| /* |
| * dhcpcd - DHCP client daemon |
| * Copyright (c) 2006-2009 Roy Marples <roy@marples.name> |
| * All rights reserved |
| |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #include <ctype.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stddef.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <syslog.h> |
| #include <unistd.h> |
| |
| #include "config.h" |
| #include "common.h" |
| #include "dhcp.h" |
| #include "if-options.h" |
| |
| #define REQUEST (1 << 0) |
| #define UINT8 (1 << 1) |
| #define UINT16 (1 << 2) |
| #define SINT16 (1 << 3) |
| #define UINT32 (1 << 4) |
| #define SINT32 (1 << 5) |
| #define IPV4 (1 << 6) |
| #define STRING (1 << 7) |
| #define PAIR (1 << 8) |
| #define ARRAY (1 << 9) |
| #define RFC3361 (1 << 10) |
| #define RFC3397 (1 << 11) |
| #define RFC3442 (1 << 12) |
| |
| #define IPV4R IPV4 | REQUEST |
| |
| #define DAD "Duplicate address detected" |
| |
| /* Our aggregate option buffer. |
| * We ONLY use this when options are split, which for most purposes is |
| * practically never. See RFC3396 for details. */ |
| static uint8_t *opt_buffer; |
| |
| struct dhcp_opt { |
| uint8_t option; |
| int type; |
| const char *var; |
| }; |
| |
| static const struct dhcp_opt dhcp_opts[] = { |
| { 1, IPV4 | REQUEST, "subnet_mask" }, |
| /* RFC 3442 states that the CSR has to come before all other |
| * routes. For completeness, we also specify static routes, |
| * then routers. */ |
| { 121, RFC3442, "classless_static_routes" }, |
| { 249, RFC3442, "ms_classless_static_routes" }, |
| { 33, IPV4 | ARRAY | REQUEST, "static_routes" }, |
| { 3, IPV4 | ARRAY | REQUEST, "routers" }, |
| { 2, UINT32, "time_offset" }, |
| { 4, IPV4 | ARRAY, "time_servers" }, |
| { 5, IPV4 | ARRAY, "ien116_name_servers" }, |
| { 6, IPV4 | ARRAY, "domain_name_servers" }, |
| { 7, IPV4 | ARRAY, "log_servers" }, |
| { 8, IPV4 | ARRAY, "cookie_servers" }, |
| { 9, IPV4 | ARRAY, "lpr_servers" }, |
| { 10, IPV4 | ARRAY, "impress_servers" }, |
| { 11, IPV4 | ARRAY, "resource_location_servers" }, |
| { 12, STRING, "host_name" }, |
| { 13, UINT16, "boot_size" }, |
| { 14, STRING, "merit_dump" }, |
| { 15, STRING, "domain_name" }, |
| { 16, IPV4, "swap_server" }, |
| { 17, STRING, "root_path" }, |
| { 18, STRING, "extensions_path" }, |
| { 19, UINT8, "ip_forwarding" }, |
| { 20, UINT8, "non_local_source_routing" }, |
| { 21, IPV4 | ARRAY, "policy_filter" }, |
| { 22, SINT16, "max_dgram_reassembly" }, |
| { 23, UINT16, "default_ip_ttl" }, |
| { 24, UINT32, "path_mtu_aging_timeout" }, |
| { 25, UINT16 | ARRAY, "path_mtu_plateau_table" }, |
| { 26, UINT16, "interface_mtu" }, |
| { 27, UINT8, "all_subnets_local" }, |
| { 28, IPV4 | REQUEST, "broadcast_address" }, |
| { 29, UINT8, "perform_mask_discovery" }, |
| { 30, UINT8, "mask_supplier" }, |
| { 31, UINT8, "router_discovery" }, |
| { 32, IPV4, "router_solicitation_address" }, |
| { 34, UINT8, "trailer_encapsulation" }, |
| { 35, UINT32, "arp_cache_timeout" }, |
| { 36, UINT16, "ieee802_3_encapsulation" }, |
| { 37, UINT8, "default_tcp_ttl" }, |
| { 38, UINT32, "tcp_keepalive_interval" }, |
| { 39, UINT8, "tcp_keepalive_garbage" }, |
| { 40, STRING, "nis_domain" }, |
| { 41, IPV4 | ARRAY, "nis_servers" }, |
| { 42, IPV4 | ARRAY, "ntp_servers" }, |
| { 43, STRING, "vendor_encapsulated_options" }, |
| { 44, IPV4 | ARRAY, "netbios_name_servers" }, |
| { 45, IPV4, "netbios_dd_server" }, |
| { 46, UINT8, "netbios_node_type" }, |
| { 47, STRING, "netbios_scope" }, |
| { 48, IPV4 | ARRAY, "font_servers" }, |
| { 49, IPV4 | ARRAY, "x_display_manager" }, |
| { 50, IPV4, "dhcp_requested_address" }, |
| { 51, UINT32 | REQUEST, "dhcp_lease_time" }, |
| { 52, UINT8, "dhcp_option_overload" }, |
| { 53, UINT8, "dhcp_message_type" }, |
| { 54, IPV4, "dhcp_server_identifier" }, |
| { 55, UINT8 | ARRAY, "dhcp_parameter_request_list" }, |
| { 56, STRING, "dhcp_message" }, |
| { 57, UINT16, "dhcp_max_message_size" }, |
| { 58, UINT32 | REQUEST, "dhcp_renewal_time" }, |
| { 59, UINT32 | REQUEST, "dhcp_rebinding_time" }, |
| { 64, STRING, "nisplus_domain" }, |
| { 65, IPV4 | ARRAY, "nisplus_servers" }, |
| { 66, STRING, "tftp_server_name" }, |
| { 67, STRING, "bootfile_name" }, |
| { 68, IPV4 | ARRAY, "mobile_ip_home_agent" }, |
| { 69, IPV4 | ARRAY, "smtp_server" }, |
| { 70, IPV4 | ARRAY, "pop_server" }, |
| { 71, IPV4 | ARRAY, "nntp_server" }, |
| { 72, IPV4 | ARRAY, "www_server" }, |
| { 73, IPV4 | ARRAY, "finger_server" }, |
| { 74, IPV4 | ARRAY, "irc_server" }, |
| { 75, IPV4 | ARRAY, "streettalk_server" }, |
| { 76, IPV4 | ARRAY, "streettalk_directory_assistance_server" }, |
| { 77, STRING, "user_class" }, |
| { 81, STRING | RFC3397, "fqdn_name" }, |
| { 85, IPV4 | ARRAY, "nds_servers" }, |
| { 86, STRING, "nds_tree_name" }, |
| { 87, STRING, "nds_context" }, |
| { 88, STRING | RFC3397, "bcms_controller_names" }, |
| { 89, IPV4 | ARRAY, "bcms_controller_address" }, |
| { 91, UINT32, "client_last_transaction_time" }, |
| { 92, IPV4 | ARRAY, "associated_ip" }, |
| { 98, STRING, "uap_servers" }, |
