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, uint16_t packet_len, int code)
79 uint8_t *optionptr, *options_end;
83 /* option bytes: [code][len][data1][data2]..[dataLEN] */
84 optionptr = packet->options;
85 rem = sizeof(packet->options);
86 options_len = packet_len - (sizeof(*packet) - sizeof(packet->options));
87 options_end = optionptr + options_len - 1;
90 if ((rem <= 0) && (optionptr + OPT_CODE > options_end))
91 /* Bad packet, malformed option field */
94 if (optionptr[OPT_CODE] == DHCP_PADDING) {
101 if (optionptr[OPT_CODE] == DHCP_END) {
102 if (overload & FILE_FIELD) {
103 overload &= ~FILE_FIELD;
105 optionptr = packet->file;
106 rem = sizeof(packet->file);
109 } else if (overload & SNAME_FIELD) {
110 overload &= ~SNAME_FIELD;
112 optionptr = packet->sname;
113 rem = sizeof(packet->sname);
121 if (optionptr + OPT_LEN > options_end) {
122 /* bad packet, would read length field from OOB */
126 len = 2 + optionptr[OPT_LEN];
130 continue; /* complain and return NULL */
132 if (optionptr[OPT_CODE] == code) {
133 if (optionptr + len > options_end) {
134 /* bad packet, option length points OOB */
137 return optionptr + OPT_DATA;
141 if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD)
142 overload |= optionptr[OPT_DATA];
150 int dhcp_end_option(uint8_t *optionptr)
154 while (optionptr[i] != DHCP_END) {
155 if (optionptr[i] != DHCP_PADDING)
156 i += optionptr[i + OPT_LEN] + OPT_DATA - 1;
164 uint8_t *dhcpv6_get_option(struct dhcpv6_packet *packet, uint16_t pkt_len,
165 int code, uint16_t *option_len, int *option_count)
168 uint8_t *optionptr, *found = NULL;
169 uint16_t opt_code, opt_len, len;
171 optionptr = packet->options;
172 rem = pkt_len - 1 - 3;
178 opt_code = optionptr[0] << 8 | optionptr[1];
179 opt_len = len = optionptr[2] << 8 | optionptr[3];
180 len += 2 + 2; /* skip code and len */
189 if (opt_code == code) {
191 *option_len = opt_len;
192 found = optionptr + 2 + 2;
203 *option_count = count;
215 uint8_t *dhcpv6_get_sub_option(unsigned char *option, uint16_t max_len,
216 uint16_t *option_code, uint16_t *option_len)
221 rem = max_len - 2 - 2;
227 code = option[0] << 8 | option[1];
228 len = option[2] << 8 | option[3];
241 * Add an option (supplied in binary form) to the options.
242 * Option format: [code][len][data1][data2]..[dataLEN]
244 void dhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
247 uint8_t *optionptr = packet->options;
248 unsigned end = dhcp_end_option(optionptr);
250 len = OPT_DATA + addopt[OPT_LEN];
252 /* end position + (option code/length + addopt length) + end option */
253 if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE)
254 /* option did not fit into the packet */
257 memcpy(optionptr + end, addopt, len);
259 optionptr[end + len] = DHCP_END;
263 * Add an option (supplied in binary form) to the options.
264 * Option format: [code][len][data1][data2]..[dataLEN]
266 void dhcpv6_add_binary_option(struct dhcpv6_packet *packet, uint16_t max_len,
267 uint16_t *pkt_len, uint8_t *addopt)
270 uint8_t *optionptr = packet->options;
272 len = 2 + 2 + (addopt[2] << 8 | addopt[3]);
274 /* end position + (option code/length + addopt length) */
275 if (*pkt_len + len >= max_len)
276 /* option did not fit into the packet */
279 memcpy(optionptr + *pkt_len, addopt, len);
283 static GDHCPOptionType check_option(uint8_t code, uint8_t data_len)
285 GDHCPOptionType type = dhcp_get_code_type(code);
288 if (type == OPTION_UNKNOWN)
291 len = dhcp_option_lengths[type & OPTION_TYPE_MASK];
292 if (len != data_len) {
293 printf("Invalid option len %d (expecting %d) for code 0x%x\n",
294 data_len, len, code);
295 return OPTION_UNKNOWN;
301 void dhcp_add_option_uint32(struct dhcp_packet *packet, uint8_t code,
306 if (check_option(code, sizeof(data)) == OPTION_UNKNOWN)
309 option[OPT_CODE] = code;
310 option[OPT_LEN] = sizeof(data);
311 put_be32(data, option + OPT_DATA);
313 dhcp_add_binary_option(packet, option);
316 void dhcp_add_option_uint16(struct dhcp_packet *packet, uint8_t code,
321 if (check_option(code, sizeof(data)) == OPTION_UNKNOWN)
