/* vi: set sw=4 ts=4: */ /* * iplink.c "ip link". * * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ //#include <sys/ioctl.h> //#include <sys/socket.h> #include <net/if.h> #include <net/if_packet.h> #include <netpacket/packet.h> #include <net/ethernet.h> #include "ip_common.h" /* #include "libbb.h" is inside */ #include "rt_names.h" #include "utils.h" /* taken from linux/sockios.h */ #define SIOCSIFNAME 0x8923 /* set interface name */ /* Exits on error */ static int get_ctl_fd(void) { int fd; fd = socket(PF_INET, SOCK_DGRAM, 0); if (fd >= 0) return fd; fd = socket(PF_PACKET, SOCK_DGRAM, 0); if (fd >= 0) return fd; return xsocket(PF_INET6, SOCK_DGRAM, 0); } /* Exits on error */ static void do_chflags(char *dev, uint32_t flags, uint32_t mask) { struct ifreq ifr; int fd; strncpy_IFNAMSIZ(ifr.ifr_name, dev); fd = get_ctl_fd(); xioctl(fd, SIOCGIFFLAGS, &ifr); if ((ifr.ifr_flags ^ flags) & mask) { ifr.ifr_flags &= ~mask; ifr.ifr_flags |= mask & flags; xioctl(fd, SIOCSIFFLAGS, &ifr); } close(fd); } /* Exits on error */ static void do_changename(char *dev, char *newdev) { struct ifreq ifr; int fd; strncpy_IFNAMSIZ(ifr.ifr_name, dev); strncpy_IFNAMSIZ(ifr.ifr_newname, newdev); fd = get_ctl_fd(); xioctl(fd, SIOCSIFNAME, &ifr); close(fd); } /* Exits on error */ static void set_qlen(char *dev, int qlen) { struct ifreq ifr; int s; s = get_ctl_fd(); memset(&ifr, 0, sizeof(ifr)); strncpy_IFNAMSIZ(ifr.ifr_name, dev); ifr.ifr_qlen = qlen; xioctl(s, SIOCSIFTXQLEN, &ifr); close(s); } /* Exits on error */ static void set_mtu(char *dev, int mtu) { struct ifreq ifr; int s; s = get_ctl_fd(); memset(&ifr, 0, sizeof(ifr)); strncpy_IFNAMSIZ(ifr.ifr_name, dev); ifr.ifr_mtu = mtu; xioctl(s, SIOCSIFMTU, &ifr); close(s); } /* Exits on error */ static int get_address(char *dev, int *htype) { struct ifreq ifr; struct sockaddr_ll me; socklen_t alen; int s; s = xsocket(PF_PACKET, SOCK_DGRAM, 0); memset(&ifr, 0, sizeof(ifr)); strncpy_IFNAMSIZ(ifr.ifr_name, dev); xioctl(s, SIOCGIFINDEX, &ifr); memset(&me, 0, sizeof(me)); me.sll_family = AF_PACKET; me.sll_ifindex = ifr.ifr_ifindex; me.sll_protocol = htons(ETH_P_LOOP); xbind(s, (struct sockaddr*)&me, sizeof(me)); alen = sizeof(me); getsockname(s, (struct sockaddr*)&me, &alen); //never happens: //if (getsockname(s, (struct sockaddr*)&me, &alen) == -1) // bb_perror_msg_and_die("getsockname"); close(s); *htype = me.sll_hatype; return me.sll_halen; } /* Exits on error */ static void parse_address(char *dev, int hatype, int halen, char *lla, struct ifreq *ifr) { int alen; memset(ifr, 0, sizeof(*ifr)); strncpy_IFNAMSIZ(ifr->ifr_name, dev); ifr->ifr_hwaddr.sa_family = hatype; alen = hatype == 1/*ARPHRD_ETHER*/ ? 