| { 112, IPV4 | ARRAY, "netinfo_server_address" }, |
| { 113, STRING, "netinfo_server_tag" }, |
| { 114, STRING, "default_url" }, |
| { 118, IPV4, "subnet_selection" }, |
| { 119, STRING | RFC3397, "domain_search" }, |
| { 252, STRING, "wpad_url" }, |
| { 0, 0, NULL } |
| }; |
| |
| static const char *if_params[] = { |
| "interface", |
| "reason", |
| "pid", |
| "ifmetric", |
| "ifwireless", |
| "ifflags", |
| "profile", |
| "interface_order", |
| NULL |
| }; |
| |
| static const char *dhcp_params[] = { |
| "ip_address", |
| "subnet_cidr", |
| "network_number", |
| "ssid", |
| "filename", |
| "server_name", |
| NULL |
| }; |
| |
| void |
| print_options(void) |
| { |
| const struct dhcp_opt *opt; |
| const char **p; |
| |
| for (p = if_params; *p; p++) |
| printf(" - %s\n", *p); |
| |
| for (p = dhcp_params; *p; p++) |
| printf(" %s\n", *p); |
| |
| for (opt = dhcp_opts; opt->option; opt++) |
| if (opt->var) |
| printf("%03d %s\n", opt->option, opt->var); |
| } |
| |
| int make_option_mask(uint8_t *mask, const char *opts, int add) |
| { |
| char *token, *o, *p, *t; |
| const struct dhcp_opt *opt; |
| int match, n; |
| |
| o = p = xstrdup(opts); |
| while ((token = strsep(&p, ", "))) { |
| if (*token == '\0') |
| continue; |
| for (opt = dhcp_opts; opt->option; opt++) { |
| if (!opt->var) |
| continue; |
| match = 0; |
| if (strcmp(opt->var, token) == 0) |
| match = 1; |
| else { |
| errno = 0; |
| n = strtol(token, &t, 0); |
| if (errno == 0 && !*t) |
| if (opt->option == n) |
| match = 1; |
| } |
| if (match) { |
| if (add == 2 && !(opt->type & IPV4)) { |
| free(o); |
| errno = EINVAL; |
| return -1; |
| } |
| if (add == 1 || add == 2) |
| add_option_mask(mask, |
| opt->option); |
| else |
| del_option_mask(mask, |
| opt->option); |
| break; |
| } |
| } |
| if (!opt->option) { |
| free(o); |
| errno = ENOENT; |
| return -1; |
| } |
| } |
| free(o); |
| return 0; |
| } |
| |
| static int |
| valid_length(uint8_t option, int dl, int *type) |
| { |
| const struct dhcp_opt *opt; |
| ssize_t sz; |
| |
| if (dl == 0) |
| return -1; |
| |
| for (opt = dhcp_opts; opt->option; opt++) { |
| if (opt->option != option) |
| continue; |
| |
| if (type) |
| *type = opt->type; |
| |
| if (opt->type == 0 || |
| opt->type & STRING || |
| opt->type & RFC3442) |
| return 0; |
| |
| sz = 0; |
| if (opt->type & UINT32 || opt->type & IPV4) |
| sz = sizeof(uint32_t); |
| if (opt->type & UINT16) |
| sz = sizeof(uint16_t); |
| if (opt->type & UINT8) |
| sz = sizeof(uint8_t); |
| if (opt->type & IPV4 || opt->type & ARRAY) |
| return dl % sz; |
| return (dl == sz ? 0 : -1); |
| } |
| |
| /* unknown option, so let it pass */ |
| return 0; |
| } |
| |
| #ifdef DEBUG_MEMORY |
| static void |
| free_option_buffer(void) |
| { |
| free(opt_buffer); |
| } |
| #endif |
| |
| #define get_option_raw(dhcp, opt) get_option(dhcp, opt, NULL, NULL) |
| static const uint8_t * |
| get_option(const struct dhcp_message *dhcp, uint8_t opt, int *len, int *type) |
| { |
| const uint8_t *p = dhcp->options; |
| const uint8_t *e = p + sizeof(dhcp->options); |
| uint8_t l, ol = 0; |
| uint8_t o = 0; |
| uint8_t overl = 0; |
| uint8_t *bp = NULL; |
| const uint8_t *op = NULL; |
| int bl = 0; |
| |
| /* DHCP Options are in TLV format with T and L each being a single |
| * byte. In general, here we have p -> T, ol=p+1 -> L, op -> V. |
| * We must make sure there is enough room to read both T and L. |
| */ |
| while (p + 1 < e) { |
| o = *p++; |
| if (o == opt) { |
| if (op) { |
| if (!opt_buffer) { |
| opt_buffer = xmalloc(sizeof(*dhcp)); |
| #ifdef DEBUG_MEMORY |
| atexit(free_option_buffer); |
| #endif |
| } |
| if (!bp) |
| bp = opt_buffer; |
| memcpy(bp, op, ol); |
| bp += ol; |
| } |
| ol = (p + *p < e) ? *p : e - (p + 1); |
| op = p + 1; |
| bl += ol; |
| } |
| switch (o) { |
| case DHO_PAD: |
| continue; |
| case DHO_END: |
| if (overl & 1) { |
| /* bit 1 set means parse boot file */ |
| overl &= ~1; |
| p = dhcp->bootfile; |
| e = p + sizeof(dhcp->bootfile); |
| } else if (overl & 2) { |
| /* bit 2 set means parse server name */ |
| overl &= ~2; |
| p = dhcp->servername; |
| e = p + sizeof(dhcp->servername); |
| } else |
| goto exit; |
| break; |
| case DHO_OPTIONSOVERLOADED: |
| /* Ensure we only get this option once */ |
| if (!overl) |
| overl = p[1]; |
| break; |
| } |
| l = *p++; |
| p += l; |
| } |
| |
| exit: |
| if (valid_length(opt, bl, type) == -1) { |
| errno = EINVAL; |
| return NULL; |
| } |
| if (len) |
| *len = bl; |
| if (bp) { |
| memcpy(bp, op, ol); |
| return (const uint8_t *)opt_buffer; |
| } |
| if (op) |
| return op; |
| errno = ENOENT; |
| return NULL; |
| } |
| |
| int |
| get_option_addr(struct in_addr *a, const struct dhcp_message *dhcp, |
| uint8_t option) |
| { |
| const uint8_t *p = get_option_raw(dhcp, option); |
| |
| if (!p) |
| return -1; |
| memcpy(&a->s_addr, p, sizeof(a->s_addr)); |
| return 0; |
| } |
| |
| int |
| get_option_uint32(uint32_t *i, const struct dhcp_message *dhcp, uint8_t option) |
| { |
