diff options
Diffstat (limited to 'client/dhclient.c')
| -rw-r--r-- | client/dhclient.c | 205 |
1 files changed, 177 insertions, 28 deletions
diff --git a/client/dhclient.c b/client/dhclient.c index 57d53adc..46dc3a71 100644 --- a/client/dhclient.c +++ b/client/dhclient.c @@ -3,7 +3,7 @@ DHCP Client. */ /* - * Copyright (c) 2004-2021 by Internet Systems Consortium, Inc. ("ISC") + * Copyright (c) 2004-2022 by Internet Systems Consortium, Inc. ("ISC") * Copyright (c) 1995-2003 by Internet Software Consortium * * This Source Code Form is subject to the terms of the Mozilla Public @@ -19,8 +19,8 @@ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * * Internet Systems Consortium, Inc. - * 950 Charter Street - * Redwood City, CA 94063 + * PO Box 360 + * Newmarket, NH 03857 USA * <info@isc.org> * https://www.isc.org/ * @@ -77,14 +77,15 @@ int decline_wait_time = 10; /* Default to 10 secs per, RFC 2131, 3.1.5 */ #define ASSERT_STATE(state_is, state_shouldbe) {} #ifndef UNIT_TEST -static const char copyright[] = "Copyright 2004-2021 Internet Systems Consortium."; +static const char copyright[] = "Copyright 2004-2022 Internet Systems Consortium."; static const char arr [] = "All rights reserved."; static const char message [] = "Internet Systems Consortium DHCP Client"; static const char url [] = "For info, please visit https://www.isc.org/software/dhcp/"; #endif /* UNIT_TEST */ -u_int16_t local_port = 0; -u_int16_t remote_port = 0; +extern u_int16_t local_port; +extern u_int16_t remote_port; + #if defined(DHCPv6) && defined(DHCP4o6) int dhcp4o6_state = -1; /* -1 = stopped, 0 = polling, 1 = started */ #endif @@ -136,10 +137,10 @@ static void dhclient_ddns_cb_free(dhcp_ddns_cb_t *ddns_cb, * the description of the command line. The arguments provide * a way for the caller to request more specific information about * the error be printed as well. Mostly this will be that some - * comamnd doesn't include its argument. + * command doesn't include its argument. * * \param sfmt - The basic string and format for the specific error - * \param sarg - Generally the offending argument from the comamnd line. + * \param sarg - Generally the offending argument from the command line. * * \return Nothing */ @@ -566,7 +567,7 @@ main(int argc, char **argv) { } else if (argv[i][0] == '-') { usage("Unknown command: %s", argv[i]); } else if (interfaces_requested < 0) { - usage("No interfaces comamnd -n and " + usage("No interfaces command -n and " " requested interface %s", argv[i]); } else { struct interface_info *tmp = NULL; @@ -828,21 +829,36 @@ main(int argc, char **argv) { ? DISCOVER_REQUESTED : DISCOVER_RUNNING); - /* Make up a seed for the random number generator from current - time plus the sum of the last four bytes of each - interface's hardware address interpreted as an integer. - Not much entropy, but we're booting, so we're not likely to - find anything better. */ + /* PLEASE PREFER the random device: not all systems use random + * process identifiers so the alternative can be predictable. */ seed = 0; - for (ip = interfaces; ip; ip = ip->next) { - int junk; - memcpy(&junk, - &ip->hw_address.hbuf[ip->hw_address.hlen - - sizeof seed], sizeof seed); - seed += junk; + size_t nrnd = 0; +#ifdef ISC_PATH_RANDOMDEV + FILE *frnd = fopen(ISC_PATH_RANDOMDEV, "r"); + if (frnd) { + nrnd = fread(&seed, sizeof(seed), 1, frnd); + fclose(frnd); } - srandom(seed + cur_time + (unsigned)getpid()); +#endif + /* Please leave the compiler to