2 * DHCP library with GLib integration
4 * Copyright (C) 2007-2013 Intel Corporation. All rights reserved.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
29 #include <sys/ioctl.h>
33 #include <net/if_arp.h>
35 #include <netpacket/packet.h>
36 #include <net/ethernet.h>
37 #include <arpa/inet.h>
42 #include "../src/connman.h"
44 static const DHCPOption client_options[] = {
45 { OPTION_IP, 0x01 }, /* subnet-mask */
46 { OPTION_IP | OPTION_LIST, 0x03 }, /* routers */
47 { OPTION_IP | OPTION_LIST, 0x06 }, /* domain-name-servers */
48 { OPTION_STRING, 0x0c }, /* hostname */
49 { OPTION_STRING, 0x0f }, /* domain-name */
50 { OPTION_U16, 0x1a }, /* mtu */
51 { OPTION_IP | OPTION_LIST, 0x2a }, /* ntp-servers */
52 { OPTION_U32, 0x33 }, /* dhcp-lease-time */
53 /* Options below will not be exposed to user */
54 { OPTION_IP, 0x32 }, /* requested-ip */
55 { OPTION_U8, 0x35 }, /* message-type */
56 { OPTION_U32, 0x36 }, /* server-id */
57 { OPTION_U16, 0x39 }, /* max-size */
58 { OPTION_STRING, 0x3c }, /* vendor */
59 { OPTION_STRING, 0x3d }, /* client-id */
60 { OPTION_STRING, 0xfc }, /* UNOFFICIAL proxy-pac */
61 { OPTION_UNKNOWN, 0x00 },
64 GDHCPOptionType dhcp_get_code_type(uint8_t code)
68 for (i = 0; client_options[i].code; i++) {
69 if (client_options[i].code == code)
70 return client_options[i].type;
73 return OPTION_UNKNOWN;
76 uint8_t *dhcp_get_option(struct dhcp_packet *packet, int code)
82 /* option bytes: [code][len][data1][data2]..[dataLEN] */
83 optionptr = packet->options;
84 rem = sizeof(packet->options);
88 /* Bad packet, malformed option field */
91 if (optionptr[OPT_CODE] == DHCP_PADDING) {
98 if (optionptr[OPT_CODE] == DHCP_END) {
99 if (overload & FILE_FIELD) {
100 overload &= ~FILE_FIELD;
102 optionptr = packet->file;
103 rem = sizeof(packet->file);
106 } else if (overload & SNAME_FIELD) {
107 overload &= ~SNAME_FIELD;
109 optionptr = packet->sname;
110 rem = sizeof(packet->sname);
118 len = 2 + optionptr[OPT_LEN];
122 continue; /* complain and return NULL */
124 if (optionptr[OPT_CODE] == code)
125 return optionptr + OPT_DATA;
127 if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD)
128 overload |= optionptr[OPT_DATA];
136 int dhcp_end_option(uint8_t *optionptr)
140 while (optionptr[i] != DHCP_END) {
141 if (optionptr[i] != DHCP_PADDING)
142 i += optionptr[i + OPT_LEN] + OPT_DATA - 1;
150 uint8_t *dhcpv6_get_option(struct dhcpv6_packet *packet, uint16_t pkt_len,
151 int code, uint16_t *option_len, int *option_count)
154 uint8_t *optionptr, *found = NULL;
155 uint16_t opt_code, opt_len, len;
157 optionptr = packet->options;
158 rem = pkt_len - 1 - 3;
164 opt_code = optionptr[0] << 8 | optionptr[1];
165 opt_len = len = optionptr[2] << 8 | optionptr[3];
166 len += 2 + 2; /* skip code and len */
175 if (opt_code == code) {
177 *option_len = opt_len;
178 found = optionptr + 2 + 2;
189 *option_count = count;
201 uint8_t *dhcpv6_get_sub_option(unsigned char *option, uint16_t max_len,
202 uint16_t *option_code, uint16_t *option_len)
207 rem = max_len - 2 - 2;
213 code = option[0] << 8 | option[1];
214 len = option[2] << 8 | option[3];
227 * Add an option (supplied in binary form) to the options.
