Frank Maker | ed6b39c | 2011-05-23 21:14:58 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | /* NOTICE: This is a clean room re-implementation of libnl */ |
| 18 | |
| 19 | #include <errno.h> |
| 20 | #include <unistd.h> |
| 21 | #include <stdio.h> |
| 22 | #include <sys/time.h> |
Elliott Hughes | b77d3d7 | 2012-09-11 18:52:40 -0700 | [diff] [blame] | 23 | #include <sys/socket.h> |
Frank Maker | ed6b39c | 2011-05-23 21:14:58 -0700 | [diff] [blame] | 24 | #include <linux/netlink.h> |
Dmitry Shmidt | 2d9a628 | 2012-07-10 10:48:38 -0700 | [diff] [blame] | 25 | #include <netlink/genl/ctrl.h> |
| 26 | #include <netlink/genl/family.h> |
Frank Maker | ed6b39c | 2011-05-23 21:14:58 -0700 | [diff] [blame] | 27 | #include "netlink-types.h" |
| 28 | |
| 29 | /* Get head of attribute data. */ |
| 30 | struct nlattr *genlmsg_attrdata(const struct genlmsghdr *gnlh, int hdrlen) |
| 31 | { |
| 32 | return (struct nlattr *) \ |
| 33 | ((char *) gnlh + GENL_HDRLEN + NLMSG_ALIGN(hdrlen)); |
| 34 | |
| 35 | } |
| 36 | |
| 37 | /* Get length of attribute data. */ |
| 38 | int genlmsg_attrlen(const struct genlmsghdr *gnlh, int hdrlen) |
| 39 | { |
| 40 | struct nlattr *nla; |
| 41 | struct nlmsghdr *nlh; |
| 42 | |
| 43 | nla = genlmsg_attrdata(gnlh, hdrlen); |
| 44 | nlh = (struct nlmsghdr *) ((char *) gnlh - NLMSG_HDRLEN); |
| 45 | return (char *) nlmsg_tail(nlh) - (char *) nla; |
| 46 | } |
| 47 | |
| 48 | /* Add generic netlink header to netlink message. */ |
| 49 | void *genlmsg_put(struct nl_msg *msg, uint32_t pid, uint32_t seq, int family, |
| 50 | int hdrlen, int flags, uint8_t cmd, uint8_t version) |
| 51 | { |
| 52 | int new_size; |
| 53 | struct nlmsghdr *nlh; |
| 54 | struct timeval tv; |
| 55 | struct genlmsghdr *gmh; |
| 56 | |
| 57 | /* Make sure nl_msg has enough space */ |
| 58 | new_size = NLMSG_HDRLEN + GENL_HDRLEN + hdrlen; |
| 59 | if ((sizeof(struct nl_msg) + new_size) > msg->nm_size) |
| 60 | goto fail; |
| 61 | |
| 62 | /* Fill in netlink header */ |
| 63 | nlh = msg->nm_nlh; |
| 64 | nlh->nlmsg_len = new_size; |
| 65 | nlh->nlmsg_type = family; |
| 66 | nlh->nlmsg_pid = getpid(); |
| 67 | nlh->nlmsg_flags = flags | NLM_F_REQUEST | NLM_F_ACK; |
| 68 | |
| 69 | /* Get current time for sequence number */ |
| 70 | if (gettimeofday(&tv, NULL)) |
| 71 | nlh->nlmsg_seq = 1; |
| 72 | else |
| 73 | nlh->nlmsg_seq = (int) tv.tv_sec; |
| 74 | |
| 75 | /* Setup genlmsghdr in new message */ |
| 76 | gmh = (struct genlmsghdr *) ((char *)nlh + NLMSG_HDRLEN); |
| 77 | gmh->cmd = (__u8) cmd; |
| 78 | gmh->version = version; |
| 79 | |
| 80 | return gmh; |
| 81 | fail: |
| 82 | return NULL; |
| 83 | |
| 84 | } |
| 85 | |
