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 */
53 { OPTION_STRING, 0x2b }, /* vendor specific element information */
55 { OPTION_U32, 0x33 }, /* dhcp-lease-time */
56 /* Options below will not be exposed to user */
57 { OPTION_IP, 0x32 }, /* requested-ip */
58 { OPTION_U8, 0x35 }, /* message-type */
59 { OPTION_U32, 0x36 }, /* server-id */
60 { OPTION_U16, 0x39 }, /* max-size */
61 { OPTION_STRING, 0x3c }, /* vendor */
62 { OPTION_STRING, 0x3d }, /* client-id */
63 { OPTION_STRING, 0xfc }, /* UNOFFICIAL proxy-pac */
64 { OPTION_UNKNOWN, 0x00 },
67 GDHCPOptionType dhcp_get_code_type(uint8_t code)
71 for (i = 0; client_options[i].code; i++) {
72 if (client_options[i].code == code)
73 return client_options[i].type;
76 return OPTION_UNKNOWN;
79 uint8_t *dhcp_get_option(struct dhcp_packet *packet, uint16_t packet_len, int code)
82 uint8_t *optionptr, *options_end;
86 /* option bytes: [code][len][data1][data2]..[dataLEN] */
87 optionptr = packet->options;
88 rem = sizeof(packet->options);
89 options_len = packet_len - (sizeof(*packet) - sizeof(packet->options));
90 options_end = optionptr + options_len - 1;
93 if ((rem <= 0) && (optionptr + OPT_CODE > options_end))
94 /* Bad packet, malformed option field */
97 if (optionptr[OPT_CODE] == DHCP_PADDING) {
104 if (optionptr[OPT_CODE] == DHCP_END) {
105 if (overload & FILE_FIELD) {
106 overload &= ~FILE_FIELD;
108 optionptr = packet->file;
109 rem = sizeof(packet->file);
112 } else if (overload & SNAME_FIELD) {
113 overload &= ~SNAME_FIELD;
115 optionptr = packet->sname;
116 rem = sizeof(packet->sname);
124 if (optionptr + OPT_LEN > options_end) {
125 /* bad packet, would read length field from OOB */
129 len = 2 + optionptr[OPT_LEN];
133 continue; /* complain and return NULL */
135 if (optionptr[OPT_CODE] == code) {
136 if (optionptr + len > options_end) {
137 /* bad packet, option length points OOB */
140 return optionptr + OPT_DATA;
144 if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD)
145 overload |= optionptr[OPT_DATA];
153 int dhcp_end_option(uint8_t *optionptr)
157 while (optionptr[i] != DHCP_END) {
158 if (optionptr[i] != DHCP_PADDING)
159 i += optionptr[i + OPT_LEN] + OPT_DATA - 1;
167 uint8_t *dhcpv6_get_option(struct dhcpv6_packet *packet, uint16_t pkt_len,
168 int code, uint16_t *option_len, int *option_count)
171 uint8_t *optionptr, *found = NULL;
172 uint16_t opt_code, opt_len, len;
174 optionptr = packet->options;
175 rem = pkt_len - 1 - 3;
181 opt_code = optionptr[0] << 8 | optionptr[1];
182 opt_len = len = optionptr[2] << 8 | optionptr[3];
183 len += 2 + 2; /* skip code and len */
192 if (opt_code == code) {
194 *option_len = opt_len;
195 found = optionptr + 2 + 2;
206 *option_count = count;
218 uint8_t *dhcpv6_get_sub_option(unsigned char *option, uint16_t max_len,
219 uint16_t *option_code, uint16_t *option_len)
224 rem = max_len - 2 - 2;
230 code = option[0] << 8 | option[1];
231 len = option[2] << 8 | option[3];
244 * Add an option (supplied in binary form) to the options.
245 * Option format: [code][len][data1][data2]..[dataLEN]
247 void dhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
250 uint8_t *optionptr = packet->options;
251 unsigned end = dhcp_end_option(optionptr);
253 len = OPT_DATA + addopt[OPT_LEN];
255 /* end position + (option code/length + addopt length) + end option */
256 if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE)
257 /* option did not fit into the packet */
260 memcpy(optionptr + end, addopt, len);
262 optionptr[end + len] = DHCP_END;
266 * Add an option (supplied in binary form) to the options.
