From a0e0018c9a7ef5ce7f6d2c3ae16aecbbd16a8f67 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 4 May 2024 16:18:53 +0200 Subject: Adding upstream version 6.1.0. Signed-off-by: Daniel Baumann --- ip/iptuntap.c | 570 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 570 insertions(+) create mode 100644 ip/iptuntap.c (limited to 'ip/iptuntap.c') diff --git a/ip/iptuntap.c b/ip/iptuntap.c new file mode 100644 index 0000000..8e4e09b --- /dev/null +++ b/ip/iptuntap.c @@ -0,0 +1,570 @@ +/* + * 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 + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "rt_names.h" +#include "utils.h" +#include "ip_common.h" + +static const char drv_name[] = "tun"; + +#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" + " [ mode { tun | tap } ] [ user USER ] [ group GROUP ]\n" + " [ one_queue ] [ pi ] [ vnet_hdr ] [ multi_queue ] [ name NAME ]\n" + "\n" + "Where: USER := { STRING | NUMBER }\n" + " 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(); + if (get_ifname(ifr->ifr_name, *argv)) + invarg("\"dev\" not a valid ifname", *argv); + } else { + if (matches(*argv, "name") == 0) { + NEXT_ARG(); + } else if (matches(*argv, "help") == 0) + usage(); + if (ifr->ifr_name[0]) + duparg2("name", *argv); + if (get_ifname(ifr->ifr_name, *argv)) + invarg("\"name\" not a valid ifname", *argv); + } + 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 void print_flags(long flags) +{ + open_json_array(PRINT_JSON, "flags"); + + if (flags & IFF_TUN) + print_string(PRINT_ANY, NULL, " %s", "tun"); + + if (flags & IFF_TAP) + print_string(PRINT_ANY, NULL, " %s", "tap"); + + if (!(flags & IFF_NO_PI)) + print_string(PRINT_ANY, NULL, " %s", "pi"); + + if (flags & IFF_ONE_QUEUE) + print_string(PRINT_ANY, NULL, " %s", "one_queue"); + + if (flags & IFF_MULTI_QUEUE) + print_string(PRINT_ANY, NULL, " %s", "multi_queue"); + + if (flags & IFF_VNET_HDR) + print_string(PRINT_ANY, NULL, " %s", "vnet_hdr"); + + if (flags & IFF_PERSIST) + print_string(PRINT_ANY, NULL, " %s", "persist"); + + if (!(flags & IFF_NOFILTER)) + print_string(PRINT_ANY, NULL, " %s", "filter"); + + flags &= ~(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE | + IFF_MULTI_QUEUE | IFF_VNET_HDR | IFF_PERSIST | + IFF_NOFILTER); + if (flags) + print_0xhex(PRINT_ANY, NULL, " %#llx", flags); + + close_json_array(PRINT_JSON, NULL); +} + +static void show_processes(const char *name) +{ + glob_t globbuf = { }; + char **fd_path; + int err; + + err = glob("/proc/[0-9]*/fd/[0-9]*", GLOB_NOSORT, + NULL, &globbuf); + if (err) + return; + + open_json_array(PRINT_JSON, "processes"); + + fd_path = globbuf.gl_pathv; + while (*fd_path) { + const char *dev_net_tun = "/dev/net/tun"; + const size_t linkbuf_len = strlen(dev_net_tun) + 2; + char linkbuf[linkbuf_len], *fdinfo; + int pid, fd; + FILE *f; + + if (sscanf(*fd_path, "/proc/%d/fd/%d", &pid, &fd) != 2) + goto next; + + if (pid == getpid()) + goto next; + + err = readlink(*fd_path, linkbuf, linkbuf_len - 1); + if (err < 0) { + perror("readlink"); + goto next; + } + linkbuf[err] = '\0'; + if (strcmp(dev_net_tun, linkbuf)) + goto next; + + if (asprintf(&fdinfo, "/proc/%d/fdinfo/%d", pid, fd) < 0) + goto next; + + f = fopen(fdinfo, "r"); + free(fdinfo); + if (!f) { + perror("fopen"); + goto next; + } + + while (!feof(f)) { + char *key = NULL, *value = NULL; + + err = fscanf(f, "%m[^:]: %ms\n", &key, &value); + if (err == EOF) { + if (ferror(f)) + perror("fscanf"); + break; + } else if (err == 2 && + !strcmp("iff", key) && + !strcmp(name, value)) { + SPRINT_BUF(pname); + + if (get_task_name(pid, pname, sizeof(pname))) + print_string(PRINT_ANY, "name", + "%s", ""); + else + print_string(PRINT_ANY, "name", + "%s", pname); + + print_uint(PRINT_ANY, "pid", "(%d)", pid); + } + + free(key); + free(value); + } + if (fclose(f)) + perror("fclose"); + +next: + ++fd_path; + } + close_json_array(PRINT_JSON, NULL); + + globfree(&globbuf); +} + +static int tuntap_filter_req(struct nlmsghdr *nlh, int reqlen) +{ + struct rtattr *linkinfo; + int err; + + linkinfo = addattr_nest(nlh, reqlen, IFLA_LINKINFO); + + err = addattr_l(nlh, reqlen, IFLA_INFO_KIND, + drv_name, sizeof(drv_name) - 1); + if (err) + return err; + + addattr_nest_end(nlh, linkinfo); + + return 