X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Fudhcp%2Fdhcpc.c;h=102178a4f94e18be637a06c193337a28e44960ce;hb=d30d1ebc117db182a6156df182057291d6fbaae1;hp=d1e40ee6517daf8f5dd54bc6191c215990f94cbb;hpb=42816c204d2c592a86498c3d3b215c9b4d80e9e1;p=oweals%2Fbusybox.git diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c index d1e40ee65..102178a4f 100644 --- a/networking/udhcp/dhcpc.c +++ b/networking/udhcp/dhcpc.c @@ -1,7 +1,6 @@ /* vi: set sw=4 ts=4: */ /* * udhcp client - * * Russ Dill July 2001 * * This program is free software; you can redistribute it and/or modify @@ -18,6 +17,13 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ +//applet:IF_UDHCPC(APPLET(udhcpc, BB_DIR_SBIN, BB_SUID_DROP)) + +//kbuild:lib-$(CONFIG_UDHCPC) += common.o packet.o signalpipe.o socket.o +//kbuild:lib-$(CONFIG_UDHCPC) += dhcpc.o +//kbuild:lib-$(CONFIG_FEATURE_UDHCPC_ARPING) += arpping.o +//kbuild:lib-$(CONFIG_FEATURE_UDHCP_RFC3397) += domain_codec.o + #include /* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */ #define WANT_PIDFILE 1 @@ -26,10 +32,24 @@ #include "dhcpc.h" #include -#include #include +#include + +#ifndef PACKET_AUXDATA +# define PACKET_AUXDATA 8 +struct tpacket_auxdata { + uint32_t tp_status; + uint32_t tp_len; + uint32_t tp_snaplen; + uint16_t tp_mac; + uint16_t tp_net; + uint16_t tp_vlan_tci; + uint16_t tp_padding; +}; +#endif + -/* struct client_config_t client_config is in bb_common_bufsiz1 */ +/* "struct client_data_t client_data" is in bb_common_bufsiz1 */ #if ENABLE_LONG_OPTS @@ -46,16 +66,17 @@ static const char udhcpc_longopts[] ALIGN1 = "request\0" Required_argument "r" "script\0" Required_argument "s" "timeout\0" Required_argument "T" - "version\0" No_argument "v" "retries\0" Required_argument "t" "tryagain\0" Required_argument "A" "syslog\0" No_argument "S" "request-option\0" Required_argument "O" "no-default-options\0" No_argument "o" "foreground\0" No_argument "f" + USE_FOR_MMU( "background\0" No_argument "b" + ) "broadcast\0" No_argument "B" - IF_FEATURE_UDHCPC_ARPING("arping\0" No_argument "a") + IF_FEATURE_UDHCPC_ARPING("arping\0" Optional_argument "a") IF_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P") ; #endif @@ -96,12 +117,13 @@ enum { /*** Script execution code ***/ /* get a rough idea of how long an option will be (rounding up...) */ -static const uint8_t len_of_option_as_string[] = { +static const uint8_t len_of_option_as_string[] ALIGN1 = { [OPTION_IP ] = sizeof("255.255.255.255 "), [OPTION_IP_PAIR ] = sizeof("255.255.255.255 ") * 2, [OPTION_STATIC_ROUTES ] = sizeof("255.255.255.255/32 255.255.255.255 "), - [OPTION_6RD ] = sizeof("32 128 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff 255.255.255.255 "), + [OPTION_6RD ] = sizeof("132 128 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff 255.255.255.255 "), [OPTION_STRING ] = 1, + [OPTION_STRING_HOST ] = 1, #if ENABLE_FEATURE_UDHCP_RFC3397 [OPTION_DNS_STRING ] = 1, /* unused */ /* Hmmm, this severely overestimates size if SIP_SERVERS option @@ -124,24 +146,6 @@ static int sprint_nip(char *dest, const char *pre, const uint8_t *ip) return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]); } -static int sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip) -{ - char hexstrbuf[16 * 2]; - bin2hex(hexstrbuf, (void*)ip, 16); - return sprintf(dest, /* "%s" */ - "%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s", - /* pre, */ - hexstrbuf + 0 * 4, - hexstrbuf + 1 * 4, - hexstrbuf + 2 * 4, - hexstrbuf + 3 * 4, - hexstrbuf + 4 * 4, - hexstrbuf + 5 * 4, - hexstrbuf + 6 * 4, - hexstrbuf + 7 * 4 - ); -} - /* really simple implementation, just count the bits */ static int mton(uint32_t mask) { @@ -154,6 +158,33 @@ static int mton(uint32_t mask) return i; } +#if ENABLE_FEATURE_UDHCPC_SANITIZEOPT +/* Check if a given name represents a valid DNS name */ +/* See RFC1035, 2.3.1 */ +/* We don't need to be particularly anal. For example, allowing _, hyphen + * at the end, or leading and trailing dots would be ok, since it + * can't be used for attacks. (Leading hyphen can be, if someone uses cmd "$hostname" + * in the script: then hostname may be treated as an option) + */ +static int good_hostname(const char *name) +{ + if (*name == '-') /* Can't start with '-' */ + return 0; + + while (*name) { + unsigned char ch = *name++; + if (!isalnum(ch)) + /* DNS allows only '-', but we are more permissive */ + if (ch != '-' && ch != '_' && ch != '.') + return 0; + // TODO: do we want to validate lengths against NS_MAXLABEL and NS_MAXDNAME? + } + return 1; +} +#else +# define good_hostname(name) 1 +#endif + /* Create "opt_name=opt_value" string */ static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_optflag *optflag, const char *opt_name) { @@ -161,28 +192,24 @@ static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_ int len, type, optlen; char *dest, *ret; - /* option points to OPT_DATA, need to go back and get OPT_LEN */ - len = option[OPT_LEN - OPT_DATA]; + /* option points to OPT_DATA, need to go back to get OPT_LEN */ + len = option[-OPT_DATA + OPT_LEN]; type = optflag->flags & OPTION_TYPE_MASK; optlen = dhcp_option_lengths[type]; upper_length = len_of_option_as_string[type] - * ((unsigned)(len + optlen - 1) / (unsigned)optlen); + * ((unsigned)(len + optlen) / (unsigned)optlen); dest = ret = xmalloc(upper_length + strlen(opt_name) + 2); dest += sprintf(ret, "%s=", opt_name); while (len >= optlen) { - unsigned ip_ofs = 0; - switch (type) { + case OPTION_IP: case OPTION_IP_PAIR: dest += sprint_nip(dest, "", option); - *dest++ = '/'; - ip_ofs = 4; - /* fall through */ - case OPTION_IP: - dest += sprint_nip(dest, "", option + ip_ofs); + if (type == OPTION_IP_PAIR) + dest += sprint_nip(dest, "/", option + 4); break; // case OPTION_BOOLEAN: // dest += sprintf(dest, *option ? "yes" : "no"); @@ -204,10 +231,23 @@ static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_ dest += sprintf(dest, type == OPTION_U32 ? "%lu" : "%ld", (unsigned long) ntohl(val_u32)); break; } + /* Note: options which use 'return' instead of 'break' + * (for example, OPTION_STRING) skip the code which handles + * the case of list of options. + */ case OPTION_STRING: + case OPTION_STRING_HOST: memcpy(dest, option, len); dest[len] = '\0'; - return ret; /* Short circuit this case */ +//TODO: it appears option 15 DHCP_DOMAIN_NAME is often abused +//by DHCP admins to contain a space-separated list of domains, +//not one domain name (presumably, to work as list of search domains, +//instead of using proper option 119 DHCP_DOMAIN_SEARCH). +//Currently, good_hostname() balks on strings containing spaces. +//Do we need to allow it? Only for DHCP_DOMAIN_NAME option? + if (type == OPTION_STRING_HOST && !good_hostname(dest)) + safe_strncpy(dest, "bad", len); + return ret; case OPTION_STATIC_ROUTES: { /* Option binary format: * mask [one byte, 0..32] @@ -252,39 +292,29 @@ static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_ return ret; } - case OPTION_6RD: { + case OPTION_6RD: /* Option binary format (see RFC 5969): - * 0 1 2 3 - * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | OPTION_6RD | option-length | IPv4MaskLen | 6rdPrefixLen | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * | | * | 6rdPrefix | - * | (16 octets) | - * | | - * | | - * | | + * ... (16 octets) ... * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * | 6rdBRIPv4Address(es) | - * . . - * . . - * . . + * ... 