| /* |
| * iptunnel.c "ip tuntap" |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Authors: David Woodhouse <David.Woodhouse@intel.com> |
| * |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| #include <arpa/inet.h> |
| #include <sys/ioctl.h> |
| #include <linux/if.h> |
| #include <linux/if_tun.h> |
| #include <pwd.h> |
| #include <grp.h> |
| #include <fcntl.h> |
| #include <dirent.h> |
| #include <errno.h> |
| |
| #include "rt_names.h" |
| #include "utils.h" |
| #include "ip_common.h" |
| |
| #define TUNDEV "/dev/net/tun" |
| |
| static void usage(void) __attribute__((noreturn)); |
| |
| static void usage(void) |
| { |
| fprintf(stderr, "Usage: ip tuntap { add | del | show | list | lst | help } [ dev PHYS_DEV ] \n"); |
| fprintf(stderr, " [ mode { tun | tap } ] [ user USER ] [ group GROUP ]\n"); |
| fprintf(stderr, " [ one_queue ] [ pi ] [ vnet_hdr ] [ multi_queue ]\n"); |
| fprintf(stderr, "\n"); |
| fprintf(stderr, "Where: USER := { STRING | NUMBER }\n"); |
| fprintf(stderr, " GROUP := { STRING | NUMBER }\n"); |
| exit(-1); |
| } |
| |
| static int tap_add_ioctl(struct ifreq *ifr, uid_t uid, gid_t gid) |
| { |
| int fd; |
| int ret = -1; |
| |
| #ifdef IFF_TUN_EXCL |
| ifr->ifr_flags |= IFF_TUN_EXCL; |
| #endif |
| |
| fd = open(TUNDEV, O_RDWR); |
| if (fd < 0) { |
| perror("open"); |
| return -1; |
| } |
| if (ioctl(fd, TUNSETIFF, ifr)) { |
| perror("ioctl(TUNSETIFF)"); |
| goto out; |
| } |
| if (uid != -1 && ioctl(fd, TUNSETOWNER, uid)) { |
| perror("ioctl(TUNSETOWNER)"); |
| goto out; |
| } |
| if (gid != -1 && ioctl(fd, TUNSETGROUP, gid)) { |
| perror("ioctl(TUNSETGROUP)"); |
| goto out; |
| } |
| if (ioctl(fd, TUNSETPERSIST, 1)) { |
| perror("ioctl(TUNSETPERSIST)"); |
| goto out; |
| } |
| ret = 0; |
| out: |
| close(fd); |
| return ret; |
| } |
| |
| static int tap_del_ioctl(struct ifreq *ifr) |
| { |
| int fd = open(TUNDEV, O_RDWR); |
| int ret = -1; |
| |
| if (fd < 0) { |
| perror("open"); |
| return -1; |
| } |
| if (ioctl(fd, TUNSETIFF, ifr)) { |
| perror("ioctl(TUNSETIFF)"); |
| goto out; |
| } |
| if (ioctl(fd, TUNSETPERSIST, 0)) { |
| perror("ioctl(TUNSETPERSIST)"); |
| goto out; |
| } |
| ret = 0; |
| out: |
| close(fd); |
| return ret; |
| |
| } |
| static int parse_args(int argc, char **argv, struct ifreq *ifr, uid_t *uid, gid_t *gid) |
| { |
| int count = 0; |
| |
| memset(ifr, 0, sizeof(*ifr)); |
| |
| ifr->ifr_flags |= IFF_NO_PI; |
| |
| while (argc > 0) { |
| if (matches(*argv, "mode") == 0) { |
| NEXT_ARG(); |
| if (matches(*argv, "tun") == 0) { |
| if (ifr->ifr_flags & IFF_TAP) { |
| fprintf(stderr,"You managed to ask for more than one tunnel mode.\n"); |
| exit(-1); |
| } |
| ifr->ifr_flags |= IFF_TUN; |
| } else if (matches(*argv, "tap") == 0) { |
| if (ifr->ifr_flags & IFF_TUN) { |
| fprintf(stderr,"You managed to ask for more than one tunnel mode.\n"); |
| exit(-1); |
| } |
| ifr->ifr_flags |= IFF_TAP; |
| } else { |
| fprintf(stderr,"Unknown tunnel mode \"%s\"\n", *argv); |
| exit(-1); |
| } |
| } else if (uid && matches(*argv, "user") == 0) { |
| char *end; |
| unsigned long user; |
| |
| NEXT_ARG(); |
| if (**argv && ((user = strtol(*argv, &end, 10)), !*end)) |
| *uid = user; |
| else { |
| struct passwd *pw = getpwnam(*argv); |
| if (!pw) { |
| fprintf(stderr, "invalid user \"%s\"\n", *argv); |
| exit(-1); |
| } |
| *uid = pw->pw_uid; |
| } |
| } else if (gid && matches(*argv, "group") == 0) { |
| char *end; |
| unsigned long group; |
| |
| NEXT_ARG(); |
| |
| if (**argv && ((group = strtol(*argv, &end, 10)), !*end)) |
| *gid = group; |
| else { |
| struct group *gr = getgrnam(*argv); |
| if (!gr) { |
| fprintf(stderr, "invalid group \"%s\"\n", *argv); |
| exit(-1); |
| } |
| *gid = gr->gr_gid; |
| } |
| } else if (matches(*argv, "pi") == 0) { |