| 86 | /* Socket has already been alloced to connect it to kernel? */ |
| 87 | int genl_connect(struct nl_sock *sk) |
| 88 | { |
| 89 | return nl_connect(sk, NETLINK_GENERIC); |
| 90 | |
| 91 | } |
| 92 | |
| 93 | int genl_ctrl_alloc_cache(struct nl_sock *sock, struct nl_cache **result) |
| 94 | { |
| 95 | int rc = -1; |
| 96 | int nl80211_genl_id = -1; |
| 97 | char sendbuf[sizeof(struct nlmsghdr)+sizeof(struct genlmsghdr)]; |
| 98 | struct nlmsghdr nlmhdr; |
| 99 | struct genlmsghdr gmhhdr; |
| 100 | struct iovec sendmsg_iov; |
| 101 | struct msghdr msg; |
| 102 | int num_char; |
| 103 | const int RECV_BUF_SIZE = getpagesize(); |
| 104 | char *recvbuf; |
| 105 | struct iovec recvmsg_iov; |
| 106 | int nl80211_flag = 0, nlm_f_multi = 0, nlmsg_done = 0; |
| 107 | struct nlmsghdr *nlh; |
| 108 | |
| 109 | /* REQUEST GENERIC NETLINK FAMILY ID */ |
| 110 | /* Message buffer */ |
| 111 | nlmhdr.nlmsg_len = sizeof(sendbuf); |
| 112 | nlmhdr.nlmsg_type = NETLINK_GENERIC; |
| 113 | nlmhdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP; |
| 114 | nlmhdr.nlmsg_seq = sock->s_seq_next; |
| 115 | nlmhdr.nlmsg_pid = sock->s_local.nl_pid; |
| 116 | |
| 117 | /* Generic netlink header */ |
Dmitry Shmidt | e5de9ee | 2011-09-30 12:39:48 -0700 | [diff] [blame] | 118 | memset(&gmhhdr, 0, sizeof(gmhhdr)); |
Frank Maker | ed6b39c | 2011-05-23 21:14:58 -0700 | [diff] [blame] | 119 | gmhhdr.cmd = CTRL_CMD_GETFAMILY; |
| 120 | gmhhdr.version = CTRL_ATTR_FAMILY_ID; |
| 121 | |
| 122 | /* Combine netlink and generic netlink headers */ |
| 123 | memcpy(&sendbuf[0], &nlmhdr, sizeof(nlmhdr)); |
| 124 | memcpy(&sendbuf[0]+sizeof(nlmhdr), &gmhhdr, sizeof(gmhhdr)); |
| 125 | |
| 126 | /* Create IO vector with Netlink message */ |
| 127 | sendmsg_iov.iov_base = &sendbuf; |
| 128 | sendmsg_iov.iov_len = sizeof(sendbuf); |
| 129 | |
| 130 | /* Socket message */ |
| 131 | msg.msg_name = (void *) &sock->s_peer; |
| 132 | msg.msg_namelen = sizeof(sock->s_peer); |
| 133 | msg.msg_iov = &sendmsg_iov; |
| 134 | msg.msg_iovlen = 1; /* Only sending one iov */ |
| 135 | msg.msg_control = NULL; |
| 136 | msg.msg_controllen = 0; |
| 137 | msg.msg_flags = 0; |
| 138 | |
| 139 | /* Send message and verify sent */ |
| 140 | num_char = sendmsg(sock->s_fd, &msg, 0); |
| 141 | if (num_char == -1) |
| 142 | return -errno; |
| 143 | |
| 144 | /* RECEIVE GENL CMD RESPONSE */ |
| 145 | |
| 146 | /* Create receive iov buffer */ |
| 147 | recvbuf = (char *) malloc(RECV_BUF_SIZE); |
| 148 | |
| 149 | /* Attach to iov */ |
| 150 | recvmsg_iov.iov_base = recvbuf; |
| 151 | recvmsg_iov.iov_len = RECV_BUF_SIZE; |
| 152 | |
| 153 | msg.msg_iov = &recvmsg_iov; |
