granicus.if.org Git - strace/blob - socketutils.c

   1 /*
   2  * Copyright (c) 2014 Zubin Mithra <zubin.mithra@gmail.com>
   3  * Copyright (c) 2014-2016 Dmitry V. Levin <ldv@altlinux.org>
   4  * Copyright (c) 2014-2018 The strace developers.
   5  * All rights reserved.
   6  *
   7  * SPDX-License-Identifier: LGPL-2.1-or-later
   8  */
   9
  10 #include "defs.h"
  11 #include <netinet/in.h>
  12 #include <sys/socket.h>
  13 #include <arpa/inet.h>
  14 #include "netlink.h"
  15 #include <linux/sock_diag.h>
  16 #include <linux/inet_diag.h>
  17 #include <linux/unix_diag.h>
  18 #include <linux/netlink_diag.h>
  19 #include <linux/rtnetlink.h>
  20 #include <linux/genetlink.h>
  21
  22 #include <sys/un.h>
  23 #ifndef UNIX_PATH_MAX
  24 # define UNIX_PATH_MAX sizeof(((struct sockaddr_un *) 0)->sun_path)
  25 #endif
  26
  27 #include "xstring.h"
  28
  29 #define XLAT_MACROS_ONLY
  30 #include "xlat/inet_protocols.h"
  31 #undef XLAT_MACROS_ONLY
  32
  33 typedef struct {
  34         unsigned long inode;
  35         char *details;
  36 } cache_entry;
  37
  38 #define CACHE_SIZE 1024U
  39 static cache_entry cache[CACHE_SIZE];
  40 #define CACHE_MASK (CACHE_SIZE - 1)
  41
  42 static int
  43 cache_inode_details(const unsigned long inode, char *const details)
  44 {
  45         cache_entry *e = &cache[inode & CACHE_MASK];
  46         free(e->details);
  47         e->inode = inode;
  48         e->details = details;
  49
  50         return 1;
  51 }
  52
  53 static const char *
  54 get_sockaddr_by_inode_cached(const unsigned long inode)
  55 {
  56         const cache_entry *const e = &cache[inode & CACHE_MASK];
  57         return (e && inode == e->inode) ? e->details : NULL;
  58 }
  59
  60 static bool
  61 print_sockaddr_by_inode_cached(const unsigned long inode)
  62 {
  63         const char *const details = get_sockaddr_by_inode_cached(inode);
  64         if (details) {
  65                 tprints(details);
  66                 return true;
  67         }
  68         return false;
  69 }
  70
  71 static bool
  72 send_query(struct tcb *tcp, const int fd, void *req, size_t req_size)
  73 {
  74         struct sockaddr_nl nladdr = {
  75                 .nl_family = AF_NETLINK
  76         };
  77         struct iovec iov = {
  78                 .iov_base = req,
  79                 .iov_len = req_size
  80         };
  81         const struct msghdr msg = {
  82                 .msg_name = &nladdr,
  83                 .msg_namelen = sizeof(nladdr),
  84                 .msg_iov = &iov,
  85                 .msg_iovlen = 1
  86         };
  87
  88         for (;;) {
  89                 if (sendmsg(fd, &msg, 0) < 0) {
  90                         if (errno == EINTR)
  91                                 continue;
  92                         return false;
  93                 }
  94                 return true;
  95         }
  96 }
  97
  98 static bool
  99 inet_send_query(struct tcb *tcp, const int fd, const int family,
 100                 const int proto)
 101 {
 102         struct {
 103                 const struct nlmsghdr nlh;
 104                 const struct inet_diag_req_v2 idr;
 105         } req = {
 106                 .nlh = {
 107                         .nlmsg_len = sizeof(req),
 108                         .nlmsg_type = SOCK_DIAG_BY_FAMILY,
 109                         .nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST
 110                 },
 111                 .idr = {
 112                         .sdiag_family = family,
 113                         .sdiag_protocol = proto,
 114                         .idiag_states = -1
 115                 }
 116         };
 117         return send_query(tcp, fd, &req, sizeof(req));
 118 }
 119
 120 static int
 121 inet_parse_response(const void *const data, const int data_len,
 122                     const unsigned long inode, void *opaque_data)
 123 {
 124         const char *const proto_name = opaque_data;
 125         const struct inet_diag_msg *const diag_msg = data;
 126         static const char zero_addr[sizeof(struct in6_addr)];
 127         socklen_t addr_size, text_size;
 128
 129         if (data_len < (int) NLMSG_LENGTH(sizeof(*diag_msg)))
 130                 return -1;
 131         if (diag_msg->idiag_inode != inode)
 132                 return 0;
 133
 134         switch (diag_msg->idiag_family) {
