diff options
Diffstat (limited to 'sysdeps/gnu')
| -rw-r--r-- | sysdeps/gnu/ifaddrs.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/sysdeps/gnu/ifaddrs.c b/sysdeps/gnu/ifaddrs.c new file mode 100644 index 0000000000..e0a5b424f0 --- /dev/null +++ b/sysdeps/gnu/ifaddrs.c @@ -0,0 +1,147 @@ +/* getifaddrs -- get names and addresses of all network interfaces + Copyright (C) 2002 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. */ + +#include <ifaddrs.h> +#include <net/if.h> +#include <sys/socket.h> +#include <sys/ioctl.h> +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <netinet/in.h> + +#include "ifreq.h" + +/* Create a linked list of `struct ifaddrs' structures, one for each + network interface on the host machine. If successful, store the + list in *IFAP and return 0. On errors, return -1 and set `errno'. */ +int +getifaddrs (struct ifaddrs **ifap) +{ + /* This implementation handles only IPv4 interfaces. + The various ioctls below will only work on an AF_INET socket. + Some different mechanism entirely must be used for IPv6. */ + int fd = __socket (AF_INET, SOCK_DGRAM, 0); + struct ifreq *ifreqs; + int nifs, i; + + if (fd < 0) + return -1; + + __ifreq (&ifreqs, &nifs, fd); + if (ifreqs == NULL) /* XXX doesn't distinguish error vs none */ + { + __close (fd); + return -1; + } + + /* Now we have the list of interfaces and each one's address. + Put it into the expected format and fill in the remaining details. */ + if (nifs == 0) + *ifap = NULL; + else + { + struct + { + struct ifaddrs ia; + struct sockaddr addr, netmask, broadaddr; + char name[IF_NAMESIZE]; + } *storage; + + storage = malloc (nifs * sizeof storage[0]); + if (storage == NULL) + { + __close (fd); + __if_freereq (ifreqs, nifs); + return -1; + } + + i = 0; + do + { + struct ifreq *const ifr = &ifreqs[i]; + + /* Fill in all pointers to the storage we've already allocated. */ + storage[i].ia.ifa_next = &storage[i + 1].ia; + storage[i].ia.ifa_addr = &storage[i].addr; + storage[i].ia.ifa_netmask = &storage[i].netmask; + storage[i].ia.ifa_broadaddr = &storage[i].broadaddr; /* & dstaddr */ + + /* Now copy the information we already have from SIOCGIFCONF. */ + storage[i].ia.ifa_name = strncpy (storage[i].name, ifr->ifr_name, + sizeof storage[i].name); + storage[i].addr = ifr->ifr_addr; + + /* The SIOCGIFCONF call filled in only the name and address. + Now we must also ask for the other information we need. */ + + if (__ioctl (fd, SIOCGIFFLAGS, ifr) < 0) + break; + storage[i].ia.ifa_flags = ifr->ifr_flags; + + ifr->ifr_addr = storage[i].addr; + if (__ioctl (fd, SIOCGIFNETMASK, ifr) < 0) + break; + storage[i].netmask = ifr->ifr_netmask; + + if (ifr->ifr_flags & IFF_BROADCAST) + { + ifr->ifr_addr = storage[i].addr; + if (__ioctl (fd, SIOCGIFBRDADDR, ifr) < 0) + break; + storage[i].broadaddr = ifr->ifr_broadaddr; + } + else if (ifr->ifr_flags & IFF_POINTOPOINT) + { + ifr->ifr_addr = storage[i].addr; + if (__ioctl (fd, SIOCGIFDSTADDR, ifr) < 0) + break; + storage[i].broadaddr = ifr->ifr_dstaddr; + } + else + /* Just 'cause. */ + memset (&storage[i].broadaddr, 0, sizeof storage[i].broadaddr); + + storage[i].ia.ifa_data = NULL; /* Nothing here for now. */ + + } while (++i < nifs); + if (i < nifs) /* Broke out early on error. */ + { + __close (fd); + free (storage); + __if_freereq (ifreqs, nifs); + return -1; + } + storage[i - 1].ia.ifa_next = NULL; + + *ifap = &storage[0].ia; + + __close (fd); + __if_freereq (ifreqs, nifs); + } + + return 0; +} + +void +freeifaddrs (struct ifaddrs *ifa) +{ + free (ifa); +} |