324 option[OPT_CODE] = code;
325 option[OPT_LEN] = sizeof(data);
326 put_be16(data, option + OPT_DATA);
328 dhcp_add_binary_option(packet, option);
331 void dhcp_add_option_uint8(struct dhcp_packet *packet, uint8_t code,
336 if (check_option(code, sizeof(data)) == OPTION_UNKNOWN)
339 option[OPT_CODE] = code;
340 option[OPT_LEN] = sizeof(data);
341 option[OPT_DATA] = data;
343 dhcp_add_binary_option(packet, option);
346 void dhcp_init_header(struct dhcp_packet *packet, char type)
348 memset(packet, 0, sizeof(*packet));
350 packet->op = BOOTREQUEST;
356 packet->op = BOOTREPLY;
361 packet->cookie = htonl(DHCP_MAGIC);
362 packet->options[0] = DHCP_END;
364 dhcp_add_option_uint8(packet, DHCP_MESSAGE_TYPE, type);
367 void dhcpv6_init_header(struct dhcpv6_packet *packet, uint8_t type)
372 memset(packet, 0, sizeof(*packet));
374 packet->message = type;
376 __connman_util_get_random(&rand);
379 packet->transaction_id[0] = (id >> 16) & 0xff;
380 packet->transaction_id[1] = (id >> 8) & 0xff;
381 packet->transaction_id[2] = id & 0xff;
384 int dhcp_recv_l3_packet(struct dhcp_packet *packet, int fd)
388 memset(packet, 0, sizeof(*packet));
390 n = read(fd, packet, sizeof(*packet));
394 if (packet->cookie != htonl(DHCP_MAGIC))
400 int dhcpv6_recv_l3_packet(struct dhcpv6_packet **packet, unsigned char *buf,
405 n = read(fd, buf, buf_len);
409 *packet = (struct dhcpv6_packet *)buf;
414 /* TODO: Use glib checksum */
415 uint16_t dhcp_checksum(void *addr, int count)
418 * Compute Internet Checksum for "count" bytes
419 * beginning at location "addr".
422 uint16_t *source = (uint16_t *) addr;
425 /* This is the inner loop */
430 /* Add left-over byte, if any */
432 /* Make sure that the left-over byte is added correctly both
433 * with little and big endian hosts */
435 *(uint8_t *) &tmp = *(uint8_t *) source;
438 /* Fold 32-bit sum to 16 bits */
440 sum = (sum & 0xffff) + (sum >> 16);
445 #define IN6ADDR_ALL_DHCP_RELAY_AGENTS_AND_SERVERS_MC_INIT \
446 { { { 0xff,0x02,0,0,0,0,0,0,0,0,0,0,0,0x1,0,0x2 } } } /* ff02::1:2 */
447 static const struct in6_addr in6addr_all_dhcp_relay_agents_and_servers_mc =
448 IN6ADDR_ALL_DHCP_RELAY_AGENTS_AND_SERVERS_MC_INIT;
450 int dhcpv6_send_packet(int index, struct dhcpv6_packet *dhcp_pkt, int len)
454 struct in6_pktinfo *pktinfo;
455 struct cmsghdr *cmsg;
456 int fd, ret, opt = 1;
457 struct sockaddr_in6 src;
458 struct sockaddr_in6 dst;
460 size_t control_buf_len;
462 fd = socket(PF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
466 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
472 memset(&src, 0, sizeof(src));
473 src.sin6_family = AF_INET6;
474 src.sin6_port = htons(DHCPV6_CLIENT_PORT);
476 if (bind(fd, (struct sockaddr *) &src, sizeof(src)) <0) {
482 memset(&dst, 0, sizeof(dst));
483 dst.sin6_family = AF_INET6;
484 dst.sin6_port = htons(DHCPV6_SERVER_PORT);
486 dst.sin6_addr = in6addr_all_dhcp_relay_agents_and_servers_mc;
488 control_buf_len = CMSG_SPACE(sizeof(struct in6_pktinfo));
489 control_buf = g_try_malloc0(control_buf_len);
495 memset(&m, 0, sizeof(m));
496 memset(&v, 0, sizeof(v));
499 m.msg_namelen = sizeof(dst);
501 v.iov_base = (char *)dhcp_pkt;
506 m.msg_control = control_buf;
507 m.msg_controllen = control_buf_len;
508 cmsg = CMSG_FIRSTHDR(&m);
509 cmsg->cmsg_level = IPPROTO_IPV6;
510 cmsg->cmsg_type = IPV6_PKTINFO;
511 cmsg->cmsg_len = CMSG_LEN(sizeof(*pktinfo));
513 pktinfo = (struct in6_pktinfo *)CMSG_DATA(cmsg);
514 memset(pktinfo, 0, sizeof(*pktinfo));
515 pktinfo->ipi6_ifindex = index;
516 m.msg_controllen = cmsg->cmsg_len;
518 ret = sendmsg(fd, &m, 0);
520 char *msg = "DHCPv6 msg send failed";
522 if (errno == EADDRNOTAVAIL) {
523 char *str = g_strdup_printf("%s (index %d)",
537 int dhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
538 uint32_t source_ip, int source_port,
539 uint32_t dest_ip, int dest_port,
540 const uint8_t *dest_arp, int ifindex, bool bcast)
542 struct sockaddr_ll dest;
543 struct ip_udp_dhcp_packet packet;
547 IP_UPD_DHCP_SIZE = sizeof(struct ip_udp_dhcp_packet) -