 135                 case AF_INET:
 136                         addr_size = sizeof(struct in_addr);
 137                         text_size = INET_ADDRSTRLEN;
 138                         break;
 139                 case AF_INET6:
 140                         addr_size = sizeof(struct in6_addr);
 141                         text_size = INET6_ADDRSTRLEN;
 142                         break;
 143                 default:
 144                         return -1;
 145         }
 146
 147         char src_buf[text_size];
 148         char *details;
 149
 150         /* open/closing brackets for IPv6 addresses */
 151         const char *ob = diag_msg->idiag_family == AF_INET6 ? "[" : "";
 152         const char *cb = diag_msg->idiag_family == AF_INET6 ? "]" : "";
 153
 154         if (!inet_ntop(diag_msg->idiag_family, diag_msg->id.idiag_src,
 155                        src_buf, text_size))
 156                 return -1;
 157
 158         if (diag_msg->id.idiag_dport ||
 159             memcmp(zero_addr, diag_msg->id.idiag_dst, addr_size)) {
 160                 char dst_buf[text_size];
 161
 162                 if (!inet_ntop(diag_msg->idiag_family, diag_msg->id.idiag_dst,
 163                                dst_buf, text_size))
 164                         return -1;
 165
 166                 if (asprintf(&details, "%s:[%s%s%s:%u->%s%s%s:%u]", proto_name,
 167                              ob, src_buf, cb, ntohs(diag_msg->id.idiag_sport),
 168                              ob, dst_buf, cb, ntohs(diag_msg->id.idiag_dport))
 169                     < 0)
 170                         return false;
 171         } else {
 172                 if (asprintf(&details, "%s:[%s%s%s:%u]",
 173                              proto_name, ob, src_buf, cb,
 174                              ntohs(diag_msg->id.idiag_sport)) < 0)
 175                         return false;
 176         }
 177
 178         return cache_inode_details(inode, details);
 179 }
 180
 181 static bool
 182 receive_responses(struct tcb *tcp, const int fd, const unsigned long inode,
 183                   const unsigned long expected_msg_type,
 184                   int (*parser)(const void *, int,
 185                                 unsigned long, void *),
 186                   void *opaque_data)
 187 {
 188         static union {
 189                 struct nlmsghdr hdr;
 190                 long buf[8192 / sizeof(long)];
 191         } hdr_buf;
 192
 193         struct sockaddr_nl nladdr = {
 194                 .nl_family = AF_NETLINK
 195         };
 196         struct iovec iov = {
 197                 .iov_base = hdr_buf.buf,
 198                 .iov_len = sizeof(hdr_buf.buf)
 199         };
 200         int flags = 0;
 201
 202         for (;;) {
 203                 struct msghdr msg = {
 204                         .msg_name = &nladdr,
 205                         .msg_namelen = sizeof(nladdr),
 206                         .msg_iov = &iov,
 207                         .msg_iovlen = 1
 208                 };
 209
 210                 ssize_t ret = recvmsg(fd, &msg, flags);
 211                 if (ret < 0) {
 212                         if (errno == EINTR)
 213                                 continue;
 214                         return false;
 215                 }
 216
 217                 const struct nlmsghdr *h = &hdr_buf.hdr;
 218                 if (!is_nlmsg_ok(h, ret))
 219                         return false;
 220                 for (; is_nlmsg_ok(h, ret); h = NLMSG_NEXT(h, ret)) {
 221                         if (h->nlmsg_type != expected_msg_type)
 222                                 return false;
 223                         const int rc = parser(NLMSG_DATA(h),
 224                                               h->nlmsg_len, inode, opaque_data);
 225                         if (rc > 0)
 226                                 return true;
 227                         if (rc < 0)
 228                                 return false;
 229                 }
 230                 flags = MSG_DONTWAIT;
 231         }
 232 }
 233
 234 static bool
 235 unix_send_query(struct tcb *tcp, const int fd, const unsigned long inode)
 236 {
 237         /*
 238          * The kernel bug was fixed in mainline by commit v4.5-rc6~35^2~11
 239          * and backported to stable/linux-4.4.y by commit v4.4.4~297.