| const uint8_t *p = get_option_raw(dhcp, option); |
| uint32_t d; |
| |
| if (!p) |
| return -1; |
| memcpy(&d, p, sizeof(d)); |
| *i = ntohl(d); |
| return 0; |
| } |
| |
| int |
| get_option_uint16(uint16_t *i, const struct dhcp_message *dhcp, uint8_t option) |
| { |
| const uint8_t *p = get_option_raw(dhcp, option); |
| uint16_t d; |
| |
| if (!p) |
| return -1; |
| memcpy(&d, p, sizeof(d)); |
| *i = ntohs(d); |
| return 0; |
| } |
| |
| int |
| get_option_uint8(uint8_t *i, const struct dhcp_message *dhcp, uint8_t option) |
| { |
| const uint8_t *p = get_option_raw(dhcp, option); |
| |
| if (!p) |
| return -1; |
| if (i) |
| *i = *(p); |
| return 0; |
| } |
| |
| /* Decode an RFC3397 DNS search order option into a space |
| * seperated string. Returns length of string (including |
| * terminating zero) or zero on error. out may be NULL |
| * to just determine output length. */ |
| static ssize_t |
| decode_rfc3397(char *out, ssize_t len, int pl, const uint8_t *p) |
| { |
| const uint8_t *r, *q = p; |
| int count = 0, l, hops; |
| uint8_t ltype; |
| |
| while (q - p < pl) { |
| r = NULL; |
| hops = 0; |
| /* We check we are inside our length again incase |
| * the data is NOT terminated correctly. */ |
| while ((l = *q++) && q - p < pl) { |
| ltype = l & 0xc0; |
| if (ltype == 0x80 || ltype == 0x40) |
| return 0; |
| else if (ltype == 0xc0) { /* pointer */ |
| l = (l & 0x3f) << 8; |
| l |= *q++; |
| /* save source of first jump. */ |
| if (!r) |
| r = q; |
| hops++; |
| if (hops > 255) |
| return 0; |
| q = p + l; |
| if (q - p >= pl) |
| return 0; |
| } else { |
| /* straightforward name segment, add with '.' */ |
| count += l + 1; |
| if (out) { |
| if ((ssize_t)l + 1 > len) { |
| errno = ENOBUFS; |
| return -1; |
| } |
| memcpy(out, q, l); |
| out += l; |
| *out++ = '.'; |
| len -= l; |
| len--; |
| } |
| q += l; |
| } |
| } |
| /* change last dot to space */ |
| if (out) |
| *(out - 1) = ' '; |
| if (r) |
| q = r; |
| } |
| |
| /* change last space to zero terminator */ |
| if (out) |
| *(out - 1) = 0; |
| |
| return count; |
| } |
| |
| static ssize_t |
| decode_rfc3442(char *out, ssize_t len, int pl, const uint8_t *p) |
| { |
| const uint8_t *e; |
| ssize_t b, bytes = 0, ocets; |
| uint8_t cidr; |
| struct in_addr addr; |
| char *o = out; |
| |
| /* Minimum is 5 -first is CIDR and a router length of 4 */ |
| if (pl < 5) { |
| errno = EINVAL; |
| return -1; |
| } |
| |
| e = p + pl; |
| while (p < e) { |
| cidr = *p++; |
| if (cidr > 32) { |
| errno = EINVAL; |
| return -1; |
| } |
| ocets = (cidr + 7) / 8; |
| if (!out) { |
| p += 4 + ocets; |
| bytes += ((4 * 4) * 2) + 4; |
| continue; |
| } |
| if ((((4 * 4) * 2) + 4) > len) { |
| errno = ENOBUFS; |
| return -1; |
| } |
| if (o != out) { |
| *o++ = ' '; |
| len--; |
| } |
| /* If we have ocets then we have a destination and netmask */ |
| if (ocets > 0) { |
| addr.s_addr = 0; |
| memcpy(&addr.s_addr, p, ocets); |
| b = snprintf(o, len, "%s/%d", inet_ntoa(addr), cidr); |
| p += ocets; |
| } else |
| b = snprintf(o, len, "0.0.0.0/0"); |
| o += b; |
| len -= b; |
| |
| /* Finally, snag the router */ |
| memcpy(&addr.s_addr, p, 4); |
| p += 4; |
| b = snprintf(o, len, " %s", inet_ntoa(addr)); |
| o += b; |
| len -= b; |
| } |
| |
| if (out) |
| return o - out; |
| return bytes; |
| } |
| |
| static struct rt * |
| decode_rfc3442_rt(int dl, const uint8_t *data) |
| { |
| const uint8_t *p = data; |
| const uint8_t *e; |
| uint8_t cidr; |
| size_t ocets; |
| struct rt *routes = NULL; |
| struct rt *rt = NULL; |
| |
| /* Minimum is 5 -first is CIDR and a router length of 4 */ |
| if (dl < 5) |
| return NULL; |
| |
| e = p + dl; |
| while (p < e) { |
| cidr = *p++; |
| if (cidr > 32) { |
| free_routes(routes); |
| errno = EINVAL; |
| return NULL; |
| } |
| |
| if (rt) { |
| rt->next = xzalloc(sizeof(*rt)); |
| rt = rt->next; |
| } else { |
| routes = rt = xzalloc(sizeof(*routes)); |
| } |
| rt->next = NULL; |
| |
| ocets = (cidr + 7) / 8; |
| /* If we have ocets then we have a destination and netmask */ |
| if (ocets > 0) { |
| memcpy(&rt->dest.s_addr, p, ocets); |
| p += ocets; |
| rt->net.s_addr = htonl(~0U << (32 - cidr)); |
| } |
| |
| /* Finally, snag the router */ |
| memcpy(&rt->gate.s_addr, p, 4); |
| p += 4; |
| } |
| return routes; |
| } |
| |
| static char * |
| decode_rfc3361(int dl, const uint8_t *data) |
| { |
| uint8_t enc; |
| unsigned int l; |
| char *sip = NULL; |
| struct in_addr addr; |
| char *p; |
| |
| if (dl < 2) { |
| errno = EINVAL; |
| return 0; |
| } |
| |
| enc = *data++; |
| dl--; |
| switch (enc) { |
| case 0: |
| if ((l = decode_rfc3397(NULL, 0, dl, data)) > 0) { |
| sip = xmalloc(l); |
| decode_rfc3397(sip, l, dl, data); |
| } |
| break; |
| case 1: |
| if (dl == 0 || dl % 4 != 0) { |
| errno = EINVAL; |
| break; |
| } |
| addr.s_addr = INADDR_BROADCAST; |
| l = ((dl / sizeof(addr.s_addr)) * ((4 * 4) + 1)) + 1; |
| sip = p = xmalloc(l); |
| while (l != 0) { |
| memcpy(&addr.s_addr, data, sizeof(addr.s_addr)); |
| data += sizeof(addr.s_addr); |