548 EXTEND_FOR_BUGGY_SERVERS,
549 UPD_DHCP_SIZE = IP_UPD_DHCP_SIZE -
550 offsetof(struct ip_udp_dhcp_packet, udp),
553 fd = socket(PF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
558 dhcp_pkt->flags |= htons(BROADCAST_FLAG);
560 memset(&dest, 0, sizeof(dest));
561 memset(&packet, 0, sizeof(packet));
562 packet.data = *dhcp_pkt;
564 dest.sll_family = AF_PACKET;
565 dest.sll_protocol = htons(ETH_P_IP);
566 dest.sll_ifindex = ifindex;
568 memcpy(dest.sll_addr, dest_arp, 6);
569 if (bind(fd, (struct sockaddr *)&dest, sizeof(dest)) < 0) {
575 packet.ip.protocol = IPPROTO_UDP;
576 packet.ip.saddr = source_ip;
577 packet.ip.daddr = dest_ip;
578 packet.udp.source = htons(source_port);
579 packet.udp.dest = htons(dest_port);
580 /* size, excluding IP header: */
581 packet.udp.len = htons(UPD_DHCP_SIZE);
582 /* for UDP checksumming, ip.len is set to UDP packet len */
583 packet.ip.tot_len = packet.udp.len;
584 packet.udp.check = dhcp_checksum(&packet, IP_UPD_DHCP_SIZE);
585 /* but for sending, it is set to IP packet len */
586 packet.ip.tot_len = htons(IP_UPD_DHCP_SIZE);
587 packet.ip.ihl = sizeof(packet.ip) >> 2;
588 packet.ip.version = IPVERSION;
589 packet.ip.ttl = IPDEFTTL;
590 packet.ip.check = dhcp_checksum(&packet.ip, sizeof(packet.ip));
593 * Currently we send full-sized DHCP packets (zero padded).
594 * If you need to change this: last byte of the packet is
595 * packet.data.options[dhcp_end_option(packet.data.options)]
597 n = sendto(fd, &packet, IP_UPD_DHCP_SIZE, 0,
598 (struct sockaddr *) &dest, sizeof(dest));
610 int dhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
611 uint32_t source_ip, int source_port,
612 uint32_t dest_ip, int dest_port,
613 const char *interface)
615 struct sockaddr_in client;
619 DHCP_SIZE = sizeof(struct dhcp_packet) -
620 EXTEND_FOR_BUGGY_SERVERS,
623 fd = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
627 if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
628 interface, strlen(interface) + 1) < 0) {
634 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
640 memset(&client, 0, sizeof(client));
641 client.sin_family = AF_INET;
642 client.sin_port = htons(source_port);
643 client.sin_addr.s_addr = htonl(source_ip);
644 if (bind(fd, (struct sockaddr *) &client, sizeof(client)) < 0) {
650 memset(&client, 0, sizeof(client));
651 client.sin_family = AF_INET;
652 client.sin_port = htons(dest_port);
653 client.sin_addr.s_addr = htonl(dest_ip);
654 if (connect(fd, (struct sockaddr *) &client, sizeof(client)) < 0) {
660 n = write(fd, dhcp_pkt, DHCP_SIZE);
672 int dhcp_l3_socket(int port, const char *interface, int family)
674 int fd, opt = 1, len;
675 struct sockaddr_in addr4;
676 struct sockaddr_in6 addr6;
677 struct sockaddr *addr;
679 fd = socket(family, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
683 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
689 if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
690 interface, strlen(interface) + 1) < 0) {
696 if (family == AF_INET) {
697 memset(&addr4, 0, sizeof(addr4));
698 addr4.sin_family = family;
699 addr4.sin_port = htons(port);
700 addr = (struct sockaddr *)&addr4;
702 } else if (family == AF_INET6) {
703 memset(&addr6, 0, sizeof(addr6));
704 addr6.sin6_family = family;
705 addr6.sin6_port = htons(port);
706 addr = (struct sockaddr *)&addr6;
713 if (bind(fd, addr, len) != 0) {
721 char *get_interface_name(int index)
729 sk = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
731 perror("Open socket error");
735 memset(&ifr, 0, sizeof(ifr));
736 ifr.ifr_ifindex = index;
738 err = ioctl(sk, SIOCGIFNAME, &ifr);
740 perror("Get interface name error");
747 return g_strdup(ifr.ifr_name);
750 bool interface_is_up(int index)
756 sk = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
758 perror("Open socket error");
762 memset(&ifr, 0, sizeof(ifr));
763 ifr.ifr_ifindex = index;
765 err = ioctl(sk, SIOCGIFNAME, &ifr);
767 perror("Get interface name error");
771 err = ioctl(sk, SIOCGIFFLAGS, &ifr);
773 perror("Get interface flags error");
777 if (ifr.ifr_flags & IFF_UP)