 240          */
 241         const uint16_t dump_flag =
 242                 os_release < KERNEL_VERSION(4, 4, 4) ? NLM_F_DUMP : 0;
 243
 244         struct {
 245                 const struct nlmsghdr nlh;
 246                 const struct unix_diag_req udr;
 247         } req = {
 248                 .nlh = {
 249                         .nlmsg_len = sizeof(req),
 250                         .nlmsg_type = SOCK_DIAG_BY_FAMILY,
 251                         .nlmsg_flags = NLM_F_REQUEST | dump_flag
 252                 },
 253                 .udr = {
 254                         .sdiag_family = AF_UNIX,
 255                         .udiag_ino = inode,
 256                         .udiag_states = -1,
 257                         .udiag_show = UDIAG_SHOW_NAME | UDIAG_SHOW_PEER,
 258                         .udiag_cookie = { ~0U, ~0U }
 259                 }
 260         };
 261         return send_query(tcp, fd, &req, sizeof(req));
 262 }
 263
 264 static int
 265 unix_parse_response(const void *data, const int data_len,
 266                     const unsigned long inode, void *opaque_data)
 267 {
 268         const char *proto_name = opaque_data;
 269         const struct unix_diag_msg *diag_msg = data;
 270         struct rtattr *attr;
 271         int rta_len = data_len - NLMSG_LENGTH(sizeof(*diag_msg));
 272         uint32_t peer = 0;
 273         size_t path_len = 0;
 274         char path[UNIX_PATH_MAX + 1];
 275
 276         if (rta_len < 0)
 277                 return -1;
 278         if (diag_msg->udiag_ino != inode)
 279                 return 0;
 280         if (diag_msg->udiag_family != AF_UNIX)
 281                 return -1;
 282
 283         for (attr = (struct rtattr *) (diag_msg + 1);
 284              RTA_OK(attr, rta_len);
 285              attr = RTA_NEXT(attr, rta_len)) {
 286                 switch (attr->rta_type) {
 287                 case UNIX_DIAG_NAME:
 288                         if (!path_len) {
 289                                 path_len = RTA_PAYLOAD(attr);
 290                                 if (path_len > UNIX_PATH_MAX)
 291                                         path_len = UNIX_PATH_MAX;
 292                                 memcpy(path, RTA_DATA(attr), path_len);
 293                                 path[path_len] = '\0';
 294                         }
 295                         break;
 296                 case UNIX_DIAG_PEER:
 297                         if (RTA_PAYLOAD(attr) >= 4)
 298                                 peer = *(uint32_t *) RTA_DATA(attr);
 299                         break;
 300                 }
 301         }
 302
 303         /*
 304          * print obtained information in the following format:
 305          * "UNIX:[" SELF_INODE [ "->" PEER_INODE ][ "," SOCKET_FILE ] "]"
 306          */
 307         if (!peer && !path_len)
 308                 return -1;
 309
 310         char peer_str[3 + sizeof(peer) * 3];
 311         if (peer)
 312                 xsprintf(peer_str, "->%u", peer);
 313         else
 314                 peer_str[0] = '\0';
 315
 316         const char *path_str;
 317         if (path_len) {
 318                 char *outstr = alloca(4 * path_len + 4);
 319
 320                 outstr[0] = ',';
 321                 if (path[0] == '\0') {
 322                         outstr[1] = '@';
 323                         string_quote(path + 1, outstr + 2,
 324                                      path_len - 1, QUOTE_0_TERMINATED, NULL);
 325                 } else {
 326                         string_quote(path, outstr + 1,
 327                                      path_len, QUOTE_0_TERMINATED, NULL);
 328                 }
 329                 path_str = outstr;
 330         } else {
 331                 path_str = "";
 332         }
 333
 334         char *details;
 335         if (asprintf(&details, "%s:[%lu%s%s]", proto_name, inode,
 336                      peer_str, path_str) < 0)
 337                 return -1;
 338
 339         return cache_inode_details(inode, details);
 340 }
 341
 342 static bool
 343 netlink_send_query(struct tcb *tcp, const int fd, const unsigned long inode)
 344 {