6rdBRIPv4Address(es) ... * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * * We convert it to a string * "IPv4MaskLen 6rdPrefixLen 6rdPrefix 6rdBRIPv4Address..." - */ - - /* Sanity check: ensure that our length is at least 22 bytes, that + * + * Sanity check: ensure that our length is at least 22 bytes, that * IPv4MaskLen <= 32, * 6rdPrefixLen <= 128, * 6rdPrefixLen + (32 - IPv4MaskLen) <= 128 - * (2nd condition need no check - it follows from 1st and 3rd). - * If any of these requirements is not fulfilled, return with empty - * value. + * (2nd condition needs no check - it follows from 1st and 3rd). + * Else, return envvar with empty value ("optname=") */ - if (len >= 22 + if (len >= (1 + 1 + 16 + 4) && option[0] <= 32 && (option[1] + 32 - option[0]) <= 128 ) { @@ -296,18 +326,14 @@ static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_ dest += sprint_nip6(dest, /* "", */ option); option += 16; len -= 1 + 1 + 16; - /* 6rdBRIPv4Address(es) */ - while (1) { - dest += sprint_nip(dest, " ", option); - option += 4; - len -= 4; - if (len < 0) - break; - } + *dest++ = ' '; + /* 6rdBRIPv4Address(es), use common IPv4 logic to process them */ + type = OPTION_IP; + optlen = 4; + continue; } return ret; - } #if ENABLE_FEATURE_UDHCP_RFC3397 case OPTION_DNS_STRING: /* unpack option into dest; use ret for prefix (i.e., "optname=") */ @@ -326,37 +352,37 @@ static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_ */ option++; len--; + if (option[-1] == 1) { + /* use common IPv4 logic to process IP addrs */ + type = OPTION_IP; + optlen = 4; + continue; + } if (option[-1] == 0) { dest = dname_dec(option, len, ret); if (dest) { free(ret); return dest; } - } else - if (option[-1] == 1) { - const char *pfx = ""; - while (1) { - len -= 4; - if (len < 0) - break; - dest += sprint_nip(dest, pfx, option); - pfx = " "; - option += 4; - } } return ret; #endif } /* switch */ + + /* If we are here, try to format any remaining data + * in the option as another, similarly-formatted option + */ option += optlen; len -= optlen; // TODO: it can be a list only if (optflag->flags & OPTION_LIST). // Should we bail out/warn if we see multi-ip option which is // not allowed to be such (for example, DHCP_BROADCAST)? - - if (len <= 0 /* || !(optflag->flags & OPTION_LIST) */) + if (len < optlen /* || !(optflag->flags & OPTION_LIST) */) break; *dest++ = ' '; *dest = '\0'; - } + } /* while */ + return ret; } @@ -378,25 +404,27 @@ static char **fill_envp(struct dhcp_packet *packet) memset(found_opts, 0, sizeof(found_opts)); - /* We need 6 elements for: + /* We need 7 elements for: * "interface=IFACE" * "ip=N.N.N.N" from packet->yiaddr + * "giaddr=IP" from packet->gateway_nip (unless 0) * "siaddr=IP" from packet->siaddr_nip (unless 0) * "boot_file=FILE" from packet->file (unless overloaded) * "sname=SERVER_HOSTNAME" from packet->sname (unless overloaded) * terminating NULL */ - envc = 6; + envc = 7; /* +1 element for each option, +2 for subnet option: */ if (packet) { /* note: do not search for "pad" (0) and "end" (255) options */ +//TODO: change logic to scan packet _once_ for (i = 1; i < 255; i++) { temp = udhcp_get_option(packet, i); if (temp) { if (i == DHCP_OPTION_OVERLOAD) - overload = *temp; + overload |= *temp; else if (i == DHCP_SUBNET) - envc++; /* for mton */ + envc++; /* for $mask */ envc++; /*if (i != DHCP_MESSAGE_TYPE)*/ FOUND_OPTS(i) |= BMASK(i); @@ -405,16 +433,52 @@ static char **fill_envp(struct dhcp_packet *packet) } curr = envp = xzalloc(sizeof(envp[0]) * envc); - *curr = xasprintf("interface=%s", client_config.interface); + *curr = xasprintf("interface=%s", client_data.interface); putenv(*curr++); if (!packet) return envp; + /* Export BOOTP fields. Fields we don't (yet?) export: + * uint8_t op; // always BOOTREPLY + * uint8_t htype; // hardware address type. 1 = 10mb ethernet + * uint8_t hlen; // hardware address length + * uint8_t hops; // used by relay agents only + * uint32_t xid; + * uint16_t secs; // elapsed since client began acquisition/renewal + * uint16_t flags; // only one flag so far: bcast. Never set by server + * uint32_t ciaddr; // client IP (usually == yiaddr. can it be different + * // if during renew server wants to give us different IP?) + * uint8_t chaddr[16]; // link-layer client hardware address (MAC) + */ + /* Most important one: yiaddr as $ip */ *curr = xmalloc(sizeof("ip=255.255.255.255")); sprint_nip(*curr, "ip=", (uint8_t *) &packet->yiaddr); putenv(*curr++); + if (packet->siaddr_nip) { + /* IP address of next server to use in bootstrap */ + *curr = xmalloc(sizeof("siaddr=255.255.255.255")); + sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip); + putenv(*curr++); + } + if (packet->gateway_nip) { + /* IP address of DHCP relay agent */ + *curr = xmalloc(sizeof("giaddr=255.255.255.255")); + sprint_nip(*curr, "giaddr=", (uint8_t *) &packet->gateway_nip); + putenv(*curr++); + } + if (!(overload & FILE_FIELD) && packet->file[0]) { + /* watch out for invalid packets */ + *curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file); + putenv(*curr++); + } + if (!(overload & SNAME_FIELD) && packet->sname[0]) { + /* watch out for invalid packets */ + *curr = xasprintf("sname=%."DHCP_PKT_SNAME_LEN_STR"s", packet->sname); + putenv(*curr++); + } + /* Export known DHCP options */ opt_name = dhcp_option_strings; i = 0; while (*opt_name) { @@ -427,33 +491,18 @@ static char **fill_envp(struct dhcp_packet *packet) temp = udhcp_get_option(packet, code); *curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name); putenv(*curr++); - if (code == DHCP_SUBNET) { + if (code == DHCP_SUBNET && temp[-OPT_DATA + OPT_LEN] == 4) { /* Subnet option: make things like "$ip/$mask" possible */ uint32_t subnet; move_from_unaligned32(subnet, temp); - *curr = xasprintf("mask=%d", mton(subnet)); + *curr = xasprintf("mask=%u", mton(subnet)); putenv(*curr++); } next: opt_name += strlen(opt_name) + 1; i++; } - if (packet->siaddr_nip) { - *curr = xmalloc(sizeof("siaddr=255.255.255.255")); - sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip); - putenv(*curr++); - } - if (!(overload & FILE_FIELD) && packet->file[0]) { - /* watch out for invalid packets */ - *curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file); - putenv(*curr++); - } - if (!(overload & SNAME_FIELD) && packet->sname[0]) { - /* watch out for invalid packets */ - *curr = xasprintf("sname=%."DHCP_PKT_SNAME_LEN_STR"s", packet->sname); - putenv(*curr++); - } - /* Handle unknown options */ + /* Export unknown options */ for (i = 0; i < 256;) { BITMAP bitmap = FOUND_OPTS(i); if (!bitmap) { @@ -475,6 +524,7 @@ static char **fill_envp(struct dhcp_packet *packet) } i++; } + return envp; } @@ -484,14 +534,11 @@ static void udhcp_run_script(struct dhcp_packet *packet, const char *name) char **envp, **curr; char *argv[3]; - if (client_config.script == NULL) - return; - envp = fill_envp(packet); /* call script */ - log1("Executing %s %s", client_config.script, name); - argv[0] = (char*) client_config.script; + log1("executing %s %s", client_data.script, name); + argv[0] = (char*) client_data.script; argv[1] = (char*) name; argv[2] = NULL; spawn_and_wait(argv); @@ -514,27 +561,26 @@ static ALWAYS_INLINE uint32_t random_xid(void) /* Initialize the packet with the proper defaults */ static void init_packet(struct dhcp_packet *packet, char type) { - uint16_t secs; + unsigned secs; /* Fill in: op, htype, hlen, cookie fields; message type option: */ udhcp_init_header(packet, type); packet->xid = random_xid(); - client_config.last_secs = monotonic_sec(); - if (client_config.first_secs == 0) - client_config.first_secs = client_config.last_secs; - secs = client_config.last_secs - client_config.first_secs; - packet->secs = htons(secs); + client_data.last_secs = monotonic_sec(); + if (client_data.first_secs == 0) + client_data.first_secs = client_data.last_secs; + secs = client_data.last_secs - client_data.first_secs; + packet->secs = (secs < 0xffff) ? htons(secs) : 0xffff; - memcpy(packet->chaddr, client_config.client_mac, 6); - if (client_config.clientid) - udhcp_add_binary_option(packet, client_config.clientid); + memcpy(packet->chaddr, client_data.client_mac, 6); + if (client_data.clientid) + udhcp_add_binary_option(packet, client_data.clientid); } static void add_client_options(struct dhcp_packet *packet) { - uint8_t c; int i, end, len; udhcp_add_simple_option(packet, DHCP_MAX_SIZE, htons(IP_UDP_DHCP_SIZE)); @@ -544,13 +590,9 @@ static void add_client_options(struct dhcp_packet *packet) * No bounds checking because it goes towards the head of the packet. */ end = udhcp_end_option(packet->options); len = 0; - for (i = 0; (c = dhcp_optflags[i].code) != 0; i++) { - if (( (dhcp_optflags[i].flags & OPTION_REQ) - && !client_config.no_default_options - ) - || (client_config.opt_mask[c >> 3] & (1 << (c & 7))) - ) { - packet->options[end + OPT_DATA + len] = c; + for (i = 1; i < DHCP_END; i++) { + if (client_data.opt_mask[i >> 3] & (1 << (i & 7))) { + packet->options[end + OPT_DATA + len] = i; len++; } } @@ -560,12 +602,12 @@ static void add_client_options(struct dhcp_packet *packet) packet->options[end + OPT_DATA + len] = DHCP_END; } - if (client_config.vendorclass) - udhcp_add_binary_option(packet, client_config.vendorclass); - if (client_config.hostname) - udhcp_add_binary_option(packet, client_config.hostname); - if (client_config.fqdn) - udhcp_add_binary_option(packet, client_config.fqdn); + if (client_data.vendorclass) + udhcp_add_binary_option(packet, client_data.vendorclass); + if (client_data.hostname) + udhcp_add_binary_option(packet, client_data.hostname); + if (client_data.fqdn) + udhcp_add_binary_option(packet, client_data.fqdn); /* Request broadcast replies if we have no IP addr */ if ((option_mask32 & OPT_B) && packet->ciaddr == 0) @@ -573,16 +615,22 @@ static void add_client_options(struct dhcp_packet *packet) /* Add -x options if any */ { - struct option_set *curr = client_config.options; + struct option_set *curr = client_data.options; while (curr) { udhcp_add_binary_option(packet, curr->data); curr = curr->next; } -// if (client_config.sname) -// strncpy((char*)packet->sname, client_config.sname, sizeof(packet->sname) - 1); -// if (client_config.boot_file) -// strncpy((char*)packet->file, client_config.boot_file, sizeof(packet->file) - 1); +// if (client_data.sname) +// strncpy((char*)packet->sname, client_data.sname, sizeof(packet->sname) - 1); +// if (client_data.boot_file) +// strncpy((char*)packet->file, client_data.boot_file, sizeof(packet->file) - 1); } + + // This will be needed if we remove -V VENDOR_STR in favor of + // -x vendor:VENDOR_STR + //if (!udhcp_find_option(packet.options, DHCP_VENDOR)) + // /* not set, set the default vendor ID */ + // ...add (DHCP_VENDOR, "udhcp "BB_VER) opt... } /* RFC 2131 @@ -603,12 +651,21 @@ static void add_client_options(struct dhcp_packet *packet) * client reverts to using the IP broadcast address. */ -static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet) +static int raw_bcast_from_client_data_ifindex(struct dhcp_packet *packet, uint32_t src_nip) { return udhcp_send_raw_packet(packet, - /*src*/ INADDR_ANY, CLIENT_PORT, + /*src*/ src_nip, CLIENT_PORT, /*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR, - client_config.ifindex); + client_data.ifindex); +} + +static int bcast_or_ucast(struct dhcp_packet *packet, uint32_t ciaddr, uint32_t server) +{ + if (server) + return udhcp_send_kernel_packet(packet, + ciaddr, CLIENT_PORT, + server, SERVER_PORT); + return raw_bcast_from_client_data_ifindex(packet, ciaddr); } /* Broadcast a DHCP discover packet to the network, with an optionally requested IP */ @@ -633,8 +690,8 @@ static NOINLINE int send_discover(uint32_t xid, uint32_t requested) */ add_client_options(&packet); - bb_info_msg("Sending discover..."); - return raw_bcast_from_client_config_ifindex(&packet); + bb_info_msg("sending %s", "discover"); + return raw_bcast_from_client_data_ifindex(&packet, INADDR_ANY); } /* Broadcast a DHCP request message */ @@ -645,7 +702,7 @@ static NOINLINE int send_discover(uint32_t xid, uint32_t requested) static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requested) { struct dhcp_packet packet; - struct in_addr addr; + struct in_addr temp_addr; /* * RFC 2131 4.3.2 DHCPREQUEST message @@ -676,9 +733,9 @@ static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requeste */ add_client_options(&packet); - addr.s_addr = requested; - bb_info_msg("Sending select for %s...", inet_ntoa(addr)); - return raw_bcast_from_client_config_ifindex(&packet); + temp_addr.s_addr = requested; + bb_info_msg("sending select for %s", inet_ntoa(temp_addr)); + return raw_bcast_from_client_data_ifindex(&packet, INADDR_ANY); } /* Unicast or broadcast a DHCP renew message */ @@ -686,6 +743,7 @@ static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requeste static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr) { struct dhcp_packet packet; + struct in_addr temp_addr; /* * RFC 2131 4.3.2 DHCPREQUEST message @@ -716,18 +774,15 @@ static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr) */ add_client_options(&packet); - bb_info_msg("Sending renew..."); - if (server) - return udhcp_send_kernel_packet(&packet, - ciaddr, CLIENT_PORT, - server, SERVER_PORT); - return raw_bcast_from_client_config_ifindex(&packet); + temp_addr.s_addr = server; + bb_info_msg("sending renew to %s", inet_ntoa(temp_addr)); + return bcast_or_ucast(&packet, ciaddr, server); } #if ENABLE_FEATURE_UDHCPC_ARPING /* Broadcast a DHCP decline message */ /* NOINLINE: limit stack usage in caller */ -static NOINLINE int send_decline(uint32_t xid, uint32_t server, uint32_t requested) +static NOINLINE int send_decline(/*uint32_t xid,*/ uint32_t server, uint32_t requested) { struct dhcp_packet packet; @@ -736,24 +791,28 @@ static NOINLINE int send_decline(uint32_t xid, uint32_t server, uint32_t request */ init_packet(&packet, DHCPDECLINE); +#if 0 /* RFC 2131 says DHCPDECLINE's xid is randomly selected by client, * but in case the server is buggy and wants DHCPDECLINE's xid * to match the xid which started entire handshake, * we use the same xid we used in initial DHCPDISCOVER: */ packet.xid = xid; +#endif /* DHCPDECLINE uses "requested ip", not ciaddr, to store offered IP */ udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested); udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server); - bb_info_msg("Sending decline..."); - return raw_bcast_from_client_config_ifindex(&packet); + bb_info_msg("sending %s", "decline"); + return raw_bcast_from_client_data_ifindex(&packet, INADDR_ANY); } #endif /* Unicast a DHCP release message */ -static int send_release(uint32_t server, uint32_t ciaddr) +static +ALWAYS_INLINE /* one caller, help compiler to use this fact */ +int send_release(uint32_t server, uint32_t ciaddr) { struct dhcp_packet packet; @@ -767,8 +826,12 @@ static int send_release(uint32_t server, uint32_t ciaddr) udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server); - bb_info_msg("Sending release..."); - return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT); + bb_info_msg("sending %s", "release"); + /* Note: normally we unicast here since "server" is not zero. + * However, there _are_ people who run "address-less" DHCP servers, + * and reportedly ISC dhcp client and Windows allow that. + */ + return bcast_or_ucast(&packet, ciaddr, server); } /* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */ @@ -778,23 +841,41 @@ static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd) int bytes; struct ip_udp_dhcp_packet packet; uint16_t check; + unsigned char cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))]; + struct iovec iov; + struct msghdr msg; + struct cmsghdr *cmsg; - memset(&packet, 0, sizeof(packet)); - bytes = safe_read(fd, &packet, sizeof(packet)); - if (bytes < 0) { - log1("Packet read error, ignoring"); - /* NB: possible down interface, etc. Caller should pause. */ - return bytes; /* returns -1 */ + /* used to use just safe_read(fd, &packet, sizeof(packet)) + * but we need to check for TP_STATUS_CSUMNOTREADY :( + */ + iov.iov_base = &packet; + iov.iov_len = sizeof(packet); + memset(&msg, 0, sizeof(msg)); + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_control = cmsgbuf; + msg.msg_controllen = sizeof(cmsgbuf); + for (;;) { + bytes = recvmsg(fd, &msg, 0); + if (bytes < 0) { + if (errno == EINTR) + continue; + log1s("packet read error, ignoring"); + /* NB: possible down interface, etc. Caller should pause. */ + return bytes; /* returns -1 */ + } + break; } if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) { - log1("Packet