| ifr->ifr_flags &= ~IFF_NO_PI; |
| } else if (matches(*argv, "one_queue") == 0) { |
| ifr->ifr_flags |= IFF_ONE_QUEUE; |
| } else if (matches(*argv, "vnet_hdr") == 0) { |
| ifr->ifr_flags |= IFF_VNET_HDR; |
| } else if (matches(*argv, "multi_queue") == 0) { |
| ifr->ifr_flags |= IFF_MULTI_QUEUE; |
| } else if (matches(*argv, "dev") == 0) { |
| NEXT_ARG(); |
| strncpy(ifr->ifr_name, *argv, IFNAMSIZ-1); |
| } else { |
| if (matches(*argv, "name") == 0) { |
| NEXT_ARG(); |
| } else if (matches(*argv, "help") == 0) |
| usage(); |
| if (ifr->ifr_name[0]) |
| duparg2("name", *argv); |
| strncpy(ifr->ifr_name, *argv, IFNAMSIZ); |
| } |
| count++; |
| argc--; argv++; |
| } |
| |
| if (!(ifr->ifr_flags & TUN_TYPE_MASK)) { |
| fprintf(stderr, "You failed to specify a tunnel mode\n"); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| |
| static int do_add(int argc, char **argv) |
| { |
| struct ifreq ifr; |
| uid_t uid = -1; |
| gid_t gid = -1; |
| |
| if (parse_args(argc, argv, &ifr, &uid, &gid) < 0) |
| return -1; |
| |
| return tap_add_ioctl(&ifr, uid, gid); |
| } |
| |
| static int do_del(int argc, char **argv) |
| { |
| struct ifreq ifr; |
| |
| if (parse_args(argc, argv, &ifr, NULL, NULL) < 0) |
| return -1; |
| |
| return tap_del_ioctl(&ifr); |
| } |
| |
| static int read_prop(char *dev, char *prop, long *value) |
| { |
| char fname[IFNAMSIZ+25], buf[80], *endp; |
| ssize_t len; |
| int fd; |
| long result; |
| |
| sprintf(fname, "/sys/class/net/%s/%s", dev, prop); |
| fd = open(fname, O_RDONLY); |
| if (fd < 0) { |
| if (strcmp(prop, "tun_flags")) |
| fprintf(stderr, "open %s: %s\n", fname, |
| strerror(errno)); |
| return -1; |
| } |
| len = read(fd, buf, sizeof(buf)-1); |
| close(fd); |
| if (len < 0) { |
| fprintf(stderr, "read %s: %s", fname, strerror(errno)); |
| return -1; |
| } |
| |
| buf[len] = 0; |
| result = strtol(buf, &endp, 0); |
| if (*endp != '\n') { |
| fprintf(stderr, "Failed to parse %s\n", fname); |
| return -1; |
| } |
| *value = result; |
| return 0; |
| } |
| |
| static void print_flags(long flags) |
| { |
| if (flags & IFF_TUN) |
| printf(" tun"); |
| |
| if (flags & IFF_TAP) |
| printf(" tap"); |
| |
| if (!(flags & IFF_NO_PI)) |
| printf(" pi"); |
| |
| if (flags & IFF_ONE_QUEUE) |
| printf(" one_queue"); |
| |
| if (flags & IFF_VNET_HDR) |
| printf(" vnet_hdr"); |
| |
| flags &= ~(IFF_TUN|IFF_TAP|IFF_NO_PI|IFF_ONE_QUEUE|IFF_VNET_HDR); |
| if (flags) |
| printf(" UNKNOWN_FLAGS:%lx", flags); |
| } |
| |
| static int do_show(int argc, char **argv) |
| { |
| DIR *dir; |
| struct dirent *d; |
| long flags, owner = -1, group = -1; |
| |
| dir = opendir("/sys/class/net"); |
| if (!dir) { |
| perror("opendir"); |
| return -1; |
| } |
| while ((d = readdir(dir))) { |
| if (d->d_name[0] == '.' && |
| (d->d_name[1] == 0 || d->d_name[1] == '.')) |
| continue; |
| |
| if (read_prop(d->d_name, "tun_flags", &flags)) |
| continue; |
| |
| read_prop(d->d_name, "owner", &owner); |
| read_prop(d->d_name, "group", &group); |
| |
| printf("%s:", d->d_name); |
| print_flags(flags); |
| if (owner != -1) |
| printf(" user %ld", owner); |
| if (group != -1) |
| printf(" group %ld", group); |
| printf("\n"); |
| } |
| closedir(dir); |
| return 0; |
| } |
| |
| int do_iptuntap(int argc, char **argv) |
| { |
| if (argc > 0) { |
| if (matches(*argv, "add") == 0) |
| return do_add(argc-1, argv+1); |
| if (matches(*argv, "delete") == 0) |
| return do_del(argc-1, argv+1); |
| if (matches(*argv, "show") == 0 || |
| matches(*argv, "lst") == 0 || |
| matches(*argv, "list") == 0) |
| return do_show(argc-1, argv+1); |
| if (matches(*argv, "help") == 0) |
| usage(); |
| } else |
| return do_show(0, NULL); |
| |
| fprintf(stderr, "Command \"%s\" is unknown, try \"ip tuntap help\".\n", |
| *argv); |
| exit(-1); |
| } |