 345         struct {
 346                 const struct nlmsghdr nlh;
 347                 const struct netlink_diag_req ndr;
 348         } req = {
 349                 .nlh = {
 350                         .nlmsg_len = sizeof(req),
 351                         .nlmsg_type = SOCK_DIAG_BY_FAMILY,
 352                         .nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST
 353                 },
 354                 .ndr = {
 355                         .sdiag_family = AF_NETLINK,
 356                         .sdiag_protocol = NDIAG_PROTO_ALL
 357                 }
 358         };
 359         return send_query(tcp, fd, &req, sizeof(req));
 360 }
 361
 362 static int
 363 netlink_parse_response(const void *data, const int data_len,
 364                        const unsigned long inode, void *opaque_data)
 365 {
 366         const char *proto_name = opaque_data;
 367         const struct netlink_diag_msg *const diag_msg = data;
 368         const char *netlink_proto;
 369         char *details;
 370
 371         if (data_len < (int) NLMSG_LENGTH(sizeof(*diag_msg)))
 372                 return -1;
 373         if (diag_msg->ndiag_ino != inode)
 374                 return 0;
 375
 376         if (diag_msg->ndiag_family != AF_NETLINK)
 377                 return -1;
 378
 379         netlink_proto = xlookup(netlink_protocols,
 380                                 diag_msg->ndiag_protocol);
 381
 382         if (netlink_proto) {
 383                 netlink_proto = STR_STRIP_PREFIX(netlink_proto, "NETLINK_");
 384                 if (asprintf(&details, "%s:[%s:%u]", proto_name,
 385                              netlink_proto, diag_msg->ndiag_portid) < 0)
 386                         return -1;
 387         } else {
 388                 if (asprintf(&details, "%s:[%u]", proto_name,
 389                              (unsigned) diag_msg->ndiag_protocol) < 0)
 390                         return -1;
 391         }
 392
 393         return cache_inode_details(inode, details);
 394 }
 395
 396 static const char *
 397 unix_get(struct tcb *tcp, const int fd, const int family, const int proto,
 398          const unsigned long inode, const char *name)
 399 {
 400         return unix_send_query(tcp, fd, inode)
 401                 && receive_responses(tcp, fd, inode, SOCK_DIAG_BY_FAMILY,
 402                                      unix_parse_response, (void *) name)
 403                 ? get_sockaddr_by_inode_cached(inode) : NULL;
 404 }
 405
 406 static const char *
 407 inet_get(struct tcb *tcp, const int fd, const int family, const int protocol,
 408          const unsigned long inode, const char *proto_name)
 409 {
 410         return inet_send_query(tcp, fd, family, protocol)
 411                 && receive_responses(tcp, fd, inode, SOCK_DIAG_BY_FAMILY,
 412                                      inet_parse_response, (void *) proto_name)
 413                 ? get_sockaddr_by_inode_cached(inode) : NULL;
 414 }
 415
 416 static const char *
 417 netlink_get(struct tcb *tcp, const int fd, const int family, const int protocol,
 418             const unsigned long inode, const char *proto_name)
 419 {
 420         return netlink_send_query(tcp, fd, inode)
 421                 && receive_responses(tcp, fd, inode, SOCK_DIAG_BY_FAMILY,
 422                                      netlink_parse_response,
 423                                      (void *) proto_name)
 424                 ? get_sockaddr_by_inode_cached(inode) : NULL;
 425 }
 426
 427 static const struct {
 428         const char *const name;
 429         const char * (*const get)(struct tcb *, int fd, int family,
 430                                   int protocol, unsigned long inode,
 431                                   const char *proto_name);
 432         int family;
 433         int proto;
 434 } protocols[] = {
 435         [SOCK_PROTO_UNIX]       = { "UNIX",     unix_get,       AF_UNIX},
 436         /*
 437          * inet_diag handlers are currently implemented only for TCP,
 438          * UDP(lite), SCTP, RAW, and DCCP, but we try to resolve it for all
 439          * protocols anyway, just in case.
