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-rw-r--r--ip/iptuntap.c562
1 files changed, 562 insertions, 0 deletions
diff --git a/ip/iptuntap.c b/ip/iptuntap.c
new file mode 100644
index 0000000..b7018a6
--- /dev/null
+++ b/ip/iptuntap.c
@@ -0,0 +1,562 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * iptunnel.c "ip tuntap"
+ *
+ * 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 <linux/if_arp.h>
+#include <pwd.h>
+#include <grp.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <errno.h>
+#include <glob.h>
+
+#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)
+{
+ 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);
+ }
+ 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 size_t linkbuf_len = strlen(TUNDEV) + 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(TUNDEV, 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", "<NULL>");
+ 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");
+ delete_json_obj();
+ 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,
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-08 19:15:38 +0000