tools/testing/selftests/net/ipv6_flowlabel.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Test IPV6_FLOWINFO cmsg on send and recv */
   3
   4 #define _GNU_SOURCE
   5
   6 #include <arpa/inet.h>
   7 #include <asm/byteorder.h>
   8 #include <error.h>
   9 #include <errno.h>
  10 #include <fcntl.h>
  11 #include <limits.h>
  12 #include <linux/icmpv6.h>
  13 #include <linux/in6.h>
  14 #include <stdbool.h>
  15 #include <stdio.h>
  16 #include <stdint.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <sys/socket.h>
  20 #include <sys/stat.h>
  21 #include <sys/time.h>
  22 #include <sys/types.h>
  23 #include <unistd.h>
  24
  25 /* uapi/glibc weirdness may leave this undefined */
  26 #ifndef IPV6_FLOWINFO
  27 #define IPV6_FLOWINFO 11
  28 #endif
  29
  30 #ifndef IPV6_FLOWLABEL_MGR
  31 #define IPV6_FLOWLABEL_MGR 32
  32 #endif
  33 #ifndef IPV6_FLOWINFO_SEND
  34 #define IPV6_FLOWINFO_SEND 33
  35 #endif
  36
  37 #define FLOWLABEL_WILDCARD      ((uint32_t) -1)
  38
  39 static const char cfg_data[]    = "a";
  40 static uint32_t cfg_label       = 1;
  41 static bool use_ping;
  42 static bool use_flowinfo_send;
  43
  44 static struct icmp6hdr icmp6 = {
  45         .icmp6_type = ICMPV6_ECHO_REQUEST
  46 };
  47
  48 static struct sockaddr_in6 addr = {
  49         .sin6_family = AF_INET6,
  50         .sin6_addr = IN6ADDR_LOOPBACK_INIT,
  51 };
  52
  53 static void do_send(int fd, bool with_flowlabel, uint32_t flowlabel)
  54 {
  55         char control[CMSG_SPACE(sizeof(flowlabel))] = {0};
  56         struct msghdr msg = {0};
  57         struct iovec iov = {
  58                 .iov_base = (char *)cfg_data,
  59                 .iov_len = sizeof(cfg_data)
  60         };
  61         int ret;
  62
  63         if (use_ping) {
  64                 iov.iov_base = &icmp6;
  65                 iov.iov_len = sizeof(icmp6);
  66         }
  67
  68         msg.msg_iov = &iov;
  69         msg.msg_iovlen = 1;
  70
  71         if (use_flowinfo_send) {
  72                 msg.msg_name = &addr;
  73                 msg.msg_namelen = sizeof(addr);
  74         } else if (with_flowlabel) {
  75                 struct cmsghdr *cm;
  76
  77                 cm = (void *)control;
  78                 cm->cmsg_len = CMSG_LEN(sizeof(flowlabel));
  79                 cm->cmsg_level = SOL_IPV6;
  80                 cm->cmsg_type = IPV6_FLOWINFO;
  81                 *(uint32_t *)CMSG_DATA(cm) = htonl(flowlabel);
  82
  83                 msg.msg_control = control;
  84                 msg.msg_controllen = sizeof(control);
  85         }
  86
  87         ret = sendmsg(fd, &msg, 0);
  88         if (ret == -1)
  89                 error(1, errno, "send");
  90
  91         if (with_flowlabel)
  92                 fprintf(stderr, "sent with label %u\n", flowlabel);
  93         else
  94                 fprintf(stderr, "sent without label\n");
  95 }
  96
  97 static void do_recv(int fd, bool with_flowlabel, uint32_t expect)
  98 {
  99         char control[CMSG_SPACE(sizeof(expect))];
 100         char data[sizeof(cfg_data)];
 101         struct msghdr msg = {0};
 102         struct iovec iov = {0};
 103         struct cmsghdr *cm;
 104         uint32_t flowlabel;
 105         int ret;
 106
 107         iov.iov_base = data;
 108         iov.iov_len = sizeof(data);
 109
 110         msg.msg_iov = &iov;
 111         msg.msg_iovlen = 1;
 112
 113         memset(control, 0, sizeof(control));
 114         msg.msg_control = control;
 115         msg.msg_controllen = sizeof(control);
 116
 117         ret = recvmsg(fd, &msg, 0);
 118         if (ret == -1)
 119                 error(1, errno, "recv");
 120         if (use_ping)
 121                 goto parse_cmsg;
 122         if (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))
 123                 error(1, 0, "recv: truncated");
 124         if (ret != sizeof(cfg_data))
 125                 error(1, 0, "recv: length mismatch");
 126         if (memcmp(data, cfg_data, sizeof(data)))
 127                 error(1, 0, "recv: data mismatch");
 128
 129 parse_cmsg:
 130         cm = CMSG_FIRSTHDR(&msg);
 131         if (with_flowlabel) {
 132                 if (!cm)
 133                         error(1, 0, "recv: missing cmsg");
 134                 if (CMSG_NXTHDR(&msg, cm))
 135                         error(1, 0, "recv: too many cmsg");
 136                 if (cm->cmsg_level != SOL_IPV6 ||
 137                     cm->cmsg_type != IPV6_FLOWINFO)
 138                         error(1, 0, "recv: unexpected cmsg level or type");
 139
 140                 flowlabel = ntohl(*(uint32_t *)CMSG_DATA(cm));
 141                 fprintf(stderr, "recv with label %u\n", flowlabel);
 142