0; +} + +static int print_tuntap(struct nlmsghdr *n, void *arg) +{ + struct ifinfomsg *ifi = NLMSG_DATA(n); + struct rtattr *tb[IFLA_MAX+1]; + struct rtattr *linkinfo[IFLA_INFO_MAX+1]; + const char *name, *kind; + long flags, owner = -1, group = -1; + + if (n->nlmsg_type != RTM_NEWLINK && n->nlmsg_type != RTM_DELLINK) + return 0; + + if (n->nlmsg_len < NLMSG_LENGTH(sizeof(*ifi))) + return -1; + + switch (ifi->ifi_type) { + case ARPHRD_NONE: + case ARPHRD_ETHER: + break; + default: + return 0; + } + + parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), IFLA_PAYLOAD(n)); + + if (!tb[IFLA_IFNAME]) + return 0; + + if (!tb[IFLA_LINKINFO]) + return 0; + + parse_rtattr_nested(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO]); + + if (!linkinfo[IFLA_INFO_KIND]) + return 0; + + kind = rta_getattr_str(linkinfo[IFLA_INFO_KIND]); + if (strcmp(kind, drv_name)) + return 0; + + name = rta_getattr_str(tb[IFLA_IFNAME]); + + if (read_prop(name, "tun_flags", &flags)) + return 0; + if (read_prop(name, "owner", &owner)) + return 0; + if (read_prop(name, "group", &group)) + return 0; + + open_json_object(NULL); + print_color_string(PRINT_ANY, COLOR_IFNAME, + "ifname", "%s:", name); + print_flags(flags); + if (owner != -1) + print_u64(PRINT_ANY, "user", + " user %ld", owner); + if (group != -1) + print_u64(PRINT_ANY, "group", + " group %ld", group); + + if (show_details) { + print_string(PRINT_FP, NULL, + "%s\tAttached to processes:", _SL_); + show_processes(name); + } + close_json_object(); + print_string(PRINT_FP, NULL, "%s", "\n"); + + return 0; +} + +static int do_show(int argc, char **argv) +{ + if (rtnl_linkdump_req_filter_fn(&rth, AF_UNSPEC, + tuntap_filter_req) < 0) { + perror("Cannot send dump request\n"); + return -1; + } + + new_json_obj(json); + + if (rtnl_dump_filter(&rth, print_tuntap, NULL) < 0) { + fprintf(stderr, "Dump terminated\n"); + return -1; + } + + delete_json_obj(); + fflush(stdout); + + 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); +} + +static void print_owner(FILE *f, uid_t uid) +{ + struct passwd *pw = getpwuid(uid); + + if (pw) + print_string(PRINT_ANY, "user", "user %s ", pw->pw_name); + else + print_uint(PRINT_ANY, "user", "user %u ", uid); +} + +static void print_group(FILE *f, gid_t gid) +{ + struct group *group = getgrgid(gid); + + if (group) + print_string(PRINT_ANY, "group", "group %s ", group->gr_name); + else + print_uint(PRINT_ANY, "group", "group %u ", gid); +} + +static void print_mq(FILE *f, struct rtattr *tb[]) +{ + if (!tb[IFLA_TUN_MULTI_QUEUE] || + !rta_getattr_u8(tb[IFLA_TUN_MULTI_QUEUE])) { + if (is_json_context()) + print_bool(PRINT_JSON, "multi_queue", NULL, false); + return; + } + + print_bool(PRINT_ANY, "multi_queue", "multi_queue ", true); + + if (tb[IFLA_TUN_NUM_QUEUES]) { + print_uint(PRINT_ANY, "numqueues", "numqueues %u ", + rta_getattr_u32(tb[IFLA_TUN_NUM_QUEUES])); + } + + if (tb[IFLA_TUN_NUM_DISABLED_QUEUES]) { + print_uint(PRINT_ANY, "numdisabled", "numdisabled %u ", + rta_getattr_u32(tb[IFLA_TUN_NUM_DISABLED_QUEUES])); + } +} + +static void print_type(FILE *f, __u8 type) +{ + SPRINT_BUF(buf); + const char *str = buf; + + if (type == IFF_TUN) + str = "tun"; + else if (type == IFF_TAP) + str = "tap"; + else + snprintf(buf, sizeof(buf), "UNKNOWN:%hhu", type); + + print_string(PRINT_ANY, "type", "type %s ", str); +} + +static void tun_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[]) +{ + if (!tb) + return; + + if (tb[IFLA_TUN_TYPE]) + print_type(f, rta_getattr_u8(tb[IFLA_TUN_TYPE])); + + if (tb[IFLA_TUN_PI]) + print_on_off(PRINT_ANY, "pi", "pi %s ", + rta_getattr_u8(tb[IFLA_TUN_PI])); + + if (tb[IFLA_TUN_VNET_HDR]) { + print_on_off(PRINT_ANY, "vnet_hdr", "vnet_hdr %s ", + rta_getattr_u8(tb[IFLA_TUN_VNET_HDR])); + } + + print_mq(f, tb); + + if (tb[IFLA_TUN_PERSIST]) + print_on_off(PRINT_ANY, "persist", "persist %s ", + rta_getattr_u8(tb[IFLA_TUN_PERSIST])); + + if (tb[IFLA_TUN_OWNER]) + print_owner(f, rta_getattr_u32(tb[IFLA_TUN_OWNER])); + + if (tb[IFLA_TUN_GROUP]) + print_group(f, rta_getattr_u32(tb[IFLA_TUN_GROUP])); +} + +struct link_util tun_link_util = { + .id = "tun", + .maxattr = IFLA_TUN_MAX, + .print_opt = tun_print_opt, +}; -- cgit v1.2.3