) return NULL; ifr.ifr_ifindex = ifindex; if (ioctl (fd, SIOCGIFNAME, &ifr) < 0) { int serrno = errno; close_not_cancel_no_status (fd); if (serrno == ENODEV) /* POSIX requires ENXIO. */ serrno = ENXIO; __set_errno (serrno); return NULL; } close_not_cancel_no_status (fd); return strncpy (ifname, ifr.ifr_name, IFNAMSIZ); # else struct if_nameindex *idx; struct if_nameindex *p; char *result = NULL; idx = if_nameindex(); if (idx != NULL) { for (p = idx; p->if_index || p->if_name; ++p) if (p->if_index == ifindex) { result = strncpy (ifname, p->if_name, IFNAMSIZ); break; } if_freenameindex (idx); if (result == NULL) __set_errno (ENXIO); } return result; # endif #endif }