Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 1 | /* |
| 2 | * libipq.c |
| 3 | * |
| 4 | * IPQ userspace library. |
| 5 | * |
| 6 | * Please note that this library is still developmental, and there may |
| 7 | * be some API changes. |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation; either version 2 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | #include <stdlib.h> |
| 22 | #include <stdio.h> |
| 23 | #include <string.h> |
| 24 | #include <unistd.h> |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 25 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 26 | #include <libipq/libipq.h> |
| 27 | |
| 28 | /**************************************************************************** |
| 29 | * |
| 30 | * Private interface |
| 31 | * |
| 32 | ****************************************************************************/ |
| 33 | |
| 34 | enum { |
| 35 | IPQ_ERR_NONE = 0, |
| 36 | IPQ_ERR_IMPL, |
| 37 | IPQ_ERR_HANDLE, |
| 38 | IPQ_ERR_SOCKET, |
| 39 | IPQ_ERR_BIND, |
| 40 | IPQ_ERR_BUFFER, |
| 41 | IPQ_ERR_RECV, |
| 42 | IPQ_ERR_NLEOF, |
| 43 | IPQ_ERR_ADDRLEN, |
| 44 | IPQ_ERR_STRUNC, |
| 45 | IPQ_ERR_RTRUNC, |
| 46 | IPQ_ERR_NLRECV, |
| 47 | IPQ_ERR_SEND, |
| 48 | IPQ_ERR_SUPP, |
| 49 | IPQ_ERR_RECVBUF |
| 50 | }; |
| 51 | #define IPQ_MAXERR IPQ_ERR_RECVBUF |
| 52 | |
| 53 | struct ipq_errmap_t { |
| 54 | int errcode; |
| 55 | char *message; |
| 56 | } ipq_errmap[] = { |
| 57 | { IPQ_ERR_NONE, "Unknown error" }, |
| 58 | { IPQ_ERR_IMPL, "Implementation error" }, |
| 59 | { IPQ_ERR_HANDLE, "Unable to create netlink handle" }, |
| 60 | { IPQ_ERR_SOCKET, "Unable to create netlink socket" }, |
| 61 | { IPQ_ERR_BIND, "Unable to bind netlink socket" }, |
| 62 | { IPQ_ERR_BUFFER, "Unable to allocate buffer" }, |
| 63 | { IPQ_ERR_RECV, "Failed to receive netlink message" }, |
| 64 | { IPQ_ERR_NLEOF, "Received EOF on netlink socket" }, |
| 65 | { IPQ_ERR_ADDRLEN, "Invalid peer address length" }, |
| 66 | { IPQ_ERR_STRUNC, "Sent message truncated" }, |
| 67 | { IPQ_ERR_RTRUNC, "Received message truncated" }, |
| 68 | { IPQ_ERR_NLRECV, "Received error from netlink" }, |
| 69 | { IPQ_ERR_SEND, "Failed to send netlink message" }, |
| 70 | { IPQ_ERR_SUPP, "Operation not supported" }, |
| 71 | { IPQ_ERR_RECVBUF, "Receive buffer size invalid" } |
| 72 | }; |
| 73 | |
| 74 | static int ipq_errno = IPQ_ERR_NONE; |
| 75 | |
| 76 | static ssize_t ipq_netlink_sendto(const struct ipq_handle *h, |
| 77 | const void *msg, size_t len); |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 78 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 79 | static ssize_t ipq_netlink_recvfrom(const struct ipq_handle *h, |
| 80 | unsigned char *buf, size_t len); |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 81 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 82 | static ssize_t ipq_netlink_sendmsg(const struct ipq_handle *h, |
| 83 | const struct msghdr *msg, |
| 84 | unsigned int flags); |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 85 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 86 | static char *ipq_strerror(int errcode); |
| 87 | |
| 88 | static ssize_t ipq_netlink_sendto(const struct ipq_handle *h, |
| 89 | const void *msg, size_t len) |
| 90 | { |
| 91 | int status = sendto(h->fd, msg, len, 0, |
| 92 | (struct sockaddr *)&h->peer, sizeof(h->peer)); |
| 93 | if (status < 0) |
| 94 | ipq_errno = IPQ_ERR_SEND; |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 95 | return status; |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 96 | } |
| 97 | |
| 98 | static ssize_t ipq_netlink_sendmsg(const struct ipq_handle *h, |
| 99 | const struct msghdr *msg, |
