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    Contents of /trunk/mkinitrd-magellan/busybox/networking/libiproute/libnetlink.c

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    Revision 532 - (show annotations) (download)
    Sat Sep 1 22:45:15 2007 UTC (16 years, 8 months ago) by niro
    File MIME type: text/plain
    File size: 9112 byte(s) 
    -import if magellan mkinitrd; it is a fork of redhats mkinitrd-5.0.8 with all magellan patches and features; deprecates magellan-src/mkinitrd
    1 /* vi: set sw=4 ts=4: */
    2 /*
    3 * libnetlink.c RTnetlink service routines.
    4 *
    5 * This program is free software; you can redistribute it and/or
    6 * modify it under the terms of the GNU General Public License
    7 * as published by the Free Software Foundation; either version
    8 * 2 of the License, or (at your option) any later version.
    9 *
    10 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
    11 *
    12 */
    13
    14 #include "libbb.h"
    15 #include <sys/socket.h>
    16
    17 #include <errno.h>
    18 #include <string.h>
    19 #include <time.h>
    20 #include <unistd.h>
    21
    22 #include <sys/uio.h>
    23
    24 #include "libnetlink.h"
    25
    26 void rtnl_close(struct rtnl_handle *rth)
    27 {
    28 close(rth->fd);
    29 }
    30
    31 int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
    32 {
    33 socklen_t addr_len;
    34
    35 memset(rth, 0, sizeof(rth));
    36
    37 rth->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
    38 if (rth->fd < 0) {
    39 bb_perror_msg("cannot open netlink socket");
    40 return -1;
    41 }
    42
    43 memset(&rth->local, 0, sizeof(rth->local));
    44 rth->local.nl_family = AF_NETLINK;
    45 rth->local.nl_groups = subscriptions;
    46
    47 if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) {
    48 bb_perror_msg("cannot bind netlink socket");
    49 return -1;
    50 }
    51 addr_len = sizeof(rth->local);
    52 if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) {
    53 bb_perror_msg("cannot getsockname");
    54 return -1;
    55 }
    56 if (addr_len != sizeof(rth->local)) {
    57 bb_error_msg("wrong address length %d", addr_len);
    58 return -1;
    59 }
    60 if (rth->local.nl_family != AF_NETLINK) {
    61 bb_error_msg("wrong address family %d", rth->local.nl_family);
    62 return -1;
    63 }
    64 rth->seq = time(NULL);
    65 return 0;
    66 }
    67
    68 int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
    69 {
    70 struct {
    71 struct nlmsghdr nlh;
    72 struct rtgenmsg g;
    73 } req;
    74 struct sockaddr_nl nladdr;
    75
    76 memset(&nladdr, 0, sizeof(nladdr));
    77 nladdr.nl_family = AF_NETLINK;
    78
    79 req.nlh.nlmsg_len = sizeof(req);
    80 req.nlh.nlmsg_type = type;
    81 req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
    82 req.nlh.nlmsg_pid = 0;
    83 req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
    84 req.g.rtgen_family = family;
    85
    86 return sendto(rth->fd, (void*)&req, sizeof(req), 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
    87 }
    88
    89 int rtnl_send(struct rtnl_handle *rth, char *buf, int len)
    90 {
    91 struct sockaddr_nl nladdr;
    92
    93 memset(&nladdr, 0, sizeof(nladdr));
    94 nladdr.nl_family = AF_NETLINK;
    95
    96 return sendto(rth->fd, buf, len, 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
    97 }
    98
    99 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
    100 {
    101 struct nlmsghdr nlh;
    102 struct sockaddr_nl nladdr;
    103 struct iovec iov[2] = { { &nlh, sizeof(nlh) }, { req, len } };
    104 struct msghdr msg = {
    105 (void*)&nladdr, sizeof(nladdr),
    106 iov, 2,
    107 NULL, 0,
    108 0
    109 };
    110
    111 memset(&nladdr, 0, sizeof(nladdr));
    112 nladdr.nl_family = AF_NETLINK;
    113
    114 nlh.nlmsg_len = NLMSG_LENGTH(len);