 143                 if (expect != FLOWLABEL_WILDCARD && expect != flowlabel) {
 144                         fprintf(stderr, "recv: incorrect flowlabel %u != %u\n",
 145                                         flowlabel, expect);
 146                         error(1, 0, "recv: flowlabel is wrong");
 147                 }
 148
 149         } else {
 150                 fprintf(stderr, "recv without label\n");
 151         }
 152 }
 153
 154 static bool get_autoflowlabel_enabled(void)
 155 {
 156         int fd, ret;
 157         char val;
 158
 159         fd = open("/proc/sys/net/ipv6/auto_flowlabels", O_RDONLY);
 160         if (fd == -1)
 161                 error(1, errno, "open sysctl");
 162
 163         ret = read(fd, &val, 1);
 164         if (ret == -1)
 165                 error(1, errno, "read sysctl");
 166         if (ret == 0)
 167                 error(1, 0, "read sysctl: 0");
 168
 169         if (close(fd))
 170                 error(1, errno, "close sysctl");
 171
 172         return val == '1';
 173 }
 174
 175 static void flowlabel_get(int fd, uint32_t label, uint8_t share, uint16_t flags)
 176 {
 177         struct in6_flowlabel_req req = {
 178                 .flr_action = IPV6_FL_A_GET,
 179                 .flr_label = htonl(label),
 180                 .flr_flags = flags,
 181                 .flr_share = share,
 182         };
 183
 184         /* do not pass IPV6_ADDR_ANY or IPV6_ADDR_MAPPED */
 185         req.flr_dst.s6_addr[0] = 0xfd;
 186         req.flr_dst.s6_addr[15] = 0x1;
 187
 188         if (setsockopt(fd, SOL_IPV6, IPV6_FLOWLABEL_MGR, &req, sizeof(req)))
 189                 error(1, errno, "setsockopt flowlabel get");
 190 }
 191
 192 static void parse_opts(int argc, char **argv)
 193 {
 194         int c;
 195
 196         while ((c = getopt(argc, argv, "l:ps")) != -1) {
 197                 switch (c) {
 198                 case 'l':
 199                         cfg_label = strtoul(optarg, NULL, 0);
 200                         break;
 201                 case 'p':
 202                         use_ping = true;
 203                         break;
 204                 case 's':
 205                         use_flowinfo_send = true;
 206                         break;
 207                 default:
 208                         error(1, 0, "%s: parse error", argv[0]);
 209                 }
 210         }
 211 }
 212
 213 int main(int argc, char **argv)
 214 {
 215         const int one = 1;
 216         int fdt, fdr;
 217         int prot = 0;
 218
 219         addr.sin6_port = htons(8000);
 220
 221         parse_opts(argc, argv);
 222
 223         if (use_ping) {
 224                 fprintf(stderr, "attempting to use ping sockets\n");
 225                 prot = IPPROTO_ICMPV6;
 226         }
 227
 228         fdt = socket(PF_INET6, SOCK_DGRAM, prot);
 229         if (fdt == -1)
 230                 error(1, errno, "socket t");
 231
 232         fdr = use_ping ? fdt : socket(PF_INET6, SOCK_DGRAM, 0);
 233         if (fdr == -1)
 234                 error(1, errno, "socket r");
 235
 236         if (connect(fdt, (void *)&addr, sizeof(addr)))
 237                 error(1, errno, "connect");
 238         if (!use_ping && bind(fdr, (void *)&addr, sizeof(addr)))
 239                 error(1, errno, "bind");
 240
 241         flowlabel_get(fdt, cfg_label, IPV6_FL_S_EXCL, IPV6_FL_F_CREATE);
 242
 243         if (setsockopt(fdr, SOL_IPV6, IPV6_FLOWINFO, &one, sizeof(one)))
 244                 error(1, errno, "setsockopt flowinfo");
 245
 246         if (get_autoflowlabel_enabled()) {
 247                 fprintf(stderr, "send no label: recv auto flowlabel\n");
 248                 do_send(fdt, false, 0);
 249                 do_recv(fdr, true, FLOWLABEL_WILDCARD);
 250         } else {
 251                 fprintf(stderr, "send no label: recv no label (auto off)\n");
 252                 do_send(fdt, false, 0);
 253                 do_recv(fdr, false, 0);
 254         }
 255
 256         if (use_flowinfo_send) {
 257                 fprintf(stderr, "using IPV6_FLOWINFO_SEND to send label\n");
 258                 addr.sin6_flowinfo = htonl(cfg_label);
 259                 if (setsockopt(fdt, SOL_IPV6, IPV6_FLOWINFO_SEND, &one,
 260                                sizeof(one)) == -1)
 261                         error(1, errno, "setsockopt flowinfo_send");
 262         }
 263
 264         fprintf(stderr, "send label\n");
 265         do_send(fdt, true, cfg_label);
 266         do_recv(fdr, true, cfg_label);
 267
 268         if (close(fdr))
 269                 error(1, errno, "close r");
 270         if (!use_ping && close(fdt))
 271                 error(1, errno, "close t");
 272
 273         return 0;
 274 }