is too short, ignoring"); + log1s("packet is too short, ignoring"); return -2; } if (bytes < ntohs(packet.ip.tot_len)) { /* packet is bigger than sizeof(packet), we did partial read */ - log1("Oversized packet, ignoring"); + log1s("oversized packet, ignoring"); return -2; } @@ -809,7 +890,7 @@ static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd) /* || bytes > (int) sizeof(packet) - can't happen */ || ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip)) ) { - log1("Unrelated/bogus packet, ignoring"); + log1s("unrelated/bogus packet, ignoring"); return -2; } @@ -817,10 +898,24 @@ static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd) check = packet.ip.check; packet.ip.check = 0; if (check != inet_cksum((uint16_t *)&packet.ip, sizeof(packet.ip))) { - log1("Bad IP header checksum, ignoring"); + log1s("bad IP header checksum, ignoring"); return -2; } + for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { + if (cmsg->cmsg_level == SOL_PACKET + && cmsg->cmsg_type == PACKET_AUXDATA + ) { + /* some VMs don't checksum UDP and TCP data + * they send to the same physical machine, + * here we detect this case: + */ + struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg); + if (aux->tp_status & TP_STATUS_CSUMNOTREADY) + goto skip_udp_sum_check; + } + } + /* verify UDP checksum. IP header has to be modified for this */ memset(&packet.ip, 0, offsetof(struct iphdr, protocol)); /* ip.xx fields which are not memset: protocol, check, saddr, daddr */ @@ -828,16 +923,17 @@ static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd) check = packet.udp.check; packet.udp.check = 0; if (check && check != inet_cksum((uint16_t *)&packet, bytes)) { - log1("Packet with bad UDP checksum received, ignoring"); + log1s("packet with bad UDP checksum received, ignoring"); return -2; } + skip_udp_sum_check: if (packet.data.cookie != htonl(DHCP_MAGIC)) { - bb_info_msg("Packet with bad magic, ignoring"); + bb_simple_info_msg("packet with bad magic, ignoring"); return -2; } - log1("Got valid DHCP packet"); + log1("received %s", "a packet"); udhcp_dump_packet(&packet.data); bytes -= sizeof(packet.ip) + sizeof(packet.udp); @@ -848,13 +944,12 @@ static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd) /*** Main ***/ -static int sockfd = -1; - +/* Values for client_data.listen_mode */ #define LISTEN_NONE 0 #define LISTEN_KERNEL 1 #define LISTEN_RAW 2 -static smallint listen_mode; +/* Values for client_data.state */ /* initial state: (re)start DHCP negotiation */ #define INIT_SELECTING 0 /* discover was sent, DHCPOFFER reply received */ @@ -869,145 +964,166 @@ static smallint listen_mode; #define RENEW_REQUESTED 5 /* release, possibly manually requested (SIGUSR2) */ #define RELEASED 6 -static smallint state; static int udhcp_raw_socket(int ifindex) { int fd; struct sockaddr_ll sock; - /* - * Comment: - * - * I've selected not to see LL header, so BPF doesn't see it, too. - * The filter may also pass non-IP and non-ARP packets, but we do - * a more complete check when receiving the message in userspace. - * - * and filter shamelessly stolen from: - * - * http://www.flamewarmaster.de/software/dhcpclient/ - * - * There are a few other interesting ideas on that page (look under - * "Motivation"). Use of netlink events is most interesting. Think - * of various network servers listening for events and reconfiguring. - * That would obsolete sending HUP signals and/or make use of restarts. - * - * Copyright: 2006, 2007 Stefan Rompf . - * License: GPL v2. - * - * TODO: make conditional? - */ - static const struct sock_filter filter_instr[] = { - /* load 9th byte (protocol) */ - BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9), - /* jump to L1 if it is IPPROTO_UDP, else to L4 */ - BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6), - /* L1: load halfword from offset 6 (flags and frag offset) */ - BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6), - /* jump to L4 if any bits in frag offset field are set, else to L2 */ - BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0), - /* L2: skip IP header (load index reg with header len) */ - BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0), - /* load udp destination port from halfword[header_len + 2] */ - BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2), - /* jump to L3 if udp dport is CLIENT_PORT, else to L4 */ - BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1), - /* L3: accept packet */ - BPF_STMT(BPF_RET|BPF_K, 0xffffffff), - /* L4: discard packet */ - BPF_STMT(BPF_RET|BPF_K, 0), - }; - static const struct sock_fprog filter_prog = { - .len = sizeof(filter_instr) / sizeof(filter_instr[0]), - /* casting const away: */ - .filter = (struct sock_filter *) filter_instr, - }; - - log1("Opening raw socket on ifindex %d", ifindex); //log2? + log2("opening raw socket on ifindex %d", ifindex); fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP)); - log1("Got raw socket fd %d", fd); //log2? + /* ^^^^^ + * SOCK_DGRAM: remove link-layer headers on input (SOCK_RAW keeps them) + * ETH_P_IP: want to receive only packets with IPv4 eth type + */ + log3("got raw socket fd %d", fd); + memset(&sock, 0, sizeof(sock)); /* let's be deterministic */ sock.sll_family = AF_PACKET; sock.sll_protocol = htons(ETH_P_IP); sock.sll_ifindex = ifindex; + /*sock.sll_hatype = ARPHRD_???;*/ + /*sock.sll_pkttype = PACKET_???;*/ + /*sock.sll_halen = ???;*/ + /*sock.sll_addr[8] = ???;*/ xbind(fd, (struct sockaddr *) &sock, sizeof(sock)); +#if 0 /* Several users reported breakage when BPF filter is used */ if (CLIENT_PORT == 68) { /* Use only if standard port is in use */ + /* + * I've selected not to see LL header, so BPF doesn't see it, too. + * The filter may also pass non-IP and non-ARP packets, but we do + * a more complete check when receiving the message in userspace. + * + * and filter shamelessly stolen from: + * + * http://www.flamewarmaster.de/software/dhcpclient/ + * + * There are a few other interesting ideas on that page (look under + * "Motivation"). Use of netlink events is most interesting. Think + * of various network servers listening for events and reconfiguring. + * That would obsolete sending HUP signals and/or make use of restarts. + * + * Copyright: 2006, 2007 Stefan Rompf . + * License: GPL v2. + */ + static const struct sock_filter filter_instr[] = { + /* load 9th byte (protocol) */ + BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9), + /* jump to L1 if it is IPPROTO_UDP, else to L4 */ + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6), + /* L1: load halfword from offset 6 (flags and frag offset) */ + BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6), + /* jump to L4 if any bits in frag offset field are set, else to L2 */ + BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0), + /* L2: skip IP header (load index reg with header len) */ + BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0), + /* load udp destination port from halfword[header_len + 2] */ + BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2), + /* jump to L3 if udp dport is CLIENT_PORT, else to L4 */ + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1), + /* L3: accept packet ("accept 0x7fffffff bytes") */ + /* Accepting 0xffffffff works too but kernel 2.6.19 is buggy */ + BPF_STMT(BPF_RET|BPF_K, 0x7fffffff), + /* L4: discard packet ("accept zero bytes") */ + BPF_STMT(BPF_RET|BPF_K, 0), + }; + static const struct sock_fprog filter_prog = { + .len = sizeof(filter_instr) / sizeof(filter_instr[0]), + /* casting const away: */ + .filter = (struct sock_filter *) filter_instr, + }; /* Ignoring error (kernel may lack support for this) */ if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog, sizeof(filter_prog)) >= 0) - log1("Attached filter to raw socket fd %d", fd); // log? + log1("attached filter to raw socket fd"); // log? + } +#endif + + if (setsockopt_1(fd, SOL_PACKET, PACKET_AUXDATA) != 0) { + if (errno != ENOPROTOOPT) + log1s("can't set PACKET_AUXDATA on raw