| p += snprintf(p, l - (p - sip), "%s ", inet_ntoa(addr)); |
| l -= sizeof(addr.s_addr); |
| } |
| *--p = '\0'; |
| break; |
| default: |
| errno = EINVAL; |
| return 0; |
| } |
| |
| return sip; |
| } |
| |
| char * |
| get_option_string(const struct dhcp_message *dhcp, uint8_t option) |
| { |
| int type = 0; |
| int len; |
| const uint8_t *p; |
| char *s; |
| |
| p = get_option(dhcp, option, &len, &type); |
| if (!p || *p == '\0') |
| return NULL; |
| |
| if (type & RFC3397) { |
| type = decode_rfc3397(NULL, 0, len, p); |
| if (!type) { |
| errno = EINVAL; |
| return NULL; |
| } |
| s = xmalloc(sizeof(char) * type); |
| decode_rfc3397(s, type, len, p); |
| return s; |
| } |
| |
| if (type & RFC3361) |
| return decode_rfc3361(len, p); |
| |
| s = xmalloc(sizeof(char) * (len + 1)); |
| memcpy(s, p, len); |
| s[len] = '\0'; |
| return s; |
| } |
| |
| /* This calculates the netmask that we should use for static routes. |
| * This IS different from the calculation used to calculate the netmask |
| * for an interface address. */ |
| static uint32_t |
| route_netmask(uint32_t ip_in) |
| { |
| /* used to be unsigned long - check if error */ |
| uint32_t p = ntohl(ip_in); |
| uint32_t t; |
| |
| if (IN_CLASSA(p)) |
| t = ~IN_CLASSA_NET; |
| else { |
| if (IN_CLASSB(p)) |
| t = ~IN_CLASSB_NET; |
| else { |
| if (IN_CLASSC(p)) |
| t = ~IN_CLASSC_NET; |
| else |
| t = 0; |
| } |
| } |
| |
| while (t & p) |
| t >>= 1; |
| |
| return (htonl(~t)); |
| } |
| |
| /* We need to obey routing options. |
| * If we have a CSR then we only use that. |
| * Otherwise we add static routes and then routers. */ |
| struct rt * |
| get_option_routes(const struct dhcp_message *dhcp, |
| const char *ifname, int *opts) |
| { |
| const uint8_t *p; |
| const uint8_t *e; |
| struct rt *routes = NULL; |
| struct rt *route = NULL; |
| int len; |
| |
| /* If we have CSR's then we MUST use these only */ |
| p = get_option(dhcp, DHO_CSR, &len, NULL); |
| /* Check for crappy MS option */ |
| if (!p) |
| p = get_option(dhcp, DHO_MSCSR, &len, NULL); |
| if (p) { |
| routes = decode_rfc3442_rt(len, p); |
| if (routes && !(*opts & DHCPCD_CSR_WARNED)) { |
| syslog(LOG_DEBUG, |
| "%s: using Classless Static Routes (RFC3442)", |
| ifname); |
| *opts |= DHCPCD_CSR_WARNED; |
| return routes; |
| } |
| } |
| |
| /* OK, get our static routes first. */ |
| p = get_option(dhcp, DHO_STATICROUTE, &len, NULL); |
| if (p) { |
| e = p + len; |
| while (p < e) { |
| if (route) { |
| route->next = xmalloc(sizeof(*route)); |
| route = route->next; |
| } else |
| routes = route = xmalloc(sizeof(*routes)); |
| route->next = NULL; |
| memcpy(&route->dest.s_addr, p, 4); |
| p += 4; |
| memcpy(&route->gate.s_addr, p, 4); |
| p += 4; |
| route->net.s_addr = route_netmask(route->dest.s_addr); |
| } |
| } |
| |
| /* Now grab our routers */ |
| p = get_option(dhcp, DHO_ROUTER, &len, NULL); |
| if (p) { |
| e = p + len; |
| while (p < e) { |
| if (route) { |
| route->next = xzalloc(sizeof(*route)); |
| route = route->next; |
| } else |
| routes = route = xzalloc(sizeof(*route)); |
| memcpy(&route->gate.s_addr, p, 4); |
| p += 4; |
| } |
| } |
| |
| return routes; |
| } |
| |
| static size_t |
| encode_rfc1035(const char *src, uint8_t *dst) |
| { |
| uint8_t *p = dst; |
| uint8_t *lp = p++; |
| |
| if (*src == '\0') |
| return 0; |
| for (; *src; src++) { |
| if (*src == '\0') |
| break; |
| if (*src == '.') { |
| /* Skip the trailing . */ |
| if (src[1] == '\0') |
| break; |
| *lp = p - lp - 1; |
| if (*lp == '\0') |
| return p - dst; |
| lp = p++; |
| } else |
| *p++ = (uint8_t)*src; |
| } |
| *lp = p - lp - 1; |
| *p++ = '\0'; |
| return p - dst; |
| } |
| |
| #define PUTADDR(_type, _val) \ |
| { \ |
| *p++ = _type; \ |
| *p++ = 4; \ |
| memcpy(p, &_val.s_addr, 4); \ |
| p += 4; \ |
| } |
| |
| int |
| dhcp_message_add_addr(struct dhcp_message *dhcp, |
| uint8_t type, struct in_addr addr) |
| { |
| uint8_t *p; |
| size_t len; |
| |
| p = dhcp->options; |
| while (*p != DHO_END) { |
| p++; |
| p += *p + 1; |
| } |
| |
| len = p - (uint8_t *)dhcp; |
| if (len + 6 > sizeof(*dhcp)) { |
| errno = ENOMEM; |
| return -1; |
| } |
| |
| PUTADDR(type, addr); |
| *p = DHO_END; |
| return 0; |
| } |
| |
| ssize_t |
| make_message(struct dhcp_message **message, |
| const struct interface *iface, |
| uint8_t type) |
| { |
| struct dhcp_message *dhcp; |
| uint8_t *m, *lp, *p; |
| uint8_t *n_params = NULL; |
| time_t up = uptime() - iface->start_uptime; |
| uint32_t ul; |
| uint16_t sz; |
| size_t len; |
| const char *hp; |
| const struct dhcp_opt *opt; |
| const struct if_options *ifo = iface->state->options; |
| const struct dhcp_lease *lease = &iface->state->lease; |
| |
| dhcp = xzalloc(sizeof (*dhcp)); |
| m = (uint8_t *)dhcp; |
| p = dhcp->options; |
| |
| if ((type == DHCP_INFORM || |
| type == DHCP_RELEASE || |
| type == DHCP_REQUEST) && |
| !IN_LINKLOCAL(ntohl(iface->addr.s_addr))) |
| { |
| dhcp->ciaddr = iface->addr.s_addr; |
| /* In-case we haven't actually configured the address yet */ |