 440          */
 441         [SOCK_PROTO_TCP]        =
 442                 { "TCP",        inet_get, AF_INET,  IPPROTO_TCP },
 443         [SOCK_PROTO_UDP]        =
 444                 { "UDP",        inet_get, AF_INET,  IPPROTO_UDP },
 445         [SOCK_PROTO_UDPLITE]    =
 446                 { "UDPLITE",    inet_get, AF_INET,  IPPROTO_UDPLITE },
 447         [SOCK_PROTO_DCCP]       =
 448                 { "DCCP",       inet_get, AF_INET,  IPPROTO_DCCP },
 449         [SOCK_PROTO_SCTP]       =
 450                 { "SCTP",       inet_get, AF_INET,  IPPROTO_SCTP },
 451         [SOCK_PROTO_L2TP_IP]    =
 452                 { "L2TP/IP",    inet_get, AF_INET,  IPPROTO_L2TP },
 453         [SOCK_PROTO_PING]       =
 454                 { "PING",       inet_get, AF_INET,  IPPROTO_ICMP },
 455         [SOCK_PROTO_RAW]        =
 456                 { "RAW",        inet_get, AF_INET,  IPPROTO_RAW },
 457         [SOCK_PROTO_TCPv6]      =
 458                 { "TCPv6",      inet_get, AF_INET6, IPPROTO_TCP },
 459         [SOCK_PROTO_UDPv6]      =
 460                 { "UDPv6",      inet_get, AF_INET6, IPPROTO_UDP },
 461         [SOCK_PROTO_UDPLITEv6]  =
 462                 { "UDPLITEv6",  inet_get, AF_INET6, IPPROTO_UDPLITE },
 463         [SOCK_PROTO_DCCPv6]     =
 464                 { "DCCPv6",     inet_get, AF_INET6, IPPROTO_DCCP },
 465         [SOCK_PROTO_SCTPv6]     =
 466                 { "SCTPv6",     inet_get, AF_INET6, IPPROTO_SCTP },
 467         [SOCK_PROTO_L2TP_IPv6]  =
 468                 { "L2TP/IPv6",  inet_get, AF_INET6, IPPROTO_L2TP },
 469         [SOCK_PROTO_PINGv6]     =
 470                 { "PINGv6",     inet_get, AF_INET6, IPPROTO_ICMP },
 471         [SOCK_PROTO_RAWv6]      =
 472                 { "RAWv6",      inet_get, AF_INET6, IPPROTO_RAW },
 473         [SOCK_PROTO_NETLINK]    = { "NETLINK",  netlink_get,    AF_NETLINK },
 474 };
 475
 476 enum sock_proto
 477 get_proto_by_name(const char *const name)
 478 {
 479         unsigned int i;
 480         for (i = (unsigned int) SOCK_PROTO_UNKNOWN + 1;
 481              i < ARRAY_SIZE(protocols); ++i) {
 482                 if (protocols[i].name && !strcmp(name, protocols[i].name))
 483                         return (enum sock_proto) i;
 484         }
 485         return SOCK_PROTO_UNKNOWN;
 486 }
 487
 488 int
 489 get_family_by_proto(enum sock_proto proto)
 490 {
 491         if ((size_t) proto < ARRAY_SIZE(protocols))
 492                 return protocols[proto].family;
 493
 494         return AF_UNSPEC;
 495 }
 496
 497 static const char *
 498 get_sockaddr_by_inode_uncached(struct tcb *tcp, const unsigned long inode,
 499                                const enum sock_proto proto)
 500 {
 501         if ((unsigned int) proto >= ARRAY_SIZE(protocols) ||
 502             (proto != SOCK_PROTO_UNKNOWN && !protocols[proto].get))
 503                 return NULL;
 504
 505         const int fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_SOCK_DIAG);
 506         if (fd < 0)
 507                 return NULL;
 508         const char *details = NULL;
 509
 510         if (proto != SOCK_PROTO_UNKNOWN) {
 511                 details = protocols[proto].get(tcp, fd, protocols[proto].family,
 512                                                protocols[proto].proto, inode,
 513                                                protocols[proto].name);
 514         } else {
 515                 unsigned int i;
 516                 for (i = (unsigned int) SOCK_PROTO_UNKNOWN + 1;
 517                      i < ARRAY_SIZE(protocols); ++i) {
 518                         if (!protocols[i].get)
 519                                 continue;
 520                         details = protocols[i].get(tcp, fd,
 521                                                    protocols[proto].family,
 522                                                    protocols[proto].proto,
 523                                                    inode,
 524                                                    protocols[proto].name);
 525                         if (details)
 526                                 break;
 527                 }
 528         }
 529
 530         close(fd);
 531         return details;
 532 }
 533
 534 static bool
 535 print_sockaddr_by_inode_uncached(struct tcb *tcp, const unsigned long inode,
 536                                  const enum sock_proto proto)
 537 {
 538         const char *details = get_sockaddr_by_inode_uncached(tcp, inode, proto);
 539
 540         if (details) {
 541                 tprints(details);
 542                 return true;
 543         }
 544
 545         if ((unsigned int) proto < ARRAY_SIZE(protocols) &&
