Quelle  ipv6_flowlabel_mgr.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/* Test IPV6_FLOWINFO_MGR */

#define _GNU_SOURCE

#include <arpa/inet.h>
#include <error.h>
#include <errno.h>
#include <limits.h>
#include <linux/in6.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

/* uapi/glibc weirdness may leave this undefined */
#ifndef IPV6_FLOWLABEL_MGR
#define IPV6_FLOWLABEL_MGR 32
#endif

/* from net/ipv6/ip6_flowlabel.c */
#define FL_MIN_LINGER  6

#define explain(x)       \
 do { if (cfg_verbose) fprintf(stderr, " " x "\n"); } while (0)

#define __expect(x)       \
 do {        \
  if (!(x))      \
   fprintf(stderr, "[OK] " #x "\n");  \
  else       \
   error(1, 0, "[ERR] " #x " (line %d)", __LINE__); \
 } while (0)

#define expect_pass(x) __expect(x)
#define expect_fail(x) __expect(!(x))

static bool cfg_long_running;
static bool cfg_verbose;

static int flowlabel_get(int fd, uint32_t label, uint8_t share, uint16_t flags)
{
 struct in6_flowlabel_req req = {
  .flr_action = IPV6_FL_A_GET,
  .flr_label = htonl(label),
  .flr_flags = flags,
  .flr_share = share,
 };

 /* do not pass IPV6_ADDR_ANY or IPV6_ADDR_MAPPED */
 req.flr_dst.s6_addr[0] = 0xfd;
 req.flr_dst.s6_addr[15] = 0x1;

 return setsockopt(fd, SOL_IPV6, IPV6_FLOWLABEL_MGR, &req, sizeof(req));
}

static int flowlabel_put(int fd, uint32_t label)
{
 struct in6_flowlabel_req req = {
  .flr_action = IPV6_FL_A_PUT,
  .flr_label = htonl(label),
 };

 return setsockopt(fd, SOL_IPV6, IPV6_FLOWLABEL_MGR, &req, sizeof(req));
}

static void run_tests(int fd)
{
 int wstatus;
 pid_t pid;

 explain("cannot get non-existent label");
 expect_fail(flowlabel_get(fd, 1, IPV6_FL_S_ANY, 0));

 explain("cannot put non-existent label");
 expect_fail(flowlabel_put(fd, 1));

 explain("cannot create label greater than 20 bits");
 expect_fail(flowlabel_get(fd, 0x1FFFFF, IPV6_FL_S_ANY,
      IPV6_FL_F_CREATE));

 explain("create a new label (FL_F_CREATE)");
 expect_pass(flowlabel_get(fd, 1, IPV6_FL_S_ANY, IPV6_FL_F_CREATE));
 explain("can get the label (without FL_F_CREATE)");
 expect_pass(flowlabel_get(fd, 1, IPV6_FL_S_ANY, 0));
 explain("can get it again with create flag set, too");
 expect_pass(flowlabel_get(fd, 1, IPV6_FL_S_ANY, IPV6_FL_F_CREATE));
 explain("cannot get it again with the exclusive (FL_FL_EXCL) flag");
 expect_fail(flowlabel_get(fd, 1, IPV6_FL_S_ANY,
      IPV6_FL_F_CREATE | IPV6_FL_F_EXCL));
 explain("can now put exactly three references");
 expect_pass(flowlabel_put(fd, 1));
 expect_pass(flowlabel_put(fd, 1));
 expect_pass(flowlabel_put(fd, 1));
 expect_fail(flowlabel_put(fd, 1));

 explain("create a new exclusive label (FL_S_EXCL)");
 expect_pass(flowlabel_get(fd, 2, IPV6_FL_S_EXCL, IPV6_FL_F_CREATE));
 explain("cannot get it again in non-exclusive mode");
 expect_fail(flowlabel_get(fd, 2, IPV6_FL_S_ANY,  IPV6_FL_F_CREATE));
 explain("cannot get it again in exclusive mode either");
 expect_fail(flowlabel_get(fd, 2, IPV6_FL_S_EXCL, IPV6_FL_F_CREATE));
 expect_pass(flowlabel_put(fd, 2));

 if (cfg_long_running) {
  explain("cannot reuse the label, due to linger");
  expect_fail(flowlabel_get(fd, 2, IPV6_FL_S_ANY,
       IPV6_FL_F_CREATE));
  explain("after sleep, can reuse");
  sleep(FL_MIN_LINGER * 2 + 1);
  expect_pass(flowlabel_get(fd, 2, IPV6_FL_S_ANY,
       IPV6_FL_F_CREATE));
 }

 explain("create a new user-private label (FL_S_USER)");
 expect_pass(flowlabel_get(fd, 3, IPV6_FL_S_USER, IPV6_FL_F_CREATE));
 explain("cannot get it again in non-exclusive mode");
 expect_fail(flowlabel_get(fd, 3, IPV6_FL_S_ANY, 0));
 explain("cannot get it again in exclusive mode");
 expect_fail(flowlabel_get(fd, 3, IPV6_FL_S_EXCL, 0));
 explain("can get it again in user mode");
 expect_pass(flowlabel_get(fd, 3, IPV6_FL_S_USER, 0));
 explain("child process can get it too, but not after setuid(nobody)");
 pid = fork();
 if (pid == -1)
  error(1, errno, "fork");
 if (!pid) {
  expect_pass(flowlabel_get(fd, 3, IPV6_FL_S_USER, 0));
  if (setuid(USHRT_MAX))
   fprintf(stderr, "[INFO] skip setuid child test\n");
  else
   expect_fail(flowlabel_get(fd, 3, IPV6_FL_S_USER, 0));
  exit(0);
 }
 if (wait(&wstatus) == -1)
  error(1, errno, "wait");
 if (!WIFEXITED(wstatus) || WEXITSTATUS(wstatus) != 0)
  error(1, errno, "wait: unexpected child result");

 explain("create a new process-private label (FL_S_PROCESS)");
 expect_pass(flowlabel_get(fd, 4, IPV6_FL_S_PROCESS, IPV6_FL_F_CREATE));
 explain("can get it again");
 expect_pass(flowlabel_get(fd, 4, IPV6_FL_S_PROCESS, 0));
 explain("child process cannot can get it");
 pid = fork();
 if (pid == -1)
  error(1, errno, "fork");
 if (!pid) {
  expect_fail(flowlabel_get(fd, 4, IPV6_FL_S_PROCESS, 0));
  exit(0);
 }
 if (wait(&wstatus) == -1)
  error(1, errno, "wait");
 if (!WIFEXITED(wstatus) || WEXITSTATUS(wstatus) != 0)
  error(1, errno, "wait: unexpected child result");
}

static void parse_opts(int argc, char **argv)
{
 int c;

 while ((c = getopt(argc, argv, "lv")) != -1) {
  switch (c) {
  case 'l':
   cfg_long_running = true;
   break;
  case 'v':
   cfg_verbose = true;
   break;
  default:
   error(1, 0, "%s: parse error", argv[0]);
  }
 }
}

int main(int argc, char **argv)
{
 int fd;

 parse_opts(argc, argv);

 fd = socket(PF_INET6, SOCK_DGRAM, 0);
 if (fd == -1)
  error(1, errno, "socket");

 run_tests(fd);

 if (close(fd))
  error(1, errno, "close");

 return 0;
}