| if (type == DHCP_INFORM && iface->addr.s_addr == 0) |
| dhcp->ciaddr = lease->addr.s_addr; |
| /* Zero the address if we're currently on a different subnet */ |
| if (type == DHCP_REQUEST && |
| iface->net.s_addr != lease->net.s_addr) |
| dhcp->ciaddr = 0; |
| } |
| |
| dhcp->op = DHCP_BOOTREQUEST; |
| dhcp->hwtype = iface->family; |
| switch (iface->family) { |
| case ARPHRD_ETHER: |
| case ARPHRD_IEEE802: |
| dhcp->hwlen = ETHER_ADDR_LEN; |
| memcpy(&dhcp->chaddr, &iface->hwaddr, ETHER_ADDR_LEN); |
| break; |
| case ARPHRD_IEEE1394: |
| case ARPHRD_INFINIBAND: |
| dhcp->hwlen = 0; |
| if (dhcp->ciaddr == 0 && |
| type != DHCP_DECLINE && type != DHCP_RELEASE) |
| dhcp->flags = htons(BROADCAST_FLAG); |
| break; |
| } |
| |
| if (type != DHCP_DECLINE && type != DHCP_RELEASE) { |
| if (up < 0 || up > (time_t)UINT16_MAX) |
| dhcp->secs = htons((uint16_t)UINT16_MAX); |
| else |
| dhcp->secs = htons(up); |
| } |
| dhcp->xid = iface->state->xid; |
| dhcp->cookie = htonl(MAGIC_COOKIE); |
| |
| *p++ = DHO_MESSAGETYPE; |
| *p++ = 1; |
| *p++ = type; |
| |
| if (iface->clientid) { |
| *p++ = DHO_CLIENTID; |
| memcpy(p, iface->clientid, iface->clientid[0] + 1); |
| p += iface->clientid[0] + 1; |
| } |
| |
| if (lease->addr.s_addr && !IN_LINKLOCAL(htonl(lease->addr.s_addr))) { |
| if (type == DHCP_DECLINE || |
| type == DHCP_DISCOVER || |
| (type == DHCP_REQUEST && |
| lease->addr.s_addr != iface->addr.s_addr)) |
| { |
| PUTADDR(DHO_IPADDRESS, lease->addr); |
| if (lease->server.s_addr) |
| PUTADDR(DHO_SERVERID, lease->server); |
| } |
| |
| if (type == DHCP_RELEASE) { |
| if (lease->server.s_addr) |
| PUTADDR(DHO_SERVERID, lease->server); |
| } |
| } |
| |
| if (type == DHCP_DECLINE) { |
| *p++ = DHO_MESSAGE; |
| len = strlen(DAD); |
| *p++ = len; |
| memcpy(p, DAD, len); |
| p += len; |
| } |
| |
| if (type == DHCP_DISCOVER || |
| type == DHCP_INFORM || |
| type == DHCP_REQUEST) |
| { |
| *p++ = DHO_MAXMESSAGESIZE; |
| *p++ = 2; |
| sz = get_mtu(iface->name); |
| if (sz < MTU_MIN) { |
| if (set_mtu(iface->name, MTU_MIN) == 0) |
| sz = MTU_MIN; |
| } else if (sz > MTU_MAX) { |
| /* Even though our MTU could be greater than |
| * MTU_MAX (1500) dhcpcd does not presently |
| * handle DHCP packets any bigger. */ |
| sz = MTU_MAX; |
| } |
| sz = htons(sz); |
| memcpy(p, &sz, 2); |
| p += 2; |
| |
| if (ifo->userclass[0]) { |
| *p++ = DHO_USERCLASS; |
| memcpy(p, ifo->userclass, ifo->userclass[0] + 1); |
| p += ifo->userclass[0] + 1; |
| } |
| |
| if (ifo->vendorclassid[0]) { |
| *p++ = DHO_VENDORCLASSID; |
| memcpy(p, ifo->vendorclassid, |
| ifo->vendorclassid[0] + 1); |
| p += ifo->vendorclassid[0] + 1; |
| } |
| |
| |
| if (type != DHCP_INFORM) { |
| if (ifo->leasetime != 0) { |
| *p++ = DHO_LEASETIME; |
| *p++ = 4; |
| ul = htonl(ifo->leasetime); |
| memcpy(p, &ul, 4); |
| p += 4; |
| } |
| } |
| |
| /* Regardless of RFC2132, we should always send a hostname |
| * upto the first dot (the short hostname) as otherwise |
| * confuses some DHCP servers when updating DNS. |
| * The FQDN option should be used if a FQDN is required. */ |
| if (ifo->options & DHCPCD_HOSTNAME && ifo->hostname[0]) { |
| *p++ = DHO_HOSTNAME; |
| hp = strchr(ifo->hostname, '.'); |
| if (hp) |
| len = hp - ifo->hostname; |
| else |
| len = strlen(ifo->hostname); |
| *p++ = len; |
| memcpy(p, ifo->hostname, len); |
| p += len; |
| } |
| if (ifo->fqdn != FQDN_DISABLE && ifo->hostname[0]) { |
| /* IETF DHC-FQDN option (81), RFC4702 */ |
| *p++ = DHO_FQDN; |
| lp = p; |
| *p++ = 3; |
| /* |
| * Flags: 0000NEOS |
| * S: 1 => Client requests Server to update |
| * a RR in DNS as well as PTR |
| * O: 1 => Server indicates to client that |
| * DNS has been updated |
| * E: 1 => Name data is DNS format |
| * N: 1 => Client requests Server to not |
| * update DNS |
| */ |
| *p++ = (ifo->fqdn & 0x09) | 0x04; |
| *p++ = 0; /* from server for PTR RR */ |
| *p++ = 0; /* from server for A RR if S=1 */ |
| ul = encode_rfc1035(ifo->hostname, p); |
| *lp += ul; |
| p += ul; |
| } |
| |
| /* vendor is already encoded correctly, so just add it */ |
| if (ifo->vendor[0]) { |
| *p++ = DHO_VENDOR; |
| memcpy(p, ifo->vendor, ifo->vendor[0] + 1); |
| p += ifo->vendor[0] + 1; |
| } |
| |
| *p++ = DHO_PARAMETERREQUESTLIST; |
| n_params = p; |
| *p++ = 0; |
| for (opt = dhcp_opts; opt->option; opt++) { |
| if (!(opt->type & REQUEST || |
| has_option_mask(ifo->requestmask, opt->option))) |
| continue; |
| if (type == DHCP_INFORM && |
| (opt->option == DHO_RENEWALTIME || |
| opt->option == DHO_REBINDTIME)) |
| continue; |
| *p++ = opt->option; |
| } |
| *n_params = p - n_params - 1; |
| } |
| *p++ = DHO_END; |
| |
| #ifdef BOOTP_MESSAGE_LENTH_MIN |
| /* Some crappy DHCP servers think they have to obey the BOOTP minimum |
| * message length. |
| * They are wrong, but we should still cater for them. */ |
| while (p - m < BOOTP_MESSAGE_LENTH_MIN) |
| *p++ = DHO_PAD; |
| #endif |
| |
| *message = dhcp; |
| return p - m; |
| } |
| |
| ssize_t |