| 154 | msg.msg_iovlen = 1; |
| 155 | |
| 156 | /***************************************************************/ |
| 157 | /* Receive message. If multipart message, keep receiving until */ |
| 158 | /* message type is NLMSG_DONE */ |
| 159 | /***************************************************************/ |
| 160 | |
| 161 | do { |
| 162 | |
| 163 | int recvmsg_len, nlmsg_rem; |
| 164 | |
| 165 | /* Receive message */ |
| 166 | memset(recvbuf, 0, RECV_BUF_SIZE); |
| 167 | recvmsg_len = recvmsg(sock->s_fd, &msg, 0); |
| 168 | |
| 169 | /* Make sure receive successful */ |
| 170 | if (recvmsg_len < 0) { |
| 171 | rc = -errno; |
| 172 | goto error_recvbuf; |
| 173 | } |
| 174 | |
| 175 | /* Parse nlmsghdr */ |
| 176 | nlmsg_for_each_msg(nlh, (struct nlmsghdr *) recvbuf, \ |
| 177 | recvmsg_len, nlmsg_rem) { |
| 178 | struct nlattr *nla; |
| 179 | int nla_rem; |
| 180 | |
| 181 | /* Check type */ |
| 182 | switch (nlh->nlmsg_type) { |
| 183 | case NLMSG_DONE: |
| 184 | goto return_genl_id; |
| 185 | break; |
| 186 | case NLMSG_ERROR: |
| 187 | |
| 188 | /* Should check nlmsgerr struct received */ |
| 189 | fprintf(stderr, "Receive message error\n"); |
| 190 | goto error_recvbuf; |
| 191 | case NLMSG_OVERRUN: |
| 192 | fprintf(stderr, "Receive data partly lost\n"); |
| 193 | goto error_recvbuf; |
| 194 | case NLMSG_MIN_TYPE: |
| 195 | case NLMSG_NOOP: |
| 196 | break; |
| 197 | default: |
| 198 | break; |
| 199 | } |
| 200 | |
| 201 | |
| 202 | |
| 203 | /* Check flags */ |
| 204 | if (nlh->nlmsg_flags & NLM_F_MULTI) |
| 205 | nlm_f_multi = 1; |
| 206 | else |
| 207 | nlm_f_multi = 0; |
| 208 | |
| 209 | if (nlh->nlmsg_type & NLMSG_DONE) |
| 210 | nlmsg_done = 1; |
| 211 | else |
| 212 | nlmsg_done = 0; |
| 213 | |
| 214 | /* Iteratve over attributes */ |
| 215 | nla_for_each_attr(nla, |
| 216 | nlmsg_attrdata(nlh, GENL_HDRLEN), |
| 217 | nlmsg_attrlen(nlh, GENL_HDRLEN), |
| 218 | nla_rem){ |
| 219 | |
| 220 | /* If this family is nl80211 */ |
| 221 | if (nla->nla_type == CTRL_ATTR_FAMILY_NAME && |
| 222 | !strcmp((char *)nla_data(nla), |
| 223 | "nl80211")) |
| 224 | nl80211_flag = 1; |
| 225 | |
| 226 | /* Save the family id */ |
| 227 | else if (nl80211_flag && |
Dmitry Shmidt | e5de9ee | 2011-09-30 12:39:48 -0700 | [diff] [blame] | 228 | nla->nla_type == CTRL_ATTR_FAMILY_ID) { |
| 229 | nl80211_genl_id = |
Frank Maker | ed6b39c | 2011-05-23 21:14:58 -0700 | [diff] [blame] | 230 | *((int *)nla_data(nla)); |
Dmitry Shmidt | e5de9ee | 2011-09-30 12:39:48 -0700 | [diff] [blame] | 231 | nl80211_flag = 0; |
| 232 | } |
Frank Maker | ed6b39c | 2011-05-23 21:14:58 -0700 | [diff] [blame] | 233 | |
| 234 | } |
| 235 | |