emit a warning about a constant + * condition in the if test. */ + if (!nrnd) { + /* Make up a seed for the random number generator from current + time plus the sum of the last four bytes of each + interface's hardware address interpreted as an integer. + Not much entropy, but we're booting, so we're not likely to + find anything better. */ + for (ip = interfaces; ip; ip = ip->next) { + int junk; + memcpy(&junk, + &ip->hw_address.hbuf[ip->hw_address.hlen - + sizeof seed], sizeof seed); + seed += junk; + } + seed += cur_time + (unsigned)getpid(); + } + srandom(seed); /* * Establish a default DUID. We always do so for v6 and @@ -1241,6 +1257,105 @@ void state_init (cpp) send_discover (client); } +/* check_v6only is called by dhcpoffer and dhcpack. It checks if a + * requested v6-only-preferred option is present and returned the + * V6ONLY_WAIT delay to suspend DHCPv4. */ + +uint32_t check_v6only(packet, client) + struct packet *packet; + struct client_state *client; +{ + int i; + struct option **req; + isc_boolean_t found = ISC_FALSE; + struct option_cache *oc; + struct data_string data; + uint32_t v6only_wait = 0; + + /* Check if the v6-only-preferred was requested. */ + req = client->config->requested_options; + + if (req == NULL) + return 0; + + for (i = 0 ; req[i] != NULL ; i++) { + if ((req[i]->universe == &dhcp_universe) && + (req[i]->code == DHO_V6_ONLY_PREFERRED)) { + found = ISC_TRUE; + break; + } + } + + if (found == ISC_FALSE) + return 0; + + /* Get the V6ONLY_WAIT timer. */ + oc = lookup_option(&dhcp_universe, packet->options, + DHO_V6_ONLY_PREFERRED); + if (!oc) + return 0; + + memset(&data, 0, sizeof(data)); + + if (evaluate_option_cache(&data, packet, (struct lease *)0, client, + packet->options, (struct option_state *)0, + &global_scope, oc, MDL)) { + if (data.len == 4) { + v6only_wait = getULong(data.data); + if (v6only_wait < MIN_V6ONLY_WAIT) + v6only_wait = MIN_V6ONLY_WAIT; + } + data_string_forget(&data, MDL); + } + + return (v6only_wait); +} + +/* finish_v6only is called when the V6ONLY_WAIT timer expired. */ + +void finish_v6only(cpp) + void *cpp; +{ + struct client_state *client = cpp; + + cancel_timeout(finish_v6only, client); + client->state = S_INIT; + state_init(cpp); +} + +/* + * start_v6only is called when a requested v6-only-preferred option was + * returned by the server. */ + +void start_v6only(client, v6only_wait) + struct client_state *client; + uint32_t v6only_wait; +{ + struct timeval tv; + + /* Enter V6ONLY state. */ + + client->state = S_V6ONLY; + + /* Run the client script. */ + script_init(client, "V6ONLY", NULL); + if (client->active) { + script_write_params(client, "old_", client->active); + destroy_client_lease(client->active); + client->active = NULL; + } + script_write_requested(client); + client_envadd(client, "", "v6-only-preferred", "%lu", + (long unsigned)v6only_wait); + script_go(client); + + /* Trigger finish_v6only after V6ONLY_WAIT seconds. */ + tv.tv_sec = cur_tv.tv_sec + v6only_wait; + tv.tv_usec = cur_tv.tv_usec; + + add_timeout(&tv, finish_v6only, client, 0, 0); +} + /* * state_selecting is called when one or more DHCPOFFER packets have been * received and a configurable period of time has passed. @@ -1336,6 +1451,7 @@ void dhcpack (packet) { struct interface_info *ip = packet -> interface; struct client_state *client; + uint32_t v6only_wait; struct client_lease *lease; struct option_cache *oc; struct data_string ds; @@ -1371,6 +1487,16 @@ void