| 100 | unsigned int flags) |
| 101 | { |
| 102 | int status = sendmsg(h->fd, msg, flags); |
| 103 | if (status < 0) |
| 104 | ipq_errno = IPQ_ERR_SEND; |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 105 | return status; |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 106 | } |
| 107 | |
| 108 | static ssize_t ipq_netlink_recvfrom(const struct ipq_handle *h, |
| 109 | unsigned char *buf, size_t len) |
| 110 | { |
| 111 | int addrlen, status; |
| 112 | struct nlmsghdr *nlh; |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 113 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 114 | if (len < sizeof(struct nlmsgerr)) { |
| 115 | ipq_errno = IPQ_ERR_RECVBUF; |
| 116 | return -1; |
| 117 | } |
| 118 | addrlen = sizeof(h->peer); |
| 119 | status = recvfrom(h->fd, buf, len, 0, |
| 120 | (struct sockaddr *)&h->peer, &addrlen); |
| 121 | if (status < 0) { |
| 122 | ipq_errno = IPQ_ERR_RECV; |
| 123 | return status; |
| 124 | } |
| 125 | if (addrlen != sizeof(h->peer)) { |
| 126 | ipq_errno = IPQ_ERR_RECV; |
| 127 | return -1; |
| 128 | } |
| 129 | if (status == 0) { |
| 130 | ipq_errno = IPQ_ERR_NLEOF; |
| 131 | return -1; |
| 132 | } |
| 133 | nlh = (struct nlmsghdr *)buf; |
| 134 | if (nlh->nlmsg_flags & MSG_TRUNC || nlh->nlmsg_len > status) { |
| 135 | ipq_errno = IPQ_ERR_RTRUNC; |
| 136 | return -1; |
| 137 | } |
| 138 | return status; |
| 139 | } |
| 140 | |
| 141 | static char *ipq_strerror(int errcode) |
| 142 | { |
| 143 | if (errcode < 0 || errcode > IPQ_MAXERR) |
| 144 | errcode = IPQ_ERR_IMPL; |
| 145 | return ipq_errmap[errcode].message; |
| 146 | } |
| 147 | |
| 148 | /**************************************************************************** |
| 149 | * |
| 150 | * Public interface |
| 151 | * |
| 152 | ****************************************************************************/ |
| 153 | |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 154 | /* |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 155 | * Create and initialise an ipq handle. |
| 156 | * FIXME: implement flags. |
| 157 | */ |
| 158 | struct ipq_handle *ipq_create_handle(u_int32_t flags) |
| 159 | { |
| 160 | int status; |
| 161 | struct ipq_handle *h; |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 162 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 163 | h = (struct ipq_handle *)malloc(sizeof(struct ipq_handle)); |
| 164 | if (h == NULL) { |
| 165 | ipq_errno = IPQ_ERR_HANDLE; |
| 166 | return NULL; |
| 167 | } |
| 168 | memset(h, 0, sizeof(struct ipq_handle)); |
| 169 | h->fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_FIREWALL); |
| 170 | if (h->fd == -1) { |
| 171 | ipq_errno = IPQ_ERR_SOCKET; |
| 172 | close(h->fd); |
| 173 | free(h); |
| 174 | return NULL; |
| 175 | } |
| 176 | memset(&h->local, 0, sizeof(struct sockaddr_nl)); |
| 177 | h->local.nl_family = AF_NETLINK; |
| 178 | h->local.nl_pid = getpid(); |
| 179 | h->local.nl_groups = 0; |
| 180 | status = bind(h->fd, (struct sockaddr *)&h->local, sizeof(h->local)); |
| 181 | if (status == -1) { |
| 182 | ipq_errno = IPQ_ERR_BIND; |
| 183 | close(h->fd); |
| 184 | free(h); |
| 185 | return NULL; |
| 186 | } |
| 187 | memset(&h->peer, 0, sizeof(struct sockaddr_nl)); |
| 188 | h->peer.nl_family = AF_NETLINK; |
| 189 | h->peer.nl_pid = 0; |
| 190 | h->peer.nl_groups = 0; |
| 191 | return h; |
| 192 | } |
| 193 | |
| 194 | /* |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 195 | * No error condition is checked here at this stage, but it may happen |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 196 | * if/when reliable messaging is implemented. |
| 197 | */ |