    115 nlh.nlmsg_type = type;
    116 nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
    117 nlh.nlmsg_pid = 0;
    118 nlh.nlmsg_seq = rth->dump = ++rth->seq;
    119
    120 return sendmsg(rth->fd, &msg, 0);
    121 }
    122
    123 int rtnl_dump_filter(struct rtnl_handle *rth,
    124 int (*filter)(struct sockaddr_nl *, struct nlmsghdr *n, void *),
    125 void *arg1,
    126 int (*junk)(struct sockaddr_nl *, struct nlmsghdr *n, void *),
    127 void *arg2)
    128 {
    129 char buf[8192];
    130 struct sockaddr_nl nladdr;
    131 struct iovec iov = { buf, sizeof(buf) };
    132
    133 while (1) {
    134 int status;
    135 struct nlmsghdr *h;
    136
    137 struct msghdr msg = {
    138 (void*)&nladdr, sizeof(nladdr),
    139 &iov, 1,
    140 NULL, 0,
    141 0
    142 };
    143
    144 status = recvmsg(rth->fd, &msg, 0);
    145
    146 if (status < 0) {
    147 if (errno == EINTR)
    148 continue;
    149 bb_perror_msg("OVERRUN");
    150 continue;
    151 }
    152 if (status == 0) {
    153 bb_error_msg("EOF on netlink");
    154 return -1;
    155 }
    156 if (msg.msg_namelen != sizeof(nladdr)) {
    157 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
    158 }
    159
    160 h = (struct nlmsghdr*)buf;
    161 while (NLMSG_OK(h, status)) {
    162 int err;
    163
    164 if (nladdr.nl_pid != 0 ||
    165 h->nlmsg_pid != rth->local.nl_pid ||
    166 h->nlmsg_seq != rth->dump) {
    167 if (junk) {
    168 err = junk(&nladdr, h, arg2);
    169 if (err < 0) {
    170 return err;
    171 }
    172 }
    173 goto skip_it;
    174 }
    175
    176 if (h->nlmsg_type == NLMSG_DONE) {
    177 return 0;
    178 }
    179 if (h->nlmsg_type == NLMSG_ERROR) {
    180 struct nlmsgerr *l_err = (struct nlmsgerr*)NLMSG_DATA(h);
    181 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
    182 bb_error_msg("ERROR truncated");
    183 } else {
    184 errno = -l_err->error;
    185 bb_perror_msg("RTNETLINK answers");
    186 }
    187 return -1;
    188 }
    189 err = filter(&nladdr, h, arg1);
    190 if (err < 0) {
    191 return err;
    192 }
    193
    194 skip_it:
    195 h = NLMSG_NEXT(h, status);
    196 }
    197 if (msg.msg_flags & MSG_TRUNC) {
    198 bb_error_msg("message truncated");
    199 continue;
    200 }
    201 if (status) {
    202 bb_error_msg_and_die("remnant of size %d!", status);
    203 }
    204 }
    205 }
    206
    207 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
    208 unsigned groups, struct nlmsghdr *answer,
    209 int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
    210 void *jarg)
    211 {
    212 int status;
    213 unsigned seq;
    214 struct nlmsghdr *h;
    215 struct sockaddr_nl nladdr;
    216 struct iovec iov = { (void*)n, n->nlmsg_len };
    217 char buf[8192];
    218 struct msghdr msg = {
    219 (void*)&nladdr, sizeof(nladdr),
    220 &iov, 1,
    221 NULL, 0,
    222 0
    223 };
    224
    225 memset(&nladdr, 0, sizeof(nladdr));
    226 nladdr.nl_family = AF_NETLINK;
    227 nladdr.nl_pid = peer;
    228 nladdr.nl_groups = groups;
    229
    230 n->nlmsg_seq = seq = ++rtnl->seq;
    231 if (answer == NULL) {
    232 n->nlmsg_flags |= NLM_F_ACK;
    233 }
    234 status = sendmsg(rtnl->fd, &msg, 0);
    235
    236 if (status < 0) {
    237 bb_perror_msg("cannot talk to rtnetlink");
    238 return -1;
    239 }
    240
    241 iov.iov_base = buf;
    242
    243 while (1) {
    244 iov.iov_len = sizeof(buf);
    245 status = recvmsg(rtnl->fd, &msg, 0);
    246
    247 if (status < 0) {
    248 if (errno == EINTR) {
    249 continue;
    250 }
    251 bb_perror_msg("OVERRUN");
    252 continue;
    253 }
    254 if (status == 0) {
    255 bb_error_msg("EOF on netlink");
    256 return -1;
    257 }
    258 if (msg.msg_namelen != sizeof(nladdr)) {
    259 bb_error_msg_and_die("sender address length == %d", msg.msg_namelen);
    260 }
    261 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