 546             protocols[proto].name) {
 547                 tprintf("%s:[%lu]", protocols[proto].name, inode);
 548                 return true;
 549         }
 550
 551         return false;
 552 }
 553
 554 /* Given an inode number of a socket, return its protocol details.  */
 555 const char *
 556 get_sockaddr_by_inode(struct tcb *const tcp, const int fd,
 557                       const unsigned long inode)
 558 {
 559         const char *details = get_sockaddr_by_inode_cached(inode);
 560         return details ? details :
 561                 get_sockaddr_by_inode_uncached(tcp, inode, getfdproto(tcp, fd));
 562 }
 563
 564 /* Given an inode number of a socket, print out its protocol details.  */
 565 bool
 566 print_sockaddr_by_inode(struct tcb *const tcp, const int fd,
 567                         const unsigned long inode)
 568 {
 569         return print_sockaddr_by_inode_cached(inode) ? true :
 570                 print_sockaddr_by_inode_uncached(tcp, inode,
 571                                                  getfdproto(tcp, fd));
 572 }
 573
 574 /*
 575  * Managing the cache for decoding communications of Netlink GENERIC protocol
 576  *
 577  * As name shown Netlink GENERIC protocol is generic protocol. The
 578  * numbers of msg types used in the protocol are not defined
 579  * statically. Kernel defines them on demand.  So the xlat converted
 580  * from header files doesn't help for decoding the protocol. Following
 581  * codes are building xlat(dyxlat) at runtime.
 582  */
 583 static bool
 584 genl_send_dump_families(struct tcb *tcp, const int fd)
 585 {
 586         struct {
 587                 const struct nlmsghdr nlh;
 588                 struct genlmsghdr gnlh;
 589         } req = {
 590                 .nlh = {
 591                         .nlmsg_len = sizeof(req),
 592                         .nlmsg_type = GENL_ID_CTRL,
 593                         .nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 594                 },
 595                 .gnlh = {
 596                         .cmd = CTRL_CMD_GETFAMILY,
 597                 }
 598         };
 599         return send_query(tcp, fd, &req, sizeof(req));
 600 }
 601
 602 static int
 603 genl_parse_families_response(const void *const data,
 604                              const int data_len, const unsigned long inode,
 605                              void *opaque_data)
 606 {
 607         struct dyxlat *const dyxlat = opaque_data;
 608         const struct genlmsghdr *const gnlh = data;
 609         struct rtattr *attr;
 610         int rta_len = data_len - NLMSG_LENGTH(sizeof(*gnlh));
 611
 612         char *name = NULL;
 613         unsigned int name_len = 0;
 614         uint16_t *id = NULL;
 615
 616         if (rta_len < 0)
 617                 return -1;
 618         if (gnlh->cmd != CTRL_CMD_NEWFAMILY)
 619                 return -1;
 620         if (gnlh->version != 2)
 621                 return -1;
 622
 623         for (attr = (struct rtattr *) (gnlh + 1);
 624              RTA_OK(attr, rta_len);
 625              attr = RTA_NEXT(attr, rta_len)) {
 626                 switch (attr->rta_type) {
 627                 case CTRL_ATTR_FAMILY_NAME:
 628                         if (!name) {
 629                                 name = RTA_DATA(attr);
 630                                 name_len = RTA_PAYLOAD(attr);
 631                         }
 632                         break;
 633                 case CTRL_ATTR_FAMILY_ID:
 634                         if (!id && RTA_PAYLOAD(attr) == sizeof(*id))
 635                                 id = RTA_DATA(attr);
 636                         break;
 637                 }
 638
 639                 if (name && id) {
 640                         dyxlat_add_pair(dyxlat, *id, name, name_len);
 641                         name = NULL;
 642                         id = NULL;
 643                 }
 644         }
 645
 646         return 0;
 647 }
 648
 649 const struct xlat *
 650 genl_families_xlat(struct tcb *tcp)
 651 {
 652         static struct dyxlat *dyxlat;
 653
 654         if (!dyxlat) {
 655                 dyxlat = dyxlat_alloc(32);
 656
 657                 int fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC);
 658                 if (fd < 0)
 659                         goto out;
 660
 661                 if (genl_send_dump_families(tcp, fd))
 662                         receive_responses(tcp, fd, 0, GENL_ID_CTRL,
 663                                           genl_parse_families_response, dyxlat);
 664                 close(fd);
 665         }
 666
 667 out:
 668         return dyxlat_get(dyxlat);
 669 }