| write_lease(const struct interface *iface, const struct dhcp_message *dhcp) |
| { |
| int fd; |
| ssize_t bytes = sizeof(*dhcp); |
| const uint8_t *p = dhcp->options; |
| const uint8_t *e = p + sizeof(dhcp->options); |
| uint8_t write_buffer[sizeof(*dhcp) + sizeof(iface->server_info) + 1]; |
| uint8_t l; |
| uint8_t o = 0; |
| uint8_t *w; |
| |
| /* We don't write BOOTP leases */ |
| if (is_bootp(dhcp)) { |
| unlink(iface->leasefile); |
| return 0; |
| } |
| |
| syslog(LOG_DEBUG, "%s: writing lease `%s'", |
| iface->name, iface->leasefile); |
| |
| fd = open(iface->leasefile, O_WRONLY | O_CREAT | O_TRUNC, 0600); |
| if (fd == -1) { |
| syslog(LOG_ERR, "%s: open: %m", iface->name); |
| return -1; |
| } |
| |
| /* Only write as much as we need */ |
| while (p < e) { |
| o = *p; |
| if (o == DHO_END) { |
| bytes = p - (const uint8_t *)dhcp; |
| break; |
| } |
| p++; |
| if (o != DHO_PAD) { |
| l = *p++; |
| p += l; |
| } |
| } |
| |
| memcpy(write_buffer, dhcp, bytes); |
| w = write_buffer + bytes; |
| |
| /* Copy in server info if this is available. */ |
| if (iface->server_info.gw_hwlen != 0) { |
| *w++ = DHO_END; |
| memcpy(w, &iface->server_info, sizeof(iface->server_info)); |
| bytes += sizeof(iface->server_info) + 1; |
| } |
| |
| bytes = write(fd, write_buffer, bytes); |
| close(fd); |
| return bytes; |
| } |
| |
| ssize_t |
| read_lease(struct interface *iface, struct dhcp_message **dhcpp) |
| { |
| int fd; |
| uint8_t read_buffer[sizeof(**dhcpp) + sizeof(iface->server_info)]; |
| const uint8_t *options_startp = |
| read_buffer + offsetof(struct dhcp_message, options); |
| const uint8_t *options_endp = options_startp + |
| sizeof((*dhcpp)->options); |
| uint8_t option_len; |
| uint8_t option_type = 0; |
| ssize_t bytes; |
| |
| if (*dhcpp != NULL) { |
| free(*dhcpp); |
| *dhcpp = NULL; |
| } |
| memset(&iface->server_info, 0, sizeof(iface->server_info)); |
| |
| fd = open(iface->leasefile, O_RDONLY); |
| if (fd == -1) { |
| if (errno != ENOENT) |
| syslog(LOG_ERR, "%s: open `%s': %m", |
| iface->name, iface->leasefile); |
| return 0; |
| } |
| syslog(LOG_DEBUG, "%s: reading lease `%s'", |
| iface->name, iface->leasefile); |
| bytes = read(fd, read_buffer, sizeof(read_buffer)); |
| close(fd); |
| |
| /* Lease file should at minimum contain all fields before options. */ |
| if (read_buffer + bytes < options_startp) |
| return 0; |
| |
| *dhcpp = xmalloc(sizeof(**dhcpp)); |
| memset(*dhcpp, 0, sizeof(**dhcpp)); |
| |
| if (options_endp > read_buffer + bytes) |
| options_endp = read_buffer + bytes; |
| |
| while (options_startp < options_endp) { |
| option_type = *options_startp++; |
| if (option_type == DHO_END) |
| break; |
| if (option_type != DHO_PAD) { |
| option_len = *options_startp++; |
| options_startp += option_len; |
| } |
| } |
| memcpy(*dhcpp, read_buffer, options_startp - read_buffer); |
| |
| /* |
| * DHCP server information is stored after the DHO_END character |
| * in the lease file. The first byte of the server information |
| * is the length of the gateway hardware address. |
| */ |
| options_endp = read_buffer + bytes; |
| if (options_startp >= options_endp || |
| options_startp + sizeof(iface->server_info) > options_endp) |
| return bytes; |
| |
| syslog(LOG_DEBUG, "%s: found server info in lease `%s'", |
| iface->name, iface->leasefile); |
| |
| memcpy(&iface->server_info, options_startp, sizeof(iface->server_info)); |
| if (iface->server_info.gw_hwlen != iface->hwlen) { |
| syslog(LOG_ERR, "%s: lease file %s has incompatible MAC address" |
| " length %d (expected %zd)", iface->name, |
| iface->leasefile, iface->server_info.gw_hwlen, |
| iface->hwlen); |
| memset(&iface->server_info, 0, sizeof(iface->server_info)); |
| } |
| |
| return bytes; |
| } |
| |
| static ssize_t |
| print_string(char *s, ssize_t len, int dl, const uint8_t *data) |
| { |
| uint8_t c; |
| const uint8_t *e, *p; |
| ssize_t bytes = 0; |
| ssize_t r; |
| |
| e = data + dl; |
| while (data < e) { |
| c = *data++; |
| if (c == '\0') { |
| /* If rest is all NULL, skip it. */ |
| for (p = data; p < e; p++) |
| if (*p != '\0') |
| break; |
| if (p == e) |
| break; |
| } |
| if (!isascii(c) || !isprint(c)) { |
| if (s) { |
| if (len < 5) { |
| errno = ENOBUFS; |
| return -1; |
| } |
| r = snprintf(s, len, "\\%03o", c); |
| len -= r; |
| bytes += r; |
| s += r; |
| } else |
| bytes += 4; |
| continue; |
| } |
| switch (c) { |
| case '"': /* FALLTHROUGH */ |
| case '\'': /* FALLTHROUGH */ |
| case '$': /* FALLTHROUGH */ |
| case '`': /* FALLTHROUGH */ |
| case '\\': /* FALLTHROUGH */ |
| case '|': /* FALLTHROUGH */ |
| case '&': |
| if (s) { |
| if (len < 3) { |
| errno = ENOBUFS; |
| return -1; |
| } |
| *s++ = '\\'; |
| len--; |
| } |
| bytes++; |
| break; |
| } |
| if (s) { |
| *s++ = c; |
| len--; |
| } |
| bytes++; |
| } |
| |
| /* NULL */ |
| if (s) |
| *s = '\0'; |
| bytes++; |
| return bytes; |
| } |
| |
| static ssize_t |
| print_option(char *s, ssize_t len, int type, int dl, const uint8_t *data) |
| { |
| const uint8_t *e, *t; |
| uint16_t u16; |