228 * Option format: [code][len][data1][data2]..[dataLEN]
230 void dhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
233 uint8_t *optionptr = packet->options;
234 unsigned end = dhcp_end_option(optionptr);
236 len = OPT_DATA + addopt[OPT_LEN];
238 /* end position + (option code/length + addopt length) + end option */
239 if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE)
240 /* option did not fit into the packet */
243 memcpy(optionptr + end, addopt, len);
245 optionptr[end + len] = DHCP_END;
249 * Add an option (supplied in binary form) to the options.
250 * Option format: [code][len][data1][data2]..[dataLEN]
252 void dhcpv6_add_binary_option(struct dhcpv6_packet *packet, uint16_t max_len,
253 uint16_t *pkt_len, uint8_t *addopt)
256 uint8_t *optionptr = packet->options;
258 len = 2 + 2 + (addopt[2] << 8 | addopt[3]);
260 /* end position + (option code/length + addopt length) */
261 if (*pkt_len + len >= max_len)
262 /* option did not fit into the packet */
265 memcpy(optionptr + *pkt_len, addopt, len);
269 static GDHCPOptionType check_option(uint8_t code, uint8_t data_len)
271 GDHCPOptionType type = dhcp_get_code_type(code);
274 if (type == OPTION_UNKNOWN)
277 len = dhcp_option_lengths[type & OPTION_TYPE_MASK];
278 if (len != data_len) {
279 printf("Invalid option len %d (expecting %d) for code 0x%x\n",
280 data_len, len, code);
281 return OPTION_UNKNOWN;
287 void dhcp_add_option_uint32(struct dhcp_packet *packet, uint8_t code,
292 if (check_option(code, sizeof(data)) == OPTION_UNKNOWN)
295 option[OPT_CODE] = code;
296 option[OPT_LEN] = sizeof(data);
297 put_be32(data, option + OPT_DATA);
299 dhcp_add_binary_option(packet, option);
302 void dhcp_add_option_uint16(struct dhcp_packet *packet, uint8_t code,
307 if (check_option(code, sizeof(data)) == OPTION_UNKNOWN)
310 option[OPT_CODE] = code;
311 option[OPT_LEN] = sizeof(data);
312 put_be16(data, option + OPT_DATA);
314 dhcp_add_binary_option(packet, option);
317 void dhcp_add_option_uint8(struct dhcp_packet *packet, uint8_t code,
322 if (check_option(code, sizeof(data)) == OPTION_UNKNOWN)
325 option[OPT_CODE] = code;
326 option[OPT_LEN] = sizeof(data);
327 option[OPT_DATA] = data;
329 dhcp_add_binary_option(packet, option);
332 void dhcp_init_header(struct dhcp_packet *packet, char type)
334 memset(packet, 0, sizeof(*packet));
336 packet->op = BOOTREQUEST;
342 packet->op = BOOTREPLY;
347 packet->cookie = htonl(DHCP_MAGIC);
348 packet->options[0] = DHCP_END;
350 dhcp_add_option_uint8(packet, DHCP_MESSAGE_TYPE, type);
353 void dhcpv6_init_header(struct dhcpv6_packet *packet, uint8_t type)
358 memset(packet, 0, sizeof(*packet));
360 packet->message = type;
362 __connman_util_get_random(&rand);
365 packet->transaction_id[0] = (id >> 16) & 0xff;
366 packet->transaction_id[1] = (id >> 8) & 0xff;
367 packet->transaction_id[2] = id & 0xff;
370 int dhcp_recv_l3_packet(struct dhcp_packet *packet, int fd)
374 memset(packet, 0, sizeof(*packet));
376 n = read(fd, packet, sizeof(*packet));
380 if (packet->cookie != htonl(DHCP_MAGIC))
386 int dhcpv6_recv_l3_packet(struct dhcpv6_packet **packet, unsigned char *buf,
391 n = read(fd, buf, buf_len);
395 *packet = (struct dhcpv6_packet *)buf;
400 /* TODO: Use glib checksum */
401 uint16_t dhcp_checksum(void *addr, int count)
404 * Compute Internet Checksum for "count" bytes
405 * beginning at location "addr".