267 * Option format: [code][len][data1][data2]..[dataLEN]
269 void dhcpv6_add_binary_option(struct dhcpv6_packet *packet, uint16_t max_len,
270 uint16_t *pkt_len, uint8_t *addopt)
273 uint8_t *optionptr = packet->options;
275 len = 2 + 2 + (addopt[2] << 8 | addopt[3]);
277 /* end position + (option code/length + addopt length) */
278 if (*pkt_len + len >= max_len)
279 /* option did not fit into the packet */
282 memcpy(optionptr + *pkt_len, addopt, len);
286 static GDHCPOptionType check_option(uint8_t code, uint8_t data_len)
288 GDHCPOptionType type = dhcp_get_code_type(code);
291 if (type == OPTION_UNKNOWN)
294 len = dhcp_option_lengths[type & OPTION_TYPE_MASK];
295 if (len != data_len) {
296 printf("Invalid option len %d (expecting %d) for code 0x%x\n",
297 data_len, len, code);
298 return OPTION_UNKNOWN;
304 void dhcp_add_option_uint32(struct dhcp_packet *packet, uint8_t code,
309 if (check_option(code, sizeof(data)) == OPTION_UNKNOWN)
312 option[OPT_CODE] = code;
313 option[OPT_LEN] = sizeof(data);
314 put_be32(data, option + OPT_DATA);
316 dhcp_add_binary_option(packet, option);
319 void dhcp_add_option_uint16(struct dhcp_packet *packet, uint8_t code,
324 if (check_option(code, sizeof(data)) == OPTION_UNKNOWN)
327 option[OPT_CODE] = code;
328 option[OPT_LEN] = sizeof(data);
329 put_be16(data, option + OPT_DATA);
331 dhcp_add_binary_option(packet, option);
334 void dhcp_add_option_uint8(struct dhcp_packet *packet, uint8_t code,
339 if (check_option(code, sizeof(data)) == OPTION_UNKNOWN)
342 option[OPT_CODE] = code;
343 option[OPT_LEN] = sizeof(data);
344 option[OPT_DATA] = data;
346 dhcp_add_binary_option(packet, option);
349 void dhcp_init_header(struct dhcp_packet *packet, char type)
351 memset(packet, 0, sizeof(*packet));
353 packet->op = BOOTREQUEST;
359 packet->op = BOOTREPLY;
364 packet->cookie = htonl(DHCP_MAGIC);
365 packet->options[0] = DHCP_END;
367 dhcp_add_option_uint8(packet, DHCP_MESSAGE_TYPE, type);
370 void dhcpv6_init_header(struct dhcpv6_packet *packet, uint8_t type)
375 memset(packet, 0, sizeof(*packet));
377 packet->message = type;
379 __connman_util_get_random(&rand);
382 packet->transaction_id[0] = (id >> 16) & 0xff;
383 packet->transaction_id[1] = (id >> 8) & 0xff;
384 packet->transaction_id[2] = id & 0xff;
387 int dhcp_recv_l3_packet(struct dhcp_packet *packet, int fd)
391 memset(packet, 0, sizeof(*packet));
393 n = read(fd, packet, sizeof(*packet));
397 if (packet->cookie != htonl(DHCP_MAGIC))
403 int dhcpv6_recv_l3_packet(struct dhcpv6_packet **packet, unsigned char *buf,
408 n = read(fd, buf, buf_len);
412 *packet = (struct dhcpv6_packet *)buf;
417 /* TODO: Use glib checksum */
418 uint16_t dhcp_checksum(void *addr, int count)
421 * Compute Internet Checksum for "count" bytes
422 * beginning at location "addr".