14/*ETH_HLEN*/ : 19/*INFINIBAND_HLEN*/; alen = ll_addr_a2n((unsigned char *)(ifr->ifr_hwaddr.sa_data), alen, lla); if (alen < 0) exit(EXIT_FAILURE); if (alen != halen) { bb_error_msg_and_die("wrong address (%s) length: expected %d bytes", lla, halen); } } /* Exits on error */ static void set_address(struct ifreq *ifr, int brd) { int s; s = get_ctl_fd(); if (brd) xioctl(s, SIOCSIFHWBROADCAST, ifr); else xioctl(s, SIOCSIFHWADDR, ifr); close(s); } static void die_must_be_on_off(const char *msg) NORETURN; static void die_must_be_on_off(const char *msg) { bb_error_msg_and_die("argument of \"%s\" must be \"on\" or \"off\"", msg); } /* Return value becomes exitcode. It's okay to not return at all */ static int do_set(char **argv) { char *dev = NULL; uint32_t mask = 0; uint32_t flags = 0; int qlen = -1; int mtu = -1; char *newaddr = NULL; char *newbrd = NULL; struct ifreq ifr0, ifr1; char *newname = NULL; int htype, halen; static const char keywords[] ALIGN1 = "up\0""down\0""name\0""mtu\0""multicast\0" "arp\0""address\0""dev\0"; enum { ARG_up = 0, ARG_down, ARG_name, ARG_mtu, ARG_multicast, ARG_arp, ARG_addr, ARG_dev }; static const char str_on_off[] ALIGN1 = "on\0""off\0"; enum { PARM_on = 0, PARM_off }; smalluint key; while (*argv) { /* substring search ensures that e.g. "addr" and "address" * are both accepted */ key = index_in_substrings(keywords, *argv); if (key == ARG_up) { mask |= IFF_UP; flags |= IFF_UP; } if (key == ARG_down) { mask |= IFF_UP; flags &= ~IFF_UP; } if (key == ARG_name) { NEXT_ARG(); newname = *argv; } if (key == ARG_mtu) { NEXT_ARG(); if (mtu != -1) duparg("mtu", *argv); mtu = get_unsigned(*argv, "mtu"); } if (key == ARG_multicast) { int param; NEXT_ARG(); mask |= IFF_MULTICAST; param = index_in_strings(str_on_off, *argv); if (param < 0) die_must_be_on_off("multicast"); if (param == PARM_on) flags |= IFF_MULTICAST; else flags &= ~IFF_MULTICAST; } if (key == ARG_arp) { int param; NEXT_ARG(); mask |= IFF_NOARP; param = index_in_strings(str_on_off, *argv); if (param < 0) die_must_be_on_off("arp"); if (param == PARM_on) flags &= ~IFF_NOARP; else flags |= IFF_NOARP; } if (key == ARG_addr) { NEXT_ARG(); newaddr = *argv; } if (key >= ARG_dev) { if (key == ARG_dev) { NEXT_ARG(); } if (dev) duparg2("dev", *argv); dev = *argv; } argv++; } if (!dev) { bb_error_msg_and_die(bb_msg_requires_arg, "\"dev\""); } if (newaddr || newbrd) { halen = get_address(dev, &htype); if (newaddr) { parse_address(dev, htype, halen, newaddr, &ifr0); } if (newbrd) { parse_address(dev, htype, halen, newbrd, &ifr1); } } if (newname && strcmp(dev, newname)) { do_changename(dev, newname); dev = newname; } if (qlen != -1) { set_qlen(dev, qlen); } if (mtu != -1) { set_mtu(dev, mtu); } if (newaddr || newbrd) { if (newbrd) { set_address(&ifr1, 1); } if (newaddr) { set_address(&ifr0, 0); } } if (mask) do_chflags(dev, flags, mask); return 0; } static int ipaddr_list_link(char **argv) { preferred_family = AF_PACKET; return ipaddr_list_or_flush(argv, 0); } /* Return value becomes exitcode. It's okay to not return at all */ int do_iplink(char **argv) { static const char keywords[] ALIGN1 = "set\0""show\0""lst\0""list\0"; int key; if (!*argv) return ipaddr_list_link(argv); key = index_in_substrings(keywords, *argv); if (key < 0) bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name); argv++; if (key == 0) /* set */ return do_set(argv); /* show, lst, list */ return ipaddr_list_link(argv); }