/* $OpenBSD: clparse.c,v 1.25 2005/07/16 18:38:45 krw Exp $ */ /* Parser for dhclient config and lease files... */ /* * Copyright (c) 1997 The Internet Software Consortium. * 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. * 3. Neither the name of The Internet Software Consortium nor the names * of its contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM 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 INTERNET SOFTWARE CONSORTIUM 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. * * This software has been written for the Internet Software Consortium * by Ted Lemon in cooperation with Vixie * Enterprises. To learn more about the Internet Software Consortium, * see ``http://www.vix.com/isc''. To learn more about Vixie * Enterprises, see ``http://www.vix.com''. */ #include "dhcpd.h" #include "dhctoken.h" struct client_config top_level_config; struct interface_info *dummy_interfaces; extern struct interface_info *ifi; char client_script_name[] = "/sbin/dhclient-script"; /* * client-conf-file :== client-declarations EOF * client-declarations :== * | client-declaration * | client-declarations client-declaration */ int read_client_conf(void) { FILE *cfile; char *val; int token; struct client_config *config; new_parse(path_dhclient_conf); /* Initialize the top level client configuration. */ memset(&top_level_config, 0, sizeof(top_level_config)); /* Set some defaults... */ top_level_config.timeout = 60; top_level_config.select_interval = 0; top_level_config.reboot_timeout = 10; top_level_config.retry_interval = 300; top_level_config.backoff_cutoff = 15; top_level_config.initial_interval = 3; top_level_config.bootp_policy = ACCEPT; top_level_config.script_name = client_script_name; top_level_config.requested_options [top_level_config.requested_option_count++] = DHO_SUBNET_MASK; top_level_config.requested_options [top_level_config.requested_option_count++] = DHO_BROADCAST_ADDRESS; top_level_config.requested_options [top_level_config.requested_option_count++] = DHO_TIME_OFFSET; top_level_config.requested_options [top_level_config.requested_option_count++] = DHO_ROUTERS; top_level_config.requested_options [top_level_config.requested_option_count++] = DHO_DOMAIN_NAME; top_level_config.requested_options [top_level_config.requested_option_count++] = DHO_DOMAIN_NAME_SERVERS; top_level_config.requested_options [top_level_config.requested_option_count++] = DHO_HOST_NAME; if ((cfile = fopen(path_dhclient_conf, "r")) != NULL) { do { token = peek_token(&val, cfile); if (token == EOF) break; parse_client_statement(cfile, NULL, &top_level_config); } while (1); token = next_token(&val, cfile); /* Clear the peek buffer */ fclose(cfile); } /* * Set up state and config structures for clients that don't * have per-interface configuration declarations. */ config = NULL; if (!ifi->client) { ifi->client = malloc(sizeof(struct client_state)); if (!ifi->client) error("no memory for client state."); memset(ifi->client, 0, sizeof(*(ifi->client))); } if (!ifi->client->config) { if (!config) { config = malloc(sizeof(struct client_config)); if (!config) error("no memory for client config."); memcpy(config, &top_level_config, sizeof(top_level_config)); } ifi->client->config = config; } return (!warnings_occurred); } /* * lease-file :== client-lease-statements EOF * client-lease-statements :== * | client-lease-statements LEASE client-lease-statement */ void read_client_leases(void) { FILE *cfile; char *val; int token; new_parse(path_dhclient_db); /* Open the lease file. If we can't open it, just return - we can safely trust the server to remember our state. */ if ((cfile = fopen(path_dhclient_db, "r")) == NULL) return; do { token = next_token(&val, cfile); if (token == EOF) break; if (token != LEASE) { warning("Corrupt lease file - possible data loss!"); skip_to_semi(cfile); break; } else parse_client_lease_statement(cfile, 0); } while (1); fclose(cfile); } /* * client-declaration :== * SEND option-decl | * DEFAULT option-decl | * SUPERSEDE option-decl | * PREPEND option-decl | * APPEND option-decl | * hardware-declaration | * REQUEST option-list | * REQUIRE option-list | * TIMEOUT number | * RETRY number | * REBOOT number | * SELECT_TIMEOUT number | * SCRIPT string | * interface-declaration | * LEASE client-lease-statement | * ALIAS client-lease-statement */ void parse_client_statement(FILE *cfile, struct interface_info *ip, struct client_config *config) { int token, code; char *val; switch (next_token(&val, cfile)) { case SEND: parse_option_decl(cfile, &config->send_options[0]); return; case DEFAULT: code = parse_option_decl(cfile, &config->defaults[0]); if (code != -1) config->default_actions[code] = ACTION_DEFAULT; return; case SUPERSEDE: code = parse_option_decl(cfile, &config->defaults[0]); if (code != -1) config->default_actions[code] = ACTION_SUPERSEDE; return; case APPEND: code = parse_option_decl(cfile, &config->defaults[0]); if (code != -1) config->default_actions[code] = ACTION_APPEND; return; case PREPEND: code = parse_option_decl(cfile, &config->defaults[0]); if (code != -1) config->default_actions[code] = ACTION_PREPEND; return; case MEDIA: parse_string_list(cfile, &config->media, 1); return; case HARDWARE: if (ip) parse_hardware_param(cfile, &ip->hw_address); else { parse_warn("hardware address parameter %s", "not allowed here."); skip_to_semi(cfile); } return; case REQUEST: config->requested_option_count = parse_option_list(cfile, config->requested_options); return; case REQUIRE: memset(config->required_options, 0, sizeof(config->required_options)); parse_option_list(cfile, config->required_options); return; case TIMEOUT: parse_lease_time(cfile, &config->timeout); return; case RETRY: parse_lease_time(cfile, &config->retry_interval); return; case SELECT_TIMEOUT: parse_lease_time(cfile, &config->select_interval); return; case REBOOT: parse_lease_time(cfile, &config->reboot_timeout); return; case BACKOFF_CUTOFF: parse_lease_time(cfile, &config->backoff_cutoff); return; case INITIAL_INTERVAL: parse_lease_time(cfile, &config->initial_interval); return; case SCRIPT: config->script_name = parse_string(cfile); return; case INTERFACE: if (ip) parse_warn("nested interface declaration."); parse_interface_declaration(cfile, config); return; case LEASE: parse_client_lease_statement(cfile, 1); return; case ALIAS: parse_client_lease_statement(cfile, 2); return; case REJECT: parse_reject_statement(cfile, config); return; default: parse_warn("expecting a statement."); skip_to_semi(cfile); break; } token = next_token(&val, cfile); if (token != SEMI) { parse_warn("semicolon expected."); skip_to_semi(cfile); } } int parse_X(FILE *cfile, u_int8_t *buf, int max) { int token; char *val; int len; token = peek_token(&val, cfile); if (token == NUMBER_OR_NAME || token == NUMBER) { len = 0; do { token = next_token(&val, cfile); if (token != NUMBER && token != NUMBER_OR_NAME) { parse_warn("expecting hexadecimal constant."); skip_to_semi(cfile); return (0); } convert_num(&buf[len], val, 16, 8); if (len++ > max) { parse_warn("hexadecimal constant too long."); skip_to_semi(cfile); return (0); } token = peek_token(&val, cfile); if (token == COLON) token = next_token(&val, cfile); } while (token == COLON); val = (char *)buf; } else if (token == STRING) { token = next_token(&val, cfile); len = strlen(val); if (len + 1 > max) { parse_warn("string constant too long."); skip_to_semi(cfile); return (0); } memcpy(buf, val, len + 1); } else { parse_warn("expecting string or hexadecimal data"); skip_to_semi(cfile); return (0); } return (len); } /* * option-list :== option_name | * option_list COMMA option_name */ int parse_option_list(FILE *cfile, u_int8_t *list) { int ix, i; int token; char *val; ix = 0; do { token = next_token(&val, cfile); if (!is_identifier(token)) { parse_warn("expected option name."); skip_to_semi(cfile); return (0); } for (i = 0; i < 256; i++) if (!strcasecmp(dhcp_options[i].name, val)) break; if (i == 256) { parse_warn("%s: unexpected option name.", val); skip_to_semi(cfile); return (0); } list[ix++] = i; if (ix == 256) { parse_warn("%s: too many options.", val); skip_to_semi(cfile); return (0); } token = next_token(&val, cfile); } while (token == COMMA); if (token != SEMI) { parse_warn("expecting semicolon."); skip_to_semi(cfile); return (0); } return (ix); } /* * interface-declaration :== * INTERFACE string LBRACE client-declarations RBRACE */ void parse_interface_declaration(FILE *cfile, struct client_config *outer_config) { int token; char *val; struct interface_info *ip; token = next_token(&val, cfile); if (token != STRING) { parse_warn("expecting interface name (in quotes)."); skip_to_semi(cfile); return; } ip = interface_or_dummy(val); if (!ip->client) make_client_state(ip); if (!ip->client->config) make_client_config(ip, outer_config); token = next_token(&val, cfile); if (token != LBRACE) { parse_warn("expecting left brace."); skip_to_semi(cfile); return; } do { token = peek_token(&val, cfile); if (token == EOF) { parse_warn("unterminated