425 uint16_t *source = (uint16_t *) addr;
428 /* This is the inner loop */
433 /* Add left-over byte, if any */
435 /* Make sure that the left-over byte is added correctly both
436 * with little and big endian hosts */
438 *(uint8_t *) &tmp = *(uint8_t *) source;
441 /* Fold 32-bit sum to 16 bits */
443 sum = (sum & 0xffff) + (sum >> 16);
448 #define IN6ADDR_ALL_DHCP_RELAY_AGENTS_AND_SERVERS_MC_INIT \
449 { { { 0xff,0x02,0,0,0,0,0,0,0,0,0,0,0,0x1,0,0x2 } } } /* ff02::1:2 */
450 static const struct in6_addr in6addr_all_dhcp_relay_agents_and_servers_mc =
451 IN6ADDR_ALL_DHCP_RELAY_AGENTS_AND_SERVERS_MC_INIT;
453 int dhcpv6_send_packet(int index, struct dhcpv6_packet *dhcp_pkt, int len)
457 struct in6_pktinfo *pktinfo;
458 struct cmsghdr *cmsg;
459 int fd, ret, opt = 1;
460 struct sockaddr_in6 src;
461 struct sockaddr_in6 dst;
463 size_t control_buf_len;
465 fd = socket(PF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
469 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
475 memset(&src, 0, sizeof(src));
476 src.sin6_family = AF_INET6;
477 src.sin6_port = htons(DHCPV6_CLIENT_PORT);
479 if (bind(fd, (struct sockaddr *) &src, sizeof(src)) <0) {
485 memset(&dst, 0, sizeof(dst));
486 dst.sin6_family = AF_INET6;
487 dst.sin6_port = htons(DHCPV6_SERVER_PORT);
489 dst.sin6_addr = in6addr_all_dhcp_relay_agents_and_servers_mc;
491 control_buf_len = CMSG_SPACE(sizeof(struct in6_pktinfo));
492 control_buf = g_try_malloc0(control_buf_len);
498 memset(&m, 0, sizeof(m));
499 memset(&v, 0, sizeof(v));
502 m.msg_namelen = sizeof(dst);
504 v.iov_base = (char *)dhcp_pkt;
509 m.msg_control = control_buf;
510 m.msg_controllen = control_buf_len;
511 cmsg = CMSG_FIRSTHDR(&m);
512 cmsg->cmsg_level = IPPROTO_IPV6;
513 cmsg->cmsg_type = IPV6_PKTINFO;
514 cmsg->cmsg_len = CMSG_LEN(sizeof(*pktinfo));
516 pktinfo = (struct in6_pktinfo *)CMSG_DATA(cmsg);
517 memset(pktinfo, 0, sizeof(*pktinfo));
518 pktinfo->ipi6_ifindex = index;
519 m.msg_controllen = cmsg->cmsg_len;
521 ret = sendmsg(fd, &m, 0);
523 char *msg = "DHCPv6 msg send failed";
525 if (errno == EADDRNOTAVAIL) {
526 char *str = g_strdup_printf("%s (index %d)",
540 int dhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
541 uint32_t source_ip, int source_port,
542 uint32_t dest_ip, int dest_port,
543 const uint8_t *dest_arp, int ifindex, bool bcast)
545 struct sockaddr_ll dest;
546 struct ip_udp_dhcp_packet packet;
550 IP_UPD_DHCP_SIZE = sizeof(struct ip_udp_dhcp_packet) -
551 EXTEND_FOR_BUGGY_SERVERS,
552 UPD_DHCP_SIZE = IP_UPD_DHCP_SIZE -
553 offsetof(struct ip_udp_dhcp_packet, udp),
556 fd = socket(PF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
561 dhcp_pkt->flags |= htons(BROADCAST_FLAG);
563 memset(&dest, 0, sizeof(dest));
564 memset(&packet, 0, sizeof(packet));
565 packet.data = *dhcp_pkt;
567 dest.sll_family = AF_PACKET;
568 dest.sll_protocol = htons(ETH_P_IP);
569 dest.sll_ifindex = ifindex;
571 memcpy(dest.sll_addr, dest_arp, 6);
572 if (bind(fd, (struct sockaddr *)&dest, sizeof(dest)) < 0) {
578 packet.ip.protocol = IPPROTO_UDP;
579 packet.ip.saddr = source_ip;
580 packet.ip.daddr = dest_ip;
581 packet.udp.source = htons(source_port);
582 packet.udp.dest = htons(dest_port);
583 /* size, excluding IP header: */
584 packet.udp.len = htons(UPD_DHCP_SIZE);
585 /* for UDP checksumming, ip.len is set to UDP packet len */
586 packet.ip.tot_len = packet.udp.len;
587 packet.udp.check = dhcp_checksum(&packet, IP_UPD_DHCP_SIZE);
588 /* but for sending, it is set to IP packet len */
589 packet.ip.tot_len = htons(IP_UPD_DHCP_SIZE);
590 packet.ip.ihl = sizeof(packet.ip) >> 2;
591 packet.ip.version = IPVERSION;
592 packet.ip.ttl = IPDEFTTL;
593 packet.ip.check = dhcp_checksum(&packet.ip, sizeof(packet.ip));
596 * Currently we send full-sized DHCP packets (zero padded).
