diff options
Diffstat (limited to 'libc/inet/if_nametoindex.c')
| -rw-r--r-- | libc/inet/if_nametoindex.c | 171 |
1 files changed, 149 insertions, 22 deletions
diff --git a/libc/inet/if_nametoindex.c b/libc/inet/if_nametoindex.c index 40818aad9..a697419b6 100644 --- a/libc/inet/if_nametoindex.c +++ b/libc/inet/if_nametoindex.c @@ -1,40 +1,167 @@ -/* +/* Copyright (C) 1997,98,99,2000,02 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. * - * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>, - * The Silver Hammer Group, Ltd. + * 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. * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Library General Public - * License as published by the Free Software Foundation; either - * version 2 of the License, or (at your option) any later version. + * 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> */ + #define __FORCE_GLIBC #include <features.h> +#include <string.h> +#include <errno.h> #include <net/if.h> #include <sys/ioctl.h> #include <unistd.h> +#include <stdlib.h> -unsigned int if_nametoindex(const char* blub) { - struct ifreq ifr; - int fd; - char *tmp; - int len=sizeof(ifr.ifr_name); - +static int __opensock(void) +{ + int fd; #ifdef __UCLIBC_HAS_IPV6__ - fd=socket(AF_INET6,SOCK_DGRAM,0); - if (fd<0) + fd=socket(AF_INET6,SOCK_DGRAM,0); + if (fd<0) #endif /* __UCLIBC_HAS_IPV6__ */ - fd=socket(AF_INET,SOCK_DGRAM,0); + fd=socket(AF_INET,SOCK_DGRAM,0); + return(fd); +} + +unsigned int if_nametoindex(const char* ifname) +{ +#ifndef SIOCGIFINDEX + __set_errno (ENOSYS); + return 0; +#else + int fd; + struct ifreq ifr; - for (tmp=ifr.ifr_name; len>0; --len) { - if ((*tmp++ = *blub++)==0) break; + fd = __opensock(); + if (fd < 0) + return 0; + strncpy (ifr.ifr_name, ifname, sizeof (ifr.ifr_name)); + if (ioctl(fd,SIOCGIFINDEX,&ifr) < 0) { + int saved_errno = errno; + close(fd); + if (saved_errno == EINVAL) + __set_errno(ENOSYS); + return 0; + } + close(fd); + return ifr.ifr_ifindex; + +#endif /* SIOCGIFINDEX */ +} + +void if_freenameindex (struct if_nameindex *ifn) +{ + struct if_nameindex *ptr = ifn; + while (ptr->if_name || ptr->if_index) { + if (ptr->if_name) { + free (ptr->if_name); } + ++ptr; + } + free (ifn); +} + +struct if_nameindex * if_nameindex (void) +{ +#ifndef SIOCGIFINDEX + __set_errno (ENOSYS); + return NULL; +#else + int fd; + struct ifconf ifc; + unsigned int nifs, i; + int rq_len; + struct if_nameindex *idx = NULL; +# define RQ_IFS 4 + + fd = __opensock(); + if (fd < 0) + return 0; + + ifc.ifc_buf = NULL; - if (ioctl(fd,SIOCGIFINDEX,&ifr)==0) { - close(fd); - return ifr.ifr_ifindex; + /* Guess on the correct buffer size... */ + rq_len = RQ_IFS * sizeof (struct ifreq); + + /* Read all the interfaces out of the kernel. */ + do { + ifc.ifc_buf = realloc(ifc.ifc_buf, ifc.ifc_len = rq_len); + if (ifc.ifc_buf == NULL || ioctl(fd, SIOCGIFCONF, &ifc) < 0) { + close(fd); + return NULL; } + rq_len *= 2; + } 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(fd); - return 0; + __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(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(fd); + return idx; +#endif } + +char * if_indextoname (unsigned int ifindex, char *ifname) +{ + 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); + } + return result; +} + |