| int16_t s16; |
| uint32_t u32; |
| int32_t s32; |
| struct in_addr addr; |
| ssize_t bytes = 0; |
| ssize_t l; |
| char *tmp; |
| |
| if (type & RFC3397) { |
| l = decode_rfc3397(NULL, 0, dl, data); |
| if (l < 1) |
| return l; |
| tmp = xmalloc(l); |
| decode_rfc3397(tmp, l, dl, data); |
| l = print_string(s, len, l - 1, (uint8_t *)tmp); |
| free(tmp); |
| return l; |
| } |
| |
| if (type & RFC3442) |
| return decode_rfc3442(s, len, dl, data); |
| |
| if (type & STRING) { |
| /* Some DHCP servers return NULL strings */ |
| if (*data == '\0') |
| return 0; |
| return print_string(s, len, dl, data); |
| } |
| |
| if (!s) { |
| if (type & UINT8) |
| l = 3; |
| else if (type & UINT16) { |
| l = 5; |
| dl /= 2; |
| } else if (type & SINT16) { |
| l = 6; |
| dl /= 2; |
| } else if (type & UINT32) { |
| l = 10; |
| dl /= 4; |
| } else if (type & SINT32) { |
| l = 11; |
| dl /= 4; |
| } else if (type & IPV4) { |
| l = 16; |
| dl /= 4; |
| } else { |
| errno = EINVAL; |
| return -1; |
| } |
| return (l + 1) * dl; |
| } |
| |
| t = data; |
| e = data + dl; |
| while (data < e) { |
| if (data != t) { |
| *s++ = ' '; |
| bytes++; |
| len--; |
| } |
| if (type & UINT8) { |
| l = snprintf(s, len, "%d", *data); |
| data++; |
| } else if (type & UINT16) { |
| memcpy(&u16, data, sizeof(u16)); |
| u16 = ntohs(u16); |
| l = snprintf(s, len, "%d", u16); |
| data += sizeof(u16); |
| } else if (type & SINT16) { |
| memcpy(&s16, data, sizeof(s16)); |
| s16 = ntohs(s16); |
| l = snprintf(s, len, "%d", s16); |
| data += sizeof(s16); |
| } else if (type & UINT32) { |
| memcpy(&u32, data, sizeof(u32)); |
| u32 = ntohl(u32); |
| l = snprintf(s, len, "%d", u32); |
| data += sizeof(u32); |
| } else if (type & SINT32) { |
| memcpy(&s32, data, sizeof(s32)); |
| s32 = ntohl(s32); |
| l = snprintf(s, len, "%d", s32); |
| data += sizeof(s32); |
| } else if (type & IPV4) { |
| memcpy(&addr.s_addr, data, sizeof(addr.s_addr)); |
| l = snprintf(s, len, "%s", inet_ntoa(addr)); |
| data += sizeof(addr.s_addr); |
| } else |
| l = 0; |
| if (len <= l) { |
| bytes += len; |
| break; |
| } |
| len -= l; |
| bytes += l; |
| s += l; |
| } |
| |
| return bytes; |
| } |
| |
| static void |
| setvar(char ***e, const char *prefix, const char *var, const char *value) |
| { |
| size_t len = strlen(prefix) + strlen(var) + strlen(value) + 4; |
| |
| **e = xmalloc(len); |
| snprintf(**e, len, "%s_%s=%s", prefix, var, value); |
| (*e)++; |
| } |
| |
| ssize_t |
| configure_env(char **env, const char *prefix, const struct dhcp_message *dhcp, |
| const struct if_options *ifo) |
| { |
| unsigned int i; |
| const uint8_t *p; |
| int pl; |
| struct in_addr addr; |
| struct in_addr net; |
| struct in_addr brd; |
| char *val, *v; |
| const struct dhcp_opt *opt; |
| ssize_t len, e = 0; |
| char **ep; |
| char cidr[4]; |
| uint8_t overl = 0; |
| |
| get_option_uint8(&overl, dhcp, DHO_OPTIONSOVERLOADED); |
| |
| if (!env) { |
| for (opt = dhcp_opts; opt->option; opt++) { |
| if (!opt->var) |
| continue; |
| if (has_option_mask(ifo->nomask, opt->option)) |
| continue; |
| if (get_option_raw(dhcp, opt->option)) |
| e++; |
| } |
| if (dhcp->yiaddr || dhcp->ciaddr) |
| e += 5; |
| if (*dhcp->bootfile && !(overl & 1)) |
| e++; |
| if (*dhcp->servername && !(overl & 2)) |
| e++; |
| return e; |
| } |
| |
| ep = env; |
| if (dhcp->yiaddr || dhcp->ciaddr) { |
| /* Set some useful variables that we derive from the DHCP |
| * message but are not necessarily in the options */ |
| addr.s_addr = dhcp->yiaddr ? dhcp->yiaddr : dhcp->ciaddr; |
| setvar(&ep, prefix, "ip_address", inet_ntoa(addr)); |
| if (get_option_addr(&net, dhcp, DHO_SUBNETMASK) == -1) { |
| net.s_addr = get_netmask(addr.s_addr); |
| setvar(&ep, prefix, "subnet_mask", inet_ntoa(net)); |
| } |
| i = inet_ntocidr(net); |
| snprintf(cidr, sizeof(cidr), "%d", inet_ntocidr(net)); |
| setvar(&ep, prefix, "subnet_cidr", cidr); |
| if (get_option_addr(&brd, dhcp, DHO_BROADCAST) == -1) { |
| brd.s_addr = addr.s_addr | ~net.s_addr; |
| setvar(&ep, prefix, "broadcast_address", inet_ntoa(brd)); |
| } |
| addr.s_addr = dhcp->yiaddr & net.s_addr; |
| setvar(&ep, prefix, "network_number", inet_ntoa(addr)); |
| } |
| |
| if (*dhcp->bootfile && !(overl & 1)) |
| setvar(&ep, prefix, "filename", (const char *)dhcp->bootfile); |
| if (*dhcp->servername && !(overl & 2)) |
| setvar(&ep, prefix, "server_name", (const char *)dhcp->servername); |
| |
| for (opt = dhcp_opts; opt->option; opt++) { |
| if (!opt->var) |
| continue; |
| if (has_option_mask(ifo->nomask, opt->option)) |
| continue; |
| val = NULL; |
| p = get_option(dhcp, opt->option, &pl, NULL); |
| if (!p) |
| continue; |
| /* We only want the FQDN name */ |
| if (opt->option == DHO_FQDN) { |
| p += 3; |
| pl -= 3; |
| } |
| len = print_option(NULL, 0, opt->type, pl, p); |
| if (len < 0) |
| return -1; |
| e = strlen(prefix) + strlen(opt->var) + len + 4; |
| v = val = *ep++ = xmalloc(e); |
| v += snprintf(val, e, "%s_%s=", prefix, opt->var); |
| if (len != 0) |
| print_option(v, len, opt->type, pl, p); |