597 * If you need to change this: last byte of the packet is
598 * packet.data.options[dhcp_end_option(packet.data.options)]
600 n = sendto(fd, &packet, IP_UPD_DHCP_SIZE, 0,
601 (struct sockaddr *) &dest, sizeof(dest));
613 int dhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
614 uint32_t source_ip, int source_port,
615 uint32_t dest_ip, int dest_port,
616 const char *interface)
618 struct sockaddr_in client;
622 DHCP_SIZE = sizeof(struct dhcp_packet) -
623 EXTEND_FOR_BUGGY_SERVERS,
626 fd = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
630 if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
631 interface, strlen(interface) + 1) < 0) {
637 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
643 memset(&client, 0, sizeof(client));
644 client.sin_family = AF_INET;
645 client.sin_port = htons(source_port);
646 client.sin_addr.s_addr = htonl(source_ip);
647 if (bind(fd, (struct sockaddr *) &client, sizeof(client)) < 0) {
653 memset(&client, 0, sizeof(client));
654 client.sin_family = AF_INET;
655 client.sin_port = htons(dest_port);
656 client.sin_addr.s_addr = htonl(dest_ip);
657 if (connect(fd, (struct sockaddr *) &client, sizeof(client)) < 0) {
663 n = write(fd, dhcp_pkt, DHCP_SIZE);
675 int dhcp_l3_socket(int port, const char *interface, int family)
677 int fd, opt = 1, len;
678 struct sockaddr_in addr4;
679 struct sockaddr_in6 addr6;
680 struct sockaddr *addr;
682 fd = socket(family, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
686 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
692 if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
693 interface, strlen(interface) + 1) < 0) {
699 if (family == AF_INET) {
700 memset(&addr4, 0, sizeof(addr4));
701 addr4.sin_family = family;
702 addr4.sin_port = htons(port);
703 addr = (struct sockaddr *)&addr4;
705 } else if (family == AF_INET6) {
706 memset(&addr6, 0, sizeof(addr6));
707 addr6.sin6_family = family;
708 addr6.sin6_port = htons(port);
709 addr = (struct sockaddr *)&addr6;
716 if (bind(fd, addr, len) != 0) {
724 char *get_interface_name(int index)
732 sk = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
734 perror("Open socket error");
738 memset(&ifr, 0, sizeof(ifr));
739 ifr.ifr_ifindex = index;
741 err = ioctl(sk, SIOCGIFNAME, &ifr);
743 perror("Get interface name error");
750 return g_strdup(ifr.ifr_name);
753 bool interface_is_up(int index)
759 sk = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
761 perror("Open socket error");
765 memset(&ifr, 0, sizeof(ifr));
766 ifr.ifr_ifindex = index;
768 err = ioctl(sk, SIOCGIFNAME, &ifr);
770 perror("Get interface name error");
774 err = ioctl(sk, SIOCGIFFLAGS, &ifr);
776 perror("Get interface flags error");
780 if (ifr.ifr_flags & IFF_UP)