socket"); } - log1("Created raw socket"); + log1s("created raw socket"); return fd; } static void change_listen_mode(int new_mode) { - log1("Entering listen mode: %s", + log1("entering listen mode: %s", new_mode != LISTEN_NONE ? (new_mode == LISTEN_KERNEL ? "kernel" : "raw") : "none" ); - listen_mode = new_mode; - if (sockfd >= 0) { - close(sockfd); - sockfd = -1; + client_data.listen_mode = new_mode; + if (client_data.sockfd >= 0) { + close(client_data.sockfd); + client_data.sockfd = -1; } if (new_mode == LISTEN_KERNEL) - sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface); + client_data.sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_data.interface); else if (new_mode != LISTEN_NONE) - sockfd = udhcp_raw_socket(client_config.ifindex); - /* else LISTEN_NONE: sockfd stays closed */ + client_data.sockfd = udhcp_raw_socket(client_data.ifindex); + /* else LISTEN_NONE: client_data.sockfd stays closed */ } /* Called only on SIGUSR1 */ static void perform_renew(void) { - bb_info_msg("Performing a DHCP renew"); - switch (state) { + bb_simple_info_msg("performing DHCP renew"); + switch (client_data.state) { case BOUND: change_listen_mode(LISTEN_KERNEL); case RENEWING: case REBINDING: - state = RENEW_REQUESTED; + client_data.state = RENEW_REQUESTED; break; case RENEW_REQUESTED: /* impatient are we? fine, square 1 */ udhcp_run_script(NULL, "deconfig"); case REQUESTING: case RELEASED: change_listen_mode(LISTEN_RAW); - state = INIT_SELECTING; + client_data.state = INIT_SELECTING; break; case INIT_SELECTING: break; } } -static void perform_release(uint32_t requested_ip, uint32_t server_addr) +static void perform_release(uint32_t server_addr, uint32_t requested_ip) { char buffer[sizeof("255.255.255.255")]; struct in_addr temp_addr; /* send release packet */ - if (state == BOUND || state == RENEWING || state == REBINDING) { + if (client_data.state == BOUND + || client_data.state == RENEWING + || client_data.state == REBINDING + || client_data.state == RENEW_REQUESTED + ) { temp_addr.s_addr = server_addr; strcpy(buffer, inet_ntoa(temp_addr)); temp_addr.s_addr = requested_ip; - bb_info_msg("Unicasting a release of %s to %s", + bb_info_msg("unicasting a release of %s to %s", inet_ntoa(temp_addr), buffer); send_release(server_addr, requested_ip); /* unicast */ - udhcp_run_script(NULL, "deconfig"); } - bb_info_msg("Entering released state"); + bb_simple_info_msg("entering released state"); +/* + * We can be here on: SIGUSR2, + * or on exit (SIGTERM) and -R "release on quit" is specified. + * Users requested to be notified in all cases, even if not in one + * of the states above. + */ + udhcp_run_script(NULL, "deconfig"); change_listen_mode(LISTEN_NONE); - state = RELEASED; + client_data.state = RELEASED; } static uint8_t* alloc_dhcp_option(int code, const char *str, int extra) @@ -1027,7 +1143,7 @@ static void client_background(void) bb_daemonize(0); logmode &= ~LOGMODE_STDIO; /* rewrite pidfile, as our pid is different now */ - write_pidfile(client_config.pidfile); + write_pidfile(client_data.pidfile); } #endif @@ -1037,95 +1153,57 @@ static void client_background(void) //usage:# define IF_UDHCP_VERBOSE(...) //usage:#endif //usage:#define udhcpc_trivial_usage -//usage: "[-fbnq"IF_UDHCP_VERBOSE("v")"oCRB] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]\n" -//usage: " [-H HOSTNAME] [-V VENDOR] [-x OPT:VAL]... [-O OPT]..." IF_FEATURE_UDHCP_PORT(" [-P N]") +//usage: "[-fbq"IF_UDHCP_VERBOSE("v")"RB]"IF_FEATURE_UDHCPC_ARPING(" [-a[MSEC]]")" [-t N] [-T SEC] [-A SEC/-n]\n" +//usage: " [-i IFACE]"IF_FEATURE_UDHCP_PORT(" [-P PORT]")" [-s PROG] [-p PIDFILE]\n" +//usage: " [-oC] [-r IP] [-V VENDOR] [-F NAME] [-x OPT:VAL]... [-O OPT]..." //usage:#define udhcpc_full_usage "\n" -//usage: IF_LONG_OPTS( -//usage: "\n -i,--interface IFACE Interface to use (default eth0)" -//usage: "\n -p,--pidfile FILE Create pidfile" -//usage: "\n -s,--script PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")" -//usage: "\n -B,--broadcast Request broadcast replies" -//usage: "\n -t,--retries N Send up to N discover packets" -//usage: "\n -T,--timeout N Pause between packets (default 3 seconds)" -//usage: "\n -A,--tryagain N Wait N seconds after failure (default 20)" -//usage: "\n -f,--foreground Run in foreground" -//usage: USE_FOR_MMU( -//usage: "\n -b,--background Background if lease is not obtained" -//usage: ) -//usage: "\n -n,--now Exit if lease is not obtained" -//usage: "\n -q,--quit Exit after obtaining lease" -//usage: "\n -R,--release Release IP on exit" -//usage: "\n -S,--syslog Log to syslog too" +//usage: "\n -i IFACE Interface to use (default eth0)" //usage: IF_FEATURE_UDHCP_PORT( -//usage: "\n -P,--client-port N Use port N (default 68)" +//usage: "\n -P PORT Use PORT (default 68)" //usage: ) -//usage: IF_FEATURE_UDHCPC_ARPING( -//usage: "\n -a,--arping Use arping to validate offered address" -//usage: ) -//usage: "\n -O,--request-option OPT Request option OPT from server (cumulative)" -//usage: "\n -o,--no-default-options Don't request any options (unless -O is given)" -//usage: "\n -r,--request IP Request this IP address" -//usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)" -//usage: "\n Examples of string, numeric, and hex byte opts:" -//usage: "\n -x hostname:bbox - option 12" -//usage: "\n -x lease:3600 - option 51 (lease time)" -//usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)" -//usage: "\n -F,--fqdn NAME Ask server to update DNS mapping for NAME" -//usage: "\n -H,-h,--hostname NAME Send NAME as client hostname (default none)" -//usage: "\n -V,--vendorclass VENDOR Vendor identifier (default 'udhcp VERSION')" -//usage: "\n -C,--clientid-none Don't send MAC as client identifier" -//usage: IF_UDHCP_VERBOSE( -//usage: "\n -v Verbose" -//usage: ) -//usage: ) -//usage: IF_NOT_LONG_OPTS( -//usage: "\n -i IFACE Interface to use (default eth0)" -//usage: "\n -p FILE Create pidfile" //usage: "\n -s PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")" +//usage: "\n -p FILE Create pidfile" //usage: "\n -B Request broadcast replies" -//usage: "\n -t N Send up to N discover packets" -//usage: "\n -T N Pause between packets (default 3 seconds)" -//usage: "\n -A N Wait N seconds (default 20) after failure" -//usage: "\n -f Run in foreground" +//usage: "\n -t N Send up to N discover packets (default 3)" +//usage: "\n -T SEC Pause between packets (default 3)" +//usage: "\n -A SEC Wait if lease is not obtained (default 20)" //usage: USE_FOR_MMU( //usage: "\n -b Background if lease is not obtained" //usage: ) //usage: "\n -n Exit if lease is not obtained" //usage: "\n -q Exit after obtaining lease" //usage: "\n -R Release IP on exit" +//usage: "\n -f Run in foreground" //usage: "\n -S Log to syslog too" -//usage: IF_FEATURE_UDHCP_PORT( -//usage: "\n -P N Use port N (default 68)" -//usage: ) //usage: IF_FEATURE_UDHCPC_ARPING( -//usage: "\n -a Use arping to validate offered address" +//usage: "\n -a[MSEC] Validate offered address with ARP ping" //usage: ) -//usage: "\n -O OPT Request option OPT from server (cumulative)" -//usage: "\n -o Don't request any options (unless -O is given)" //usage: "\n -r IP Request this IP address" +//usage: "\n -o Don't request any options (unless -O is given)" +//usage: "\n -O OPT Request option OPT from server (cumulative)" //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)" //usage: "\n Examples of string, numeric, and hex byte opts:" //usage: "\n -x hostname:bbox - option 12" //usage: "\n -x lease:3600 - option 51 (lease time)" //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)" +//usage: "\n -x 14:'\"dumpfile\"' - option 14 (shell-quoted)" //usage: "\n -F NAME Ask server to update DNS mapping for NAME" -//usage: "\n -H,-h NAME Send NAME as client hostname (default none)" //usage: "\n -V VENDOR Vendor identifier (default 'udhcp VERSION')" //usage: "\n -C Don't send MAC as client identifier" //usage: IF_UDHCP_VERBOSE( //usage: "\n -v Verbose" //usage: ) -//usage: ) //usage: "\nSignals:" -//usage: "\n USR1 Renew