| } |
| |
| return ep - env; |
| } |
| |
| void |
| get_lease(struct dhcp_lease *lease, const struct dhcp_message *dhcp) |
| { |
| struct timeval now; |
| |
| /* BOOTP does not set yiaddr for replies when ciaddr is set. */ |
| if (dhcp->yiaddr) |
| lease->addr.s_addr = dhcp->yiaddr; |
| else |
| lease->addr.s_addr = dhcp->ciaddr; |
| if (get_option_addr(&lease->net, dhcp, DHO_SUBNETMASK) == -1) |
| lease->net.s_addr = get_netmask(lease->addr.s_addr); |
| if (get_option_addr(&lease->brd, dhcp, DHO_BROADCAST) == -1) |
| lease->brd.s_addr = lease->addr.s_addr | ~lease->net.s_addr; |
| if (get_option_uint32(&lease->leasetime, dhcp, DHO_LEASETIME) == 0) { |
| /* Ensure that we can use the lease */ |
| get_monotonic(&now); |
| if (now.tv_sec + (time_t)lease->leasetime < now.tv_sec) |
| lease->leasetime = ~0U; /* Infinite lease */ |
| } else |
| lease->leasetime = ~0U; /* Default to infinite lease */ |
| if (get_option_uint32(&lease->renewaltime, dhcp, DHO_RENEWALTIME) != 0) |
| lease->renewaltime = 0; |
| if (get_option_uint32(&lease->rebindtime, dhcp, DHO_REBINDTIME) != 0) |
| lease->rebindtime = 0; |
| if (get_option_addr(&lease->server, dhcp, DHO_SERVERID) != 0) |
| lease->server.s_addr = INADDR_ANY; |
| } |
| |
| void init_option_iterator(const struct dhcp_message *message, |
| struct dhcp_option_iterator *iterator) |
| { |
| iterator->message = message; |
| iterator->ptr = message->options; |
| iterator->end = iterator->ptr + sizeof(message->options); |
| iterator->extra_option_locations = 0; |
| iterator->extra_option_locations_set = 0; |
| } |
| |
| int iterate_next_option(struct dhcp_option_iterator *iterator, |
| uint8_t *option, uint8_t *length, const uint8_t **value) |
| { |
| uint8_t option_code; |
| uint8_t option_len; |
| |
| /* Process special DHO_PAD and DHO_END opcodes. */ |
| while (iterator->ptr < iterator->end) { |
| if (*iterator->ptr == DHO_PAD) { |
| iterator->ptr++; |
| continue; |
| } |
| |
| if (*iterator->ptr != DHO_END) |
| break; |
| |
| if (iterator->extra_option_locations & |
| OPTION_OVERLOADED_BOOT_FILE) { |
| iterator->extra_option_locations &= |
| ~OPTION_OVERLOADED_BOOT_FILE; |
| iterator->ptr = iterator->message->bootfile; |
| iterator->end = iterator->ptr + |
| sizeof(iterator->message->bootfile); |
| } else if (iterator->extra_option_locations & |
| OPTION_OVERLOADED_SERVER_NAME) { |
| iterator->extra_option_locations &= |
| ~OPTION_OVERLOADED_SERVER_NAME; |
| iterator->ptr = iterator->message->servername; |
| iterator->end = iterator->ptr + |
| sizeof(iterator->message->servername); |
| } else |
| return 0; |
| } |
| |
| if (iterator->ptr + 2 > iterator->end) |
| return 0; |
| |
| option_code = *iterator->ptr++; |
| option_len = *iterator->ptr++; |
| if (iterator->ptr + option_len > iterator->end) |
| return 0; |
| |
| if (option_code == DHO_OPTIONSOVERLOADED && option_len > 0 && |
| !iterator->extra_option_locations_set) { |
| iterator->extra_option_locations = *iterator->ptr; |
| iterator->extra_option_locations_set = 1; |
| } |
| |
| if (option) |
| *option = option_code; |
| if (length) |
| *length = option_len; |
| if (value) |
| *value = iterator->ptr; |
| |
| iterator->ptr += option_len; |
| |
| return 1; |
| } |
| |
| void merge_option_values(const struct dhcp_message *src, |
| struct dhcp_message *dst, uint8_t *copy_options) |
| { |
| uint8_t supplied_options[OPTION_MASK_SIZE]; |
| struct dhcp_option_iterator dst_iterator; |
| struct dhcp_option_iterator src_iterator; |
| uint8_t option; |
| const uint8_t *option_value; |
| uint8_t option_length; |
| uint8_t *out; |
| const uint8_t *out_end; |
| int added_options = 0; |
| |
| /* Traverse the destination message for options already supplied. */ |
| memset(&supplied_options, 0, sizeof(supplied_options)); |
| init_option_iterator(dst, &dst_iterator); |
| while (iterate_next_option(&dst_iterator, &option, NULL, NULL)) { |
| add_option_mask(supplied_options, option); |
| } |
| |
| /* We will start merging options at the end of the last block |
| * the iterator traversed to. The const cast below is safe since |
| * this points to data within the (non-const) dst message. */ |
| out = (uint8_t *) dst_iterator.ptr; |
| out_end = dst_iterator.end; |
| |
| init_option_iterator(src, &src_iterator); |
| while (iterate_next_option(&src_iterator, &option, &option_length, |
| &option_value)) { |
| if (has_option_mask(supplied_options, option) || |
| !has_option_mask(copy_options, option)) |
| continue; |
| /* We need space for this option, plus a trailing DHO_END. */ |
| if (out + option_length + 3 > out_end) { |
| syslog(LOG_ERR, |
| "%s: unable to fit option %d (length %d)", |
| __func__, option, option_length); |
| continue; |
| } |
| *out++ = option; |
| *out++ = option_length; |
| memcpy(out, option_value, option_length); |
| out += option_length; |
| added_options++; |
| } |
| |
| if (added_options) { |
| *out++ = DHO_END; |
| syslog(LOG_INFO, "carrying over %d options from original offer", |
| added_options); |
| } |
| } |