| 236 | } |
| 237 | |
| 238 | } while (nlm_f_multi && !nlmsg_done); |
| 239 | |
| 240 | return_genl_id: |
| 241 | /* Return family id as cache pointer */ |
| 242 | *result = (struct nl_cache *) nl80211_genl_id; |
| 243 | rc = 0; |
| 244 | error_recvbuf: |
| 245 | free(recvbuf); |
| 246 | error: |
| 247 | return rc; |
| 248 | } |
| 249 | |
| 250 | /* Checks the netlink cache to find family reference by name string */ |
| 251 | /* NOTE: Caller needs to call genl_family_put() when done with * |
| 252 | * returned object */ |
| 253 | struct genl_family *genl_ctrl_search_by_name(struct nl_cache *cache, \ |
| 254 | const char *name) |
| 255 | { |
Frank Maker | ed6b39c | 2011-05-23 21:14:58 -0700 | [diff] [blame] | 256 | struct genl_family *gf = (struct genl_family *) \ |
| 257 | malloc(sizeof(struct genl_family)); |
| 258 | if (!gf) |
| 259 | goto fail; |
| 260 | memset(gf, 0, sizeof(*gf)); |
| 261 | |
| 262 | /* Add ref */ |
| 263 | gf->ce_refcnt++; |
| 264 | |
| 265 | /* Overriding cache pointer as family id for now */ |
| 266 | gf->gf_id = (uint16_t) ((uint32_t) cache); |
Dmitry Shmidt | 2d9a628 | 2012-07-10 10:48:38 -0700 | [diff] [blame] | 267 | strncpy(gf->gf_name, name, GENL_NAMSIZ); |
Frank Maker | ed6b39c | 2011-05-23 21:14:58 -0700 | [diff] [blame] | 268 | |
| 269 | return gf; |
| 270 | fail: |
| 271 | return NULL; |
| 272 | |
| 273 | } |
| 274 | |
| 275 | int genl_ctrl_resolve(struct nl_sock *sk, const char *name) |
| 276 | { |
Dmitry Shmidt | 2d9a628 | 2012-07-10 10:48:38 -0700 | [diff] [blame] | 277 | struct nl_cache *cache = NULL; |
| 278 | struct genl_family *gf = NULL; |
| 279 | int id = -1; |
| 280 | |
Frank Maker | ed6b39c | 2011-05-23 21:14:58 -0700 | [diff] [blame] | 281 | /* Hack to support wpa_supplicant */ |
| 282 | if (strcmp(name, "nlctrl") == 0) |
| 283 | return NETLINK_GENERIC; |
Dmitry Shmidt | 2d9a628 | 2012-07-10 10:48:38 -0700 | [diff] [blame] | 284 | |
| 285 | if (strcmp(name, "nl80211") != 0) { |
| 286 | fprintf(stderr, "%s is not supported\n", name); |
| 287 | return id; |
Frank Maker | ed6b39c | 2011-05-23 21:14:58 -0700 | [diff] [blame] | 288 | } |
| 289 | |
Dmitry Shmidt | 2d9a628 | 2012-07-10 10:48:38 -0700 | [diff] [blame] | 290 | if (!genl_ctrl_alloc_cache(sk, &cache)) { |
| 291 | gf = genl_ctrl_search_by_name(cache, name); |
| 292 | if (gf) |
| 293 | id = genl_family_get_id(gf); |
| 294 | } |
Frank Maker | ed6b39c | 2011-05-23 21:14:58 -0700 | [diff] [blame] | 295 | |
Dmitry Shmidt | 2d9a628 | 2012-07-10 10:48:38 -0700 | [diff] [blame] | 296 | if (gf) |
| 297 | genl_family_put(gf); |
| 298 | if (cache) |
| 299 | nl_cache_free(cache); |
| 300 | |
| 301 | return id; |
| 302 | } |