408 uint16_t *source = (uint16_t *) addr;
411 /* This is the inner loop */
416 /* Add left-over byte, if any */
418 /* Make sure that the left-over byte is added correctly both
419 * with little and big endian hosts */
421 *(uint8_t *) &tmp = *(uint8_t *) source;
424 /* Fold 32-bit sum to 16 bits */
426 sum = (sum & 0xffff) + (sum >> 16);
431 #define IN6ADDR_ALL_DHCP_RELAY_AGENTS_AND_SERVERS_MC_INIT \
432 { { { 0xff,0x02,0,0,0,0,0,0,0,0,0,0,0,0x1,0,0x2 } } } /* ff02::1:2 */
433 static const struct in6_addr in6addr_all_dhcp_relay_agents_and_servers_mc =
434 IN6ADDR_ALL_DHCP_RELAY_AGENTS_AND_SERVERS_MC_INIT;
436 int dhcpv6_send_packet(int index, struct dhcpv6_packet *dhcp_pkt, int len)
440 struct in6_pktinfo *pktinfo;
441 struct cmsghdr *cmsg;
442 int fd, ret, opt = 1;
443 struct sockaddr_in6 src;
444 struct sockaddr_in6 dst;
446 size_t control_buf_len;
448 fd = socket(PF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
452 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
458 memset(&src, 0, sizeof(src));
459 src.sin6_family = AF_INET6;
460 src.sin6_port = htons(DHCPV6_CLIENT_PORT);
462 if (bind(fd, (struct sockaddr *) &src, sizeof(src)) <0) {
468 memset(&dst, 0, sizeof(dst));
469 dst.sin6_family = AF_INET6;
470 dst.sin6_port = htons(DHCPV6_SERVER_PORT);
472 dst.sin6_addr = in6addr_all_dhcp_relay_agents_and_servers_mc;
474 control_buf_len = CMSG_SPACE(sizeof(struct in6_pktinfo));
475 control_buf = g_try_malloc0(control_buf_len);
481 memset(&m, 0, sizeof(m));
482 memset(&v, 0, sizeof(v));
485 m.msg_namelen = sizeof(dst);
487 v.iov_base = (char *)dhcp_pkt;
492 m.msg_control = control_buf;
493 m.msg_controllen = control_buf_len;
494 cmsg = CMSG_FIRSTHDR(&m);
495 cmsg->cmsg_level = IPPROTO_IPV6;
496 cmsg->cmsg_type = IPV6_PKTINFO;
497 cmsg->cmsg_len = CMSG_LEN(sizeof(*pktinfo));
499 pktinfo = (struct in6_pktinfo *)CMSG_DATA(cmsg);
500 memset(pktinfo, 0, sizeof(*pktinfo));
501 pktinfo->ipi6_ifindex = index;
502 m.msg_controllen = cmsg->cmsg_len;
504 ret = sendmsg(fd, &m, 0);
506 char *msg = "DHCPv6 msg send failed";
508 if (errno == EADDRNOTAVAIL) {
509 char *str = g_strdup_printf("%s (index %d)",
523 int dhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
524 uint32_t source_ip, int source_port,
525 uint32_t dest_ip, int dest_port,
526 const uint8_t *dest_arp, int ifindex, bool bcast)
528 struct sockaddr_ll dest;
529 struct ip_udp_dhcp_packet packet;
533 IP_UPD_DHCP_SIZE = sizeof(struct ip_udp_dhcp_packet) -
534 EXTEND_FOR_BUGGY_SERVERS,
535 UPD_DHCP_SIZE = IP_UPD_DHCP_SIZE -
536 offsetof(struct ip_udp_dhcp_packet, udp),
539 fd = socket(PF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
544 dhcp_pkt->flags |= htons(BROADCAST_FLAG);
546 memset(&dest, 0, sizeof(dest));
547 memset(&packet, 0, sizeof(packet));
548 packet.data = *dhcp_pkt;
550 dest.sll_family = AF_PACKET;
551 dest.sll_protocol = htons(ETH_P_IP);
552 dest.sll_ifindex = ifindex;
554 memcpy(dest.sll_addr, dest_arp, 6);
555 if (bind(fd, (struct sockaddr *)&dest, sizeof(dest)) < 0) {
561 packet.ip.protocol = IPPROTO_UDP;
562 packet.ip.saddr = source_ip;
563 packet.ip.daddr = dest_ip;
564 packet.udp.source = htons(source_port);
565 packet.udp.dest = htons(dest_port);
566 /* size, excluding IP header: */
567 packet.udp.len = htons(UPD_DHCP_SIZE);
568 /* for UDP checksumming, ip.len is set to UDP packet len */
569 packet.ip.tot_len = packet.udp.len;
570 packet.udp.check = dhcp_checksum(&packet, IP_UPD_DHCP_SIZE);
571 /* but for sending, it is set to IP packet len */
572 packet.ip.tot_len = htons(IP_UPD_DHCP_SIZE);
573 packet.ip.ihl = sizeof(packet.ip) >> 2;
574 packet.ip.version = IPVERSION;
575 packet.ip.ttl = IPDEFTTL;
576 packet.ip.check = dhcp_checksum(&packet.ip, sizeof(packet.ip));
579 * Currently we send full-sized DHCP packets (zero padded).