| 198 | int ipq_destroy_handle(struct ipq_handle *h) |
| 199 | { |
| 200 | if (h) { |
| 201 | close(h->fd); |
| 202 | free(h); |
| 203 | } |
| 204 | return 0; |
| 205 | } |
| 206 | |
| 207 | int ipq_set_mode(const struct ipq_handle *h, |
| 208 | u_int8_t mode, size_t range) |
| 209 | { |
| 210 | struct { |
| 211 | struct nlmsghdr nlh; |
| 212 | ipq_peer_msg_t pm; |
| 213 | } req; |
Rusty Russell | 7e53bf9 | 2000-03-20 07:03:28 +0000 | [diff] [blame] | 214 | |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 215 | memset(&req, 0, sizeof(req)); |
| 216 | req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(req)); |
| 217 | req.nlh.nlmsg_flags = NLM_F_REQUEST; |
| 218 | req.nlh.nlmsg_type = IPQM_MODE; |
| 219 | req.nlh.nlmsg_pid = h->local.nl_pid; |
| 220 | req.pm.msg.mode.value = mode; |
| 221 | req.pm.msg.mode.range = range; |
| 222 | return ipq_netlink_sendto(h, (void *)&req, req.nlh.nlmsg_len); |
| 223 | } |
| 224 | |
| 225 | /* Note: timeout is not yet implemented */ |
| 226 | ssize_t ipq_read(const struct ipq_handle *h, |
| 227 | unsigned char *buf, size_t len, int timeout) |
| 228 | { |
| 229 | return ipq_netlink_recvfrom(h, buf, len); |
| 230 | } |
| 231 | |
| 232 | int ipq_message_type(const unsigned char *buf) |
| 233 | { |
| 234 | return ((struct nlmsghdr*)buf)->nlmsg_type; |
| 235 | } |
| 236 | |
| 237 | int ipq_get_msgerr(const unsigned char *buf) |
| 238 | { |
| 239 | struct nlmsghdr *h = (struct nlmsghdr *)buf; |
| 240 | struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h); |
| 241 | return -err->error; |
| 242 | } |
| 243 | |
| 244 | ipq_packet_msg_t *ipq_get_packet(const unsigned char *buf) |
| 245 | { |
| 246 | return NLMSG_DATA((struct nlmsghdr *)(buf)); |
| 247 | } |
| 248 | |
| 249 | int ipq_set_verdict(const struct ipq_handle *h, |
| 250 | unsigned long id, |
| 251 | unsigned int verdict, |
| 252 | size_t data_len, |
| 253 | unsigned char *buf) |
| 254 | { |
| 255 | unsigned char nvecs; |
| 256 | size_t tlen; |
| 257 | struct nlmsghdr nlh; |
| 258 | ipq_peer_msg_t pm; |
| 259 | struct iovec iov[3]; |
| 260 | struct msghdr msg; |
| 261 | |
| 262 | memset(&nlh, 0, sizeof(nlh)); |
| 263 | nlh.nlmsg_flags = NLM_F_REQUEST; |
| 264 | nlh.nlmsg_type = IPQM_VERDICT; |
| 265 | nlh.nlmsg_pid = h->local.nl_pid; |
| 266 | memset(&pm, 0, sizeof(pm)); |
| 267 | pm.msg.verdict.value = verdict; |
| 268 | pm.msg.verdict.id = id; |
| 269 | pm.msg.verdict.data_len = data_len; |
| 270 | iov[0].iov_base = &nlh; |
| 271 | iov[0].iov_len = sizeof(nlh); |
| 272 | iov[1].iov_base = ± |
| 273 | iov[1].iov_len = sizeof(pm); |
| 274 | tlen = sizeof(nlh) + sizeof(pm); |
| 275 | nvecs = 2; |
| 276 | if (data_len && buf) { |
| 277 | iov[2].iov_base = buf; |
| 278 | iov[2].iov_len = data_len; |
| 279 | tlen += data_len; |
| 280 | nvecs++; |
| 281 | } |
| 282 | msg.msg_name = (void *)&h->peer; |
| 283 | msg.msg_namelen = sizeof(h->peer); |
| 284 | msg.msg_iov = iov; |
| 285 | msg.msg_iovlen = nvecs; |
| 286 | msg.msg_control = NULL; |
| 287 | msg.msg_controllen = 0; |
| 288 | msg.msg_flags = 0; |
| 289 | nlh.nlmsg_len = tlen; |
| 290 | return ipq_netlink_sendmsg(h, &msg, 0); |
| 291 | } |
| 292 | |
| 293 | /* Not implemented yet */ |
| 294 | int ipq_ctl(const struct ipq_handle *h, int request, ...) |
| 295 | { |
| 296 | return 1; |
| 297 | } |
| 298 | |
| 299 | void ipq_perror(const char *s) |
| 300 | { |
| 301 | if (s) |
| 302 | fputs(s, stderr); |
| 303 | else |
| 304 | fputs("ERROR", stderr); |
| 305 | if (ipq_errno) |
| 306 | fprintf(stderr, ": %s", ipq_strerror(ipq_errno)); |
| 307 | if (errno) |
| 308 | fprintf(stderr, ": %s", strerror(errno)); |
| 309 | fputc('\n', stderr); |
| 310 | } |