current lease" -//usage: "\n USR2 Release current lease" +//usage: "\n USR1 Renew lease" +//usage: "\n USR2 Release lease" int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int udhcpc_main(int argc UNUSED_PARAM, char **argv) { - uint8_t *temp, *message; + uint8_t *message; const char *str_V, *str_h, *str_F, *str_r; + IF_FEATURE_UDHCPC_ARPING(const char *str_a = "2000";) IF_FEATURE_UDHCP_PORT(char *str_P;) void *clientid_mac_ptr; llist_t *list_O = NULL; @@ -1135,48 +1213,57 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) int discover_retries = 3; uint32_t server_addr = server_addr; /* for compiler */ uint32_t requested_ip = 0; - uint32_t xid = 0; - uint32_t lease_seconds = 0; /* can be given as 32-bit quantity */ + uint32_t xid = xid; /* for compiler */ int packet_num; int timeout; /* must be signed */ unsigned already_waited_sec; unsigned opt; - int max_fd; + IF_FEATURE_UDHCPC_ARPING(unsigned arpping_ms;) int retval; - struct timeval tv; - struct dhcp_packet packet; - fd_set rfds; + + setup_common_bufsiz(); /* Default options */ IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;) IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;) - client_config.interface = "eth0"; - client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT; + client_data.interface = "eth0"; + client_data.script = CONFIG_UDHCPC_DEFAULT_SCRIPT; + client_data.sockfd = -1; str_V = "udhcp "BB_VER; + /* Make sure fd 0,1,2 are open */ + /* Set up the signal pipe on fds 3,4 - must be before openlog() */ + udhcp_sp_setup(); + /* Parse command line */ - /* O,x: list; -T,-t,-A take numeric param */ - opt_complementary = "O::x::T+:t+:A+" IF_UDHCP_VERBOSE(":vv") ; - IF_LONG_OPTS(applet_long_options = udhcpc_longopts;) - opt = getopt32(argv, "CV:H:h:F:i:np:qRr:s:T:t:SA:O:ox:fB" + opt = getopt32long(argv, "^" + /* O,x: list; -T,-t,-A take numeric param */ + "CV:H:h:F:i:np:qRr:s:T:+t:+SA:+O:*ox:*fB" USE_FOR_MMU("b") - IF_FEATURE_UDHCPC_ARPING("a") + IF_FEATURE_UDHCPC_ARPING("a::") IF_FEATURE_UDHCP_PORT("P:") "v" + "\0" IF_UDHCP_VERBOSE("vv") /* -v is a counter */ + , udhcpc_longopts , &str_V, &str_h, &str_h, &str_F - , &client_config.interface, &client_config.pidfile, &str_r /* i,p */ - , &client_config.script /* s */ + , &client_data.interface, &client_data.pidfile /* i,p */ + , &str_r /* r */ + , &client_data.script /* s */ , &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */ , &list_O , &list_x + IF_FEATURE_UDHCPC_ARPING(, &str_a) IF_FEATURE_UDHCP_PORT(, &str_P) IF_UDHCP_VERBOSE(, &dhcp_verbose) - ); - if (opt & (OPT_h|OPT_H)) - client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0); + ); + if (opt & (OPT_h|OPT_H)) { + //msg added 2011-11 + bb_simple_error_msg("option -h NAME is deprecated, use -x hostname:NAME"); + client_data.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0); + } if (opt & OPT_F) { /* FQDN option format: [0x51][len][flags][0][0] */ - client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3); + client_data.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3); /* Flag bits: 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 regardless @@ -1185,9 +1272,9 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) * N: 1 = Client requests server to not update DNS (S must be 0 then) * Two [0] bytes which follow are deprecated and must be 0. */ - client_config.fqdn[OPT_DATA + 0] = 0x1; - /*client_config.fqdn[OPT_DATA + 1] = 0; - xzalloc did it */ - /*client_config.fqdn[OPT_DATA + 2] = 0; */ + client_data.fqdn[OPT_DATA + 0] = 0x1; + /*client_data.fqdn[OPT_DATA + 1] = 0; - xzalloc did it */ + /*client_data.fqdn[OPT_DATA + 2] = 0; */ } if (opt & OPT_r) requested_ip = inet_addr(str_r); @@ -1197,45 +1284,59 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) SERVER_PORT = CLIENT_PORT - 1; } #endif - if (opt & OPT_o) - client_config.no_default_options = 1; + IF_FEATURE_UDHCPC_ARPING(arpping_ms = xatou(str_a);) while (list_O) { char *optstr = llist_pop(&list_O); unsigned n = bb_strtou(optstr, NULL, 0); if (errno || n > 254) { - n = udhcp_option_idx(optstr); + n = udhcp_option_idx(optstr, dhcp_option_strings); n = dhcp_optflags[n].code; } - client_config.opt_mask[n >> 3] |= 1 << (n & 7); + client_data.opt_mask[n >> 3] |= 1 << (n & 7); + } + if (!(opt & OPT_o)) { + unsigned i, n; + for (i = 0; (n = dhcp_optflags[i].code) != 0; i++) { + if (dhcp_optflags[i].flags & OPTION_REQ) { + client_data.opt_mask[n >> 3] |= 1 << (n & 7); + } + } } while (list_x) { - char *optstr = llist_pop(&list_x); - char *colon = strchr(optstr, ':'); - if (colon) - *colon = ' '; - /* now it looks similar to udhcpd's config file line: - * "optname optval", using the common routine: */ - udhcp_str2optset(optstr, &client_config.options); + char *optstr = xstrdup(llist_pop(&list_x)); + udhcp_str2optset(optstr, &client_data.options, + dhcp_optflags, dhcp_option_strings, + /*dhcpv6:*/ 0 + ); + free(optstr); } - if (udhcp_read_interface(client_config.interface, - &client_config.ifindex, + if (udhcp_read_interface(client_data.interface, + &client_data.ifindex, NULL, - client_config.client_mac) + client_data.client_mac) ) { return 1; } clientid_mac_ptr = NULL; - if (!(opt & OPT_C) && !udhcp_find_option(client_config.options, DHCP_CLIENT_ID)) { + if (!(opt & OPT_C) && !udhcp_find_option(client_data.options, DHCP_CLIENT_ID)) { /* not suppressed and not set, set the default client ID */ - client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7); - client_config.clientid[OPT_DATA] = 1; /* type: ethernet */ - clientid_mac_ptr = client_config.clientid + OPT_DATA+1; - memcpy(clientid_mac_ptr, client_config.client_mac, 6); + client_data.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7); + client_data.clientid[OPT_DATA] = 1; /* type: ethernet */ + clientid_mac_ptr = client_data.clientid + OPT_DATA+1; + memcpy(clientid_mac_ptr, client_data.client_mac, 6); } - if (str_V[0] != '\0') - client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0); + if (str_V[0] != '\0') { + // can drop -V, str_V, client_data.vendorclass, + // but need to add "vendor" to the list of recognized + // string opts for this to work; + // and need to tweak add_client_options() too... + // ...so the question is, should we? + //bb_error_msg("option -V VENDOR is deprecated, use -x vendor:VENDOR"); + client_data.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0); + } + #if !BB_MMU /* on NOMMU reexec (i.e., background) early */ if (!(opt & OPT_f)) { @@ -1248,20 +1349,14 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) logmode |= LOGMODE_SYSLOG; } - /* Make sure fd 0,1,2 are open */ - bb_sanitize_stdio(); - /* Equivalent of doing a fflush after every \n */ - setlinebuf(stdout); /* Create pidfile */ - write_pidfile(client_config.pidfile); + write_pidfile(client_data.pidfile); /* Goes to stdout (unless NOMMU) and possibly syslog */ - bb_info_msg("%s (v"BB_VER") started", applet_name); - /* Set up the signal pipe */ - udhcp_sp_setup(); + bb_simple_info_msg("started, v"BB_VER); /* We want random_xid to be random... */ srand(monotonic_us()); - state = INIT_SELECTING; + client_data.state = INIT_SELECTING; udhcp_run_script(NULL, "deconfig"); change_listen_mode(LISTEN_RAW); packet_num = 0; @@ -1273,36 +1368,38 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) * "continue" statements in code below jump to the top of the loop. */ for (;;) { + int tv; + struct pollfd pfds[2]; + struct dhcp_packet packet; /* silence "uninitialized!" warning */ unsigned timestamp_before_wait = timestamp_before_wait; - //bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode); + //bb_error_msg("sockfd:%d, listen_mode:%d", client_data.sockfd, client_data.listen_mode); /* Was opening raw or udp socket here - * if (listen_mode != LISTEN_NONE && sockfd < 0), + * if (client_data.listen_mode != LISTEN_NONE && client_data.sockfd < 0), * but on fast network renew responses return faster * than we open sockets. Thus this code is moved * to change_listen_mode(). Thus we open listen socket * BEFORE we send renew request (see "case BOUND:"). */ - max_fd = udhcp_sp_fd_set(&rfds, sockfd); + udhcp_sp_fd_set(pfds, client_data.sockfd); - tv.tv_sec = timeout - already_waited_sec; - tv.tv_usec = 0; + tv = timeout - already_waited_sec; retval = 0; /* If we already timed out, fall through with retval = 0, else... */ - if ((int)tv.tv_sec > 0) { + if (tv > 0) { + log1("waiting %u seconds", tv); timestamp_before_wait = (unsigned)monotonic_sec(); - log1("Waiting on select..."); - retval = select(max_fd + 1, &rfds, NULL, NULL, &tv); + retval = poll(pfds, 2, tv < INT_MAX/1000 ? tv * 1000 : INT_MAX); if (retval < 0) { /* EINTR? A signal was caught, don't panic */ if (errno == EINTR) { already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait; continue; } - /* Else: an error occured, panic! */ - bb_perror_msg_and_die("select"); + /* Else: an error occurred, panic! */ + bb_simple_perror_msg_and_die("poll"); } } @@ -1315,22 +1412,22 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) * or if the status of the bridge changed). * Refresh ifindex and client_mac: */ - if (udhcp_read_interface(client_config.interface, - &client_config.ifindex, + if (udhcp_read_interface(client_data.interface, + &client_data.ifindex, NULL, - client_config.client_mac) + client_data.client_mac) ) { - return 1; /* iface is gone? */ + goto ret0; /* iface is gone? */ } if (clientid_mac_ptr) - memcpy(clientid_mac_ptr, client_config.client_mac, 6); + memcpy(clientid_mac_ptr, client_data.client_mac, 6); /* We will restart the wait in any case */ already_waited_sec = 0; - switch (state) { + switch (client_data.state) { case INIT_SELECTING: - if (packet_num < discover_retries) { + if (!discover_retries || packet_num < discover_retries) { if (packet_num == 0) xid = random_xid(); /* broadcast */ @@ -1343,14 +1440,20 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) udhcp_run_script(NULL, "leasefail"); #if BB_MMU /* -b is not supported on NOMMU */ if (opt & OPT_b) { /* background if no lease */ - bb_info_msg("No lease, forking to background"); + bb_simple_info_msg("no lease, forking to background"); client_background(); /* do not background again! */ - opt = ((opt & ~OPT_b) | OPT_f); + opt = ((opt & ~(OPT_b|OPT_n)) | OPT_f); + /* ^^^ also disables -n (-b takes priority over -n): + * ifup's default udhcpc options are -R -n, + * and users want to be able to add -b + * (in a config file) to make it background + * _and not exit_. + */ } else #endif if (opt & OPT_n) { /* abort if no lease */ - bb_info_msg("No lease, failing"); + bb_simple_info_msg("no lease, failing"); retval = 1; goto ret; } @@ -1359,7 +1462,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) packet_num = 0; continue; case REQUESTING: - if (packet_num < discover_retries) { + if (packet_num < 3) { /* send broadcast select packet */ send_select(xid, server_addr, requested_ip); timeout = discover_timeout; @@ -1371,19 +1474,19 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) * were seen in the wild. Treat them similarly * to "no response to discover" case */ change_listen_mode(LISTEN_RAW); - state = INIT_SELECTING; + client_data.state = INIT_SELECTING; goto leasefail; case BOUND: /* 1/2 lease passed, enter renewing state */ - state = RENEWING; - client_config.first_secs = 0; /* make secs field count from 0 */ + client_data.state = RENEWING; + client_data.first_secs = 0; /* make secs field count from 0 */ change_listen_mode(LISTEN_KERNEL); - log1("Entering renew state"); + log1s("entering renew state"); /* fall right through */ case RENEW_REQUESTED: /* manual (SIGUSR1) renew */ case_RENEW_REQUESTED: case RENEWING: - if (timeout > 60) { + if (timeout >= 60) { /* send an unicast renew request */ /* Sometimes observed to fail (EADDRNOTAVAIL) to bind * a new UDP socket for sending inside send_renew. @@ -1393,13 +1496,26 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) * Anyway, it does recover by eventually failing through * into INIT_SELECTING state. */ - send_renew(xid, server_addr, requested_ip); - timeout >>= 1; - continue; + if (send_renew(xid, server_addr, requested_ip) >= 0) { + timeout >>= 1; +//TODO: the timeout to receive an answer for our renew should not be selected +//with "timeout = lease_seconds / 2; ...; timeout = timeout / 2": it is often huge. +//Waiting e.g. 4*3600 seconds for a reply does not make sense +//(if reply isn't coming, we keep an open socket for hours), +//it should be something like 10 seconds. +//Also, it's probably best to try sending renew in kernel mode a few (3-5) times +//and fall back to raw mode if it does not work. + continue; + } + /* else: error sending. + * example: ENETUNREACH seen with server + * which gave us bogus server ID 1.1.1.1 + * which wasn't reachable (and probably did not exist). + */ } - /* Timed out, enter rebinding state */ - log1("Entering rebinding state"); - state = REBINDING; + /* Timed out or error, enter rebinding state */ + log1s("entering rebinding state"); + client_data.state = REBINDING; /* fall right through */ case REBINDING: /* Switch to bcast receive */ @@ -1413,10 +1529,10 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) continue; } /* Timed out, enter init state */ - bb_info_msg("Lease lost, entering init state"); + bb_simple_info_msg("lease lost, entering init state"); udhcp_run_script(NULL, "deconfig"); - state = INIT_SELECTING; - client_config.first_secs = 0; /* make secs field count from 0 */ + client_data.state = INIT_SELECTING; + client_data.first_secs = 0; /* make secs field count from 0 */ /*timeout = 0; - already is */ packet_num = 0; continue; @@ -1425,18 +1541,17 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) /* yah, I know, *you* say it would never happen */ timeout = INT_MAX; continue; /* back to main loop */ - } /* if select timed out */ + } /* if poll timed out */ - /* select() didn't timeout, something happened */ + /* poll() didn't timeout, something happened */ /* Is it a signal? */ - /* note: udhcp_sp_read checks FD_ISSET before reading */ - switch (udhcp_sp_read(&rfds)) { + switch (udhcp_sp_read()) { case SIGUSR1: - client_config.first_secs = 0; /* make secs field count from 0 */ + client_data.first_secs = 0; /* make secs field count from 0 */ already_waited_sec = 0; perform_renew(); - if (state == RENEW_REQUESTED) { + if (client_data.state == RENEW_REQUESTED) { /* We might be either on the same network * (in which case renew might work), * or we might be on a completely different one @@ -1444,11 +1559,9 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) * For the second case, must make sure timeout * is not too big, or else we can send * futile renew requests for hours. - * (Ab)use -A TIMEOUT value (usually 20 sec) - * as a cap on the timeout. */ - if (timeout > tryagain_timeout) - timeout = tryagain_timeout; + if (timeout > 60) + timeout = 60; goto case_RENEW_REQUESTED; } /* Start things over */ @@ -1457,33 +1570,31 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) timeout = 0; continue; case SIGUSR2: - perform_release(requested_ip, server_addr); + perform_release(server_addr, requested_ip); timeout = INT_MAX; continue; case SIGTERM: - bb_info_msg("Received SIGTERM"); - if (opt & OPT_R) /* release on quit */ - perform_release(requested_ip, server_addr); + bb_info_msg("received %s", "SIGTERM"); goto ret0; } /* Is it a packet? */ - if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds)) + if (!pfds[1].revents) continue; /* no */ { int len; /* A packet is ready, read it */ - if (listen_mode == LISTEN_KERNEL) - len = udhcp_recv_kernel_packet(&packet, sockfd); + if (client_data.listen_mode == LISTEN_KERNEL) + len = udhcp_recv_kernel_packet(&packet, client_data.sockfd); else - len = udhcp_recv_raw_packet(&packet, sockfd); + len = udhcp_recv_raw_packet(&packet, client_data.sockfd); if (len == -1) { /* Error is severe, reopen socket */ - bb_info_msg("Read error: %s, reopening socket", strerror(errno)); + bb_error_msg("read error: "STRERROR_FMT", reopening socket" STRERROR_ERRNO); sleep(discover_timeout); /* 3 seconds by