dhcpack (packet) inet_ntoa(packet->raw->yiaddr), piaddr (packet->client_addr)); + /* Check v6only first. */ + v6only_wait = check_v6only(packet, client); + if (v6only_wait > 0) { + log_info("v6 only preferred for %lu seconds.", + (long unsigned)v6only_wait); + cancel_timeout(send_request, client); + start_v6only(client, v6only_wait); + return; + } + lease = packet_to_lease (packet, client); if (!lease) { log_info ("packet_to_lease failed."); @@ -1524,9 +1650,12 @@ void bind_lease (client) script_write_params(client, "alias_", client->alias); /* If the BOUND/RENEW code detects another machine using the - offered address, it exits nonzero. We need to send a - DHCPDECLINE and toss the lease. */ - if (script_go(client)) { + offered address, then per our man page it should exit with + a non-zero status, to which we send a DHCPDECLINE and toss + the lease. A return value of less than zero indicates + the script crashed (e.g. segfault) which script_go will log + but we will ignore here. */ + if (script_go(client) > 0) { make_decline(client, client->new); send_decline(client); destroy_client_lease(client->new); @@ -1649,6 +1778,7 @@ void state_stop (cpp) cancel_timeout(send_discover, client); cancel_timeout(send_request, client); cancel_timeout(state_bound, client); + cancel_timeout(finish_v6only, client); /* If we have an address, unconfigure it. */ if (client->active) { @@ -2008,6 +2138,7 @@ void dhcpoffer (packet) { struct interface_info *ip = packet -> interface; struct client_state *client; + uint32_t v6only_wait; struct client_lease *lease, *lp; struct option **req; int i; @@ -2043,6 +2174,16 @@ void dhcpoffer (packet) inet_ntoa(packet->raw->yiaddr), piaddr(packet->client_addr)); + /* Check v6only first. */ + v6only_wait = check_v6only(packet, client); + if (v6only_wait > 0) { + log_info("%s: v6 only preferred for %lu.", obuf, + (long unsigned)v6only_wait); + cancel_timeout(send_discover, client); + start_v6only(client, v6only_wait); + return; + } + /* If this lease doesn't supply the minimum required DHCPv4 parameters, * ignore it. */ @@ -3258,12 +3399,12 @@ make_client_options(struct client_state *client, struct client_lease *lease, hw_idx = 0; hw_len = client->interface->hw_address.hlen; } - memcpy(&client_identifier.buffer->data + 5 - hw_len, + memcpy(client_identifier.buffer->data + 5 - hw_len, client->interface->hw_address.hbuf + hw_idx, hw_len); /* Add the default duid */ - memcpy(&client_identifier.buffer->data+(1+4), + memcpy(client_identifier.buffer->data + (1 + 4), default_duid.data, default_duid.len); /* And save the option */ @@ -4434,8 +4575,14 @@ int script_go(struct client_state *client) } dfree (envp, MDL); gettimeofday(&cur_tv, NULL); - return (WIFEXITED (wstatus) ? - WEXITSTATUS (wstatus) : -WTERMSIG (wstatus)); + + if (!WIFEXITED(wstatus)) { + int sigval = WTERMSIG(wstatus); + log_error ("script_go script: %s was terminated by signal %d", scriptName, sigval); + return (-sigval); + } + + return (WEXITSTATUS(wstatus)); } void client_envadd (struct client_state *client, @@ -4622,6 +4769,7 @@ void client_location_changed () case S_REBINDING: case S_STOPPED: case S_DECLINING: + case S_V6ONLY: break; } client -> state = S_INIT; @@ -4700,6 +4848,7 @@ void do_release(client) cancel_timeout (state_init, client); cancel_timeout (send_request, client); cancel_timeout (state_reboot, client); + cancel_timeout (finish_v6only, client); client -> state = S_STOPPED; #if defined(DHCPv6) && defined(DHCP4o6) |