580 * If you need to change this: last byte of the packet is
581 * packet.data.options[dhcp_end_option(packet.data.options)]
583 n = sendto(fd, &packet, IP_UPD_DHCP_SIZE, 0,
584 (struct sockaddr *) &dest, sizeof(dest));
596 int dhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
597 uint32_t source_ip, int source_port,
598 uint32_t dest_ip, int dest_port)
600 struct sockaddr_in client;
604 DHCP_SIZE = sizeof(struct dhcp_packet) -
605 EXTEND_FOR_BUGGY_SERVERS,
608 fd = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
612 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
618 memset(&client, 0, sizeof(client));
619 client.sin_family = AF_INET;
620 client.sin_port = htons(source_port);
621 client.sin_addr.s_addr = htonl(source_ip);
622 if (bind(fd, (struct sockaddr *) &client, sizeof(client)) < 0) {
628 memset(&client, 0, sizeof(client));
629 client.sin_family = AF_INET;
630 client.sin_port = htons(dest_port);
631 client.sin_addr.s_addr = htonl(dest_ip);
632 if (connect(fd, (struct sockaddr *) &client, sizeof(client)) < 0) {
638 n = write(fd, dhcp_pkt, DHCP_SIZE);
650 int dhcp_l3_socket(int port, const char *interface, int family)
652 int fd, opt = 1, len;
653 struct sockaddr_in addr4;
654 struct sockaddr_in6 addr6;
655 struct sockaddr *addr;
657 fd = socket(family, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
661 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
667 if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
668 interface, strlen(interface) + 1) < 0) {
674 if (family == AF_INET) {
675 memset(&addr4, 0, sizeof(addr4));
676 addr4.sin_family = family;
677 addr4.sin_port = htons(port);
678 addr = (struct sockaddr *)&addr4;
680 } else if (family == AF_INET6) {
681 memset(&addr6, 0, sizeof(addr6));
682 addr6.sin6_family = family;
683 addr6.sin6_port = htons(port);
684 addr = (struct sockaddr *)&addr6;
691 if (bind(fd, addr, len) != 0) {
699 char *get_interface_name(int index)
707 sk = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
709 perror("Open socket error");
713 memset(&ifr, 0, sizeof(ifr));
714 ifr.ifr_ifindex = index;
716 err = ioctl(sk, SIOCGIFNAME, &ifr);
718 perror("Get interface name error");
725 return g_strdup(ifr.ifr_name);
728 bool interface_is_up(int index)
734 sk = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
736 perror("Open socket error");
740 memset(&ifr, 0, sizeof(ifr));
741 ifr.ifr_ifindex = index;
743 err = ioctl(sk, SIOCGIFNAME, &ifr);
745 perror("Get interface name error");
749 err = ioctl(sk, SIOCGIFFLAGS, &ifr);
751 perror("Get interface flags error");
755 if (ifr.ifr_flags & IFF_UP)