default */ - change_listen_mode(listen_mode); /* just close and reopen */ + change_listen_mode(client_data.listen_mode); /* just close and reopen */ } /* If this packet will turn out to be unrelated/bogus, * we will go back and wait for next one. @@ -1501,37 +1612,62 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) /* Ignore packets that aren't for us */ if (packet.hlen != 6 - || memcmp(packet.chaddr, client_config.client_mac, 6) != 0 + || memcmp(packet.chaddr, client_data.client_mac, 6) != 0 ) { //FIXME: need to also check that last 10 bytes are zero - log1("chaddr does not match, ignoring packet"); // log2? + log1("chaddr does not match%s", ", ignoring packet"); // log2? continue; } message = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE); if (message == NULL) { - bb_error_msg("no message type option, ignoring packet"); + bb_info_msg("no message type option%s", ", ignoring packet"); continue; } - switch (state) { + switch (client_data.state) { case INIT_SELECTING: - /* Must be a DHCPOFFER to one of our xid's */ + /* Must be a DHCPOFFER */ if (*message == DHCPOFFER) { - /* TODO: why we don't just fetch server's IP from IP header? */ - temp = udhcp_get_option(&packet, DHCP_SERVER_ID); + uint8_t *temp; + +/* What exactly is server's IP? There are several values. + * Example DHCP offer captured with tchdump: + * + * 10.34.25.254:67 > 10.34.25.202:68 // IP header's src + * BOOTP fields: + * Your-IP 10.34.25.202 + * Server-IP 10.34.32.125 // "next server" IP + * Gateway-IP 10.34.25.254 // relay's address (if DHCP relays are in use) + * DHCP options: + * DHCP-Message Option 53, length 1: Offer + * Server-ID Option 54, length 4: 10.34.255.7 // "server ID" + * Default-Gateway Option 3, length 4: 10.34.25.254 // router + * + * We think that real server IP (one to use in renew/release) + * is one in Server-ID option. But I am not 100% sure. + * IP header's src and Gateway-IP (same in this example) + * might work too. + * "Next server" and router are definitely wrong ones to use, though... + */ +/* We used to ignore packets without DHCP_SERVER_ID. + * I've got user reports from people who run "address-less" servers. + * They either supply DHCP_SERVER_ID of 0.0.0.0 or don't supply it at all. + * They say ISC DHCP client supports this case. + */ + server_addr = 0; + temp = udhcp_get_option32(&packet, DHCP_SERVER_ID); if (!temp) { - bb_error_msg("no server ID, ignoring packet"); - continue; - /* still selecting - this server looks bad */ + bb_simple_info_msg("no server ID, using 0.0.0.0"); + } else { + /* it IS unaligned sometimes, don't "optimize" */ + move_from_unaligned32(server_addr, temp); } - /* it IS unaligned sometimes, don't "optimize" */ - move_from_unaligned32(server_addr, temp); /*xid = packet.xid; - already is */ requested_ip = packet.yiaddr; /* enter requesting state */ - state = REQUESTING; + client_data.state = REQUESTING; timeout = 0; packet_num = 0; already_waited_sec = 0; @@ -1542,17 +1678,27 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) case RENEW_REQUESTED: case REBINDING: if (*message == DHCPACK) { - temp = udhcp_get_option(&packet, DHCP_LEASE_TIME); + unsigned start; + uint32_t lease_seconds; + struct in_addr temp_addr; + uint8_t *temp; + + temp = udhcp_get_option32(&packet, DHCP_LEASE_TIME); if (!temp) { - bb_error_msg("no lease time with ACK, using 1 hour lease"); + bb_simple_info_msg("no lease time with ACK, using 1 hour lease"); lease_seconds = 60 * 60; } else { /* it IS unaligned sometimes, don't "optimize" */ move_from_unaligned32(lease_seconds, temp); lease_seconds = ntohl(lease_seconds); - lease_seconds &= 0x0fffffff; /* paranoia: must not be prone to overflows */ - if (lease_seconds < 10) /* and not too small */ - lease_seconds = 10; + /* paranoia: must not be too small and not prone to overflows */ + /* timeout > 60 - ensures at least one unicast renew attempt */ + if (lease_seconds < 2 * 61) + lease_seconds = 2 * 61; + //if (lease_seconds > 0x7fffffff) + // lease_seconds = 0x7fffffff; + //^^^not necessary since "timeout = lease_seconds / 2" + //does not overflow even for 0xffffffff. } #if ENABLE_FEATURE_UDHCPC_ARPING if (opt & OPT_a) { @@ -1568,18 +1714,19 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) if (!arpping(packet.yiaddr, NULL, (uint32_t) 0, - client_config.client_mac, - client_config.interface) + client_data.client_mac, + client_data.interface, + arpping_ms) ) { - bb_info_msg("Offered address is in use " + bb_simple_info_msg("offered address is in use " "(got ARP reply), declining"); - send_decline(xid, server_addr, packet.yiaddr); + send_decline(/*xid,*/ server_addr, packet.yiaddr); - if (state != REQUESTING) + if (client_data.state != REQUESTING) udhcp_run_script(NULL, "deconfig"); change_listen_mode(LISTEN_RAW); - state = INIT_SELECTING; - client_config.first_secs = 0; /* make secs field count from 0 */ + client_data.state = INIT_SELECTING; + client_data.first_secs = 0; /* make secs field count from 0 */ requested_ip = 0; timeout = tryagain_timeout; packet_num = 0; @@ -1589,21 +1736,23 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) } #endif /* enter bound state */ + temp_addr.s_addr = packet.yiaddr; + bb_info_msg("lease of %s obtained, lease time %u", + inet_ntoa(temp_addr), (unsigned)lease_seconds); + requested_ip = packet.yiaddr; + + start = monotonic_sec(); + udhcp_run_script(&packet, client_data.state == REQUESTING ? "bound" : "renew"); + already_waited_sec = (unsigned)monotonic_sec() - start; timeout = lease_seconds / 2; - { - struct in_addr temp_addr; - temp_addr.s_addr = packet.yiaddr; - bb_info_msg("Lease of %s obtained, lease time %u", - inet_ntoa(temp_addr), (unsigned)lease_seconds); + if ((unsigned)timeout < already_waited_sec) { + /* Something went wrong. Back to discover state */ + timeout = already_waited_sec = 0; } - requested_ip = packet.yiaddr; - udhcp_run_script(&packet, state == REQUESTING ? "bound" : "renew"); - state = BOUND; + client_data.state = BOUND; change_listen_mode(LISTEN_NONE); if (opt & OPT_q) { /* quit after lease */ - if (opt & OPT_R) /* release on quit */ - perform_release(requested_ip, server_addr); goto ret0; } /* future renew failures should not exit (JM) */ @@ -1615,19 +1764,40 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) opt = ((opt & ~OPT_b) | OPT_f); } #endif - already_waited_sec = 0; + /* make future renew packets use different xid */ + /* xid = random_xid(); ...but why bother? */ + continue; /* back to main loop */ } if (*message == DHCPNAK) { + /* If network has more than one DHCP server, + * "wrong" server can reply first, with a NAK. + * Do not interpret it as a NAK from "our" server. + */ + if (server_addr != 0) { + uint32_t svid; + uint8_t *temp; + + temp = udhcp_get_option32(&packet, DHCP_SERVER_ID); + if (!temp) { + non_matching_svid: + log1("received DHCP NAK with wrong" + " server ID%s", ", ignoring packet"); + continue; + } + move_from_unaligned32(svid, temp); + if (svid != server_addr) + goto non_matching_svid; + } /* return to init state */ - bb_info_msg("Received DHCP NAK"); + bb_info_msg("received %s", "DHCP NAK"); udhcp_run_script(&packet, "nak"); - if (state != REQUESTING) + if (client_data.state != REQUESTING) udhcp_run_script(NULL, "deconfig"); change_listen_mode(LISTEN_RAW); sleep(3); /* avoid excessive network traffic */ - state = INIT_SELECTING; - client_config.first_secs = 0; /* make secs field count from 0 */ + client_data.state = INIT_SELECTING; + client_data.first_secs = 0; /* make secs field count from 0 */ requested_ip = 0; timeout = 0; packet_num = 0; @@ -1641,9 +1811,11 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) } /* for (;;) - main loop ends */ ret0: + if (opt & OPT_R) /* release on quit */ + perform_release(server_addr, requested_ip); retval = 0; ret: - /*if (client_config.pidfile) - remove_pidfile has its own check */ - remove_pidfile(client_config.pidfile); + /*if (client_data.pidfile) - remove_pidfile has its own check */ + remove_pidfile(client_data.pidfile); return retval; }