    262 int l_err;
    263 int len = h->nlmsg_len;
    264 int l = len - sizeof(*h);
    265
    266 if (l<0 || len>status) {
    267 if (msg.msg_flags & MSG_TRUNC) {
    268 bb_error_msg("truncated message");
    269 return -1;
    270 }
    271 bb_error_msg_and_die("malformed message: len=%d!", len);
    272 }
    273
    274 if (nladdr.nl_pid != peer ||
    275 h->nlmsg_pid != rtnl->local.nl_pid ||
    276 h->nlmsg_seq != seq) {
    277 if (junk) {
    278 l_err = junk(&nladdr, h, jarg);
    279 if (l_err < 0) {
    280 return l_err;
    281 }
    282 }
    283 continue;
    284 }
    285
    286 if (h->nlmsg_type == NLMSG_ERROR) {
    287 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
    288 if (l < sizeof(struct nlmsgerr)) {
    289 bb_error_msg("ERROR truncated");
    290 } else {
    291 errno = -err->error;
    292 if (errno == 0) {
    293 if (answer) {
    294 memcpy(answer, h, h->nlmsg_len);
    295 }
    296 return 0;
    297 }
    298 bb_perror_msg("RTNETLINK answers");
    299 }
    300 return -1;
    301 }
    302 if (answer) {
    303 memcpy(answer, h, h->nlmsg_len);
    304 return 0;
    305 }
    306
    307 bb_error_msg("unexpected reply!");
    308
    309 status -= NLMSG_ALIGN(len);
    310 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
    311 }
    312 if (msg.msg_flags & MSG_TRUNC) {
    313 bb_error_msg("message truncated");
    314 continue;
    315 }
    316 if (status) {
    317 bb_error_msg_and_die("remnant of size %d!", status);
    318 }
    319 }
    320 }
    321
    322 int addattr32(struct nlmsghdr *n, int maxlen, int type, uint32_t data)
    323 {
    324 int len = RTA_LENGTH(4);
    325 struct rtattr *rta;
    326 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
    327 return -1;
    328 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
    329 rta->rta_type = type;
    330 rta->rta_len = len;
    331 memcpy(RTA_DATA(rta), &data, 4);
    332 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
    333 return 0;
    334 }
    335
    336 int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen)
    337 {
    338 int len = RTA_LENGTH(alen);
    339 struct rtattr *rta;
    340
    341 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
    342 return -1;
    343 rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
    344 rta->rta_type = type;
    345 rta->rta_len = len;
    346 memcpy(RTA_DATA(rta), data, alen);
    347 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
    348 return 0;
    349 }
    350
    351 int rta_addattr32(struct rtattr *rta, int maxlen, int type, uint32_t data)
    352 {
    353 int len = RTA_LENGTH(4);
    354 struct rtattr *subrta;
    355
    356 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
    357 return -1;
    358 }
    359 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
    360 subrta->rta_type = type;
    361 subrta->rta_len = len;
    362 memcpy(RTA_DATA(subrta), &data, 4);
    363 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
    364 return 0;
    365 }
    366
    367 int rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen)
    368 {
    369 struct rtattr *subrta;
    370 int len = RTA_LENGTH(alen);
    371
    372 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
    373 return -1;
    374 }
    375 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
    376 subrta->rta_type = type;
    377 subrta->rta_len = len;
    378 memcpy(RTA_DATA(subrta), data, alen);
    379 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
    380 return 0;
    381 }
    382
    383
    384 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
    385 {
    386 while (RTA_OK(rta, len)) {
    387 if (rta->rta_type <= max) {
    388 tb[rta->rta_type] = rta;
    389 }
    390 rta = RTA_NEXT(rta,len);
    391 }
    392 if (len) {
    393 bb_error_msg("deficit %d, rta_len=%d!", len, rta->rta_len);
    394 }
    395 return 0;
    396 }