interface declaration."); return; } if (token == RBRACE) break; parse_client_statement(cfile, ip, ip->client->config); } while (1); token = next_token(&val, cfile); } struct interface_info * interface_or_dummy(char *name) { struct interface_info *ip; /* Find the interface (if any) that matches the name. */ if (!strcmp(ifi->name, name)) return (ifi); /* If it's not a real interface, see if it's on the dummy list. */ for (ip = dummy_interfaces; ip; ip = ip->next) if (!strcmp(ip->name, name)) return (ip); /* * If we didn't find an interface, make a dummy interface as a * placeholder. */ ip = malloc(sizeof(*ip)); if (!ip) error("Insufficient memory to record interface %s", name); memset(ip, 0, sizeof(*ip)); strlcpy(ip->name, name, IFNAMSIZ); ip->next = dummy_interfaces; dummy_interfaces = ip; return (ip); } void make_client_state(struct interface_info *ip) { ip->client = malloc(sizeof(*(ip->client))); if (!ip->client) error("no memory for state on %s", ip->name); memset(ip->client, 0, sizeof(*(ip->client))); } void make_client_config(struct interface_info *ip, struct client_config *config) { ip->client->config = malloc(sizeof(struct client_config)); if (!ip->client->config) error("no memory for config for %s", ip->name); memset(ip->client->config, 0, sizeof(*(ip->client->config))); memcpy(ip->client->config, config, sizeof(*config)); } /* * client-lease-statement :== * RBRACE client-lease-declarations LBRACE * * client-lease-declarations :== * | * client-lease-declaration | * client-lease-declarations client-lease-declaration */ void parse_client_lease_statement(FILE *cfile, int is_static) { struct client_lease *lease, *lp, *pl; struct interface_info *ip; int token; char *val; token = next_token(&val, cfile); if (token != LBRACE) { parse_warn("expecting left brace."); skip_to_semi(cfile); return; } lease = malloc(sizeof(struct client_lease)); if (!lease) error("no memory for lease."); memset(lease, 0, sizeof(*lease)); lease->is_static = is_static; ip = NULL; do { token = peek_token(&val, cfile); if (token == EOF) { parse_warn("unterminated lease declaration."); return; } if (token == RBRACE) break; parse_client_lease_declaration(cfile, lease, &ip); } while (1); token = next_token(&val, cfile); /* If the lease declaration didn't include an interface * declaration that we recognized, it's of no use to us. */ if (!ip) { free_client_lease(lease); return; } /* Make sure there's a client state structure... */ if (!ip->client) make_client_state(ip); /* If this is an alias lease, it doesn't need to be sorted in. */ if (is_static == 2) { ip->client->alias = lease; return; } /* * The new lease may supersede a lease that's not the active * lease but is still on the lease list, so scan the lease list * looking for a lease with the same address, and if we find it, * toss it. */ pl = NULL; for (lp = ip->client->leases; lp; lp = lp->next) { if (lp->address.len == lease->address.len && !memcmp(lp->address.iabuf, lease->address.iabuf, lease->address.len)) { if (pl) pl->next = lp->next; else ip->client->leases = lp->next; free_client_lease(lp); break; } } /* * If this is a preloaded lease, just put it on the list of * recorded leases - don't make it the active lease. */ if (is_static) { lease->next = ip->client->leases; ip->client->leases = lease; return; } /* * The last lease in the lease file on a particular interface is * the active lease for that interface. Of course, we don't * know what the last lease in the file is until we've parsed * the whole file, so at this point, we assume that the lease we * just parsed is the active lease for its interface. If * there's already an active lease for the interface, and this * lease is for the same ip address, then we just toss the old * active lease and replace it with this one. If this lease is * for a different address, then if the old active lease has * expired, we dump it; if not, we put it on the list of leases * for this interface which are still valid but no longer * active. */ if (ip->client->active) { if (ip->client->active->expiry < cur_time) free_client_lease(ip->client->active); else if (ip->client->active->address.len == lease->address.len && !memcmp(ip->client->active->address.iabuf, lease->address.iabuf, lease->address.len)) free_client_lease(ip->client->active); else { ip->client->active->next = ip->client->leases; ip->client->leases = ip->client->active; } } ip->client->active = lease; /* Phew. */ } /* * client-lease-declaration :== * BOOTP | * INTERFACE string | * FIXED_ADDR ip_address | * FILENAME string | * SERVER_NAME string | * OPTION option-decl | * RENEW time-decl | * REBIND time-decl | * EXPIRE time-decl */ void parse_client_lease_declaration(FILE *cfile, struct client_lease *lease, struct interface_info **ipp) { int token; char *val; struct interface_info *ip; switch (next_token(&val, cfile)) { case BOOTP: lease->is_bootp = 1; break; case INTERFACE: token = next_token(&val, cfile); if (token != STRING) { parse_warn("expecting interface name (in quotes)."); skip_to_semi(cfile); break; } ip = interface_or_dummy(val); *ipp = ip; break; case FIXED_ADDR: if (!parse_ip_addr(cfile, &lease->address)) return; break; case MEDIUM: parse_string_list(cfile, &lease->medium, 0); return; case FILENAME: lease->filename = parse_string(cfile); return; case SERVER_NAME: lease->server_name = parse_string(cfile); return; case RENEW: lease->renewal = parse_date(cfile); return; case REBIND: lease->rebind = parse_date(cfile); return; case EXPIRE: lease->expiry = parse_date(cfile); return; case OPTION: parse_option_decl(cfile, lease->options); return; default: parse_warn("expecting lease declaration."); skip_to_semi(cfile); break; } token = next_token(&val, cfile); if (token != SEMI) { parse_warn("expecting semicolon."); skip_to_semi(cfile); } } int parse_option_decl(FILE *cfile, struct option_data *options) { char *val; int token; u_int8_t buf[4]; u_int8_t hunkbuf[1024]; int hunkix = 0; char *fmt; struct iaddr ip_addr; u_int8_t *dp; int len, code; int nul_term = 0; token = next_token(&val, cfile); if (!is_identifier(token)) { parse_warn("expecting identifier after option keyword."); if (token != SEMI) skip_to_semi(cfile); return (-1); } /* Look up the actual option info. */ fmt = NULL; for (code=0; code < 256; code++) if (strcmp(dhcp_options[code].name, val) == 0) break; if (code > 255) { parse_warn("no option named %s", val); skip_to_semi(cfile); return (-1); } /* Parse the option data... */ do { for (fmt = dhcp_options[code].format; *fmt; fmt++) { if (*fmt == 'A') break; switch (*fmt) { case 'X': len = parse_X(cfile, &hunkbuf[hunkix], sizeof(hunkbuf) - hunkix); hunkix += len; break; case 't': /* Text string... */ token = next_token(&val, cfile); if (token != STRING) { parse_warn("expecting string."); skip_to_semi(cfile); return (-1); } len = strlen(val); if (hunkix + len + 1 > sizeof(hunkbuf)) { parse_warn("option data buffer %s", "overflow"); skip_to_semi(cfile); return (-1); } memcpy(&hunkbuf[hunkix], val, len + 1); nul_term = 1; hunkix += len; break; case 'I': /* IP address. */ if (!parse_ip_addr(cfile, &ip_addr)) return (-1); len = ip_addr.len; dp = ip_addr.iabuf; alloc: if (hunkix + len > sizeof(hunkbuf)) { parse_warn("option data buffer " "overflow"); skip_to_semi(cfile); return (-1); } memcpy(&hunkbuf[hunkix], dp, len); hunkix += len; break; case 'L': /* Unsigned 32-bit integer... */ case 'l': /* Signed 32-bit integer... */ token = next_token(&val, cfile); if (token != NUMBER) { need_number: parse_warn("expecting number."); if (token != SEMI) skip_to_semi(cfile); return (-1); } convert_num(buf, val, 0, 32); len = 4; dp = buf; goto alloc; case 's': /* Signed 16-bit integer. */ case 'S': /* Unsigned 16-bit integer. */ token = next_token(&val, cfile); if (token != NUMBER) goto need_number; convert_num(buf, val, 0, 16); len = 2; dp = buf; goto alloc; case 'b': /* Signed 8-bit integer. */ case 'B': /* Unsigned 8-bit integer. */ token = next_token(&val, cfile); if (token != NUMBER) goto need_number; convert_num(buf, val, 0, 8); len = 1; dp = buf; goto alloc; case 'f': /* Boolean flag. */ token = next_token(&val, cfile); if (!is_identifier(token)) { parse_warn("expecting identifier."); bad_flag: if (token != SEMI) skip_to_semi(cfile); return (-1); } if (!strcasecmp(val, "true") || !strcasecmp(val, "on")) buf[0] = 1; else if (!strcasecmp(val, "false") || !strcasecmp(val, "off")) buf[0] = 0; else { parse_warn("expecting boolean."); goto bad_flag; } len = 1; dp = buf; goto alloc; default: warning("Bad format %c in parse_option_param.", *fmt); skip_to_semi(cfile); return (-1); } } token = next_token(&val, cfile); } while (*fmt == 'A' && token == COMMA); if (token != SEMI) { parse_warn("semicolon expected."); skip_to_semi(cfile); return (-1); } options[code].data = malloc(hunkix + nul_term); if (!options[code].data) error("out of memory allocating option data."); memcpy(options[code].data, hunkbuf, hunkix + nul_term); options[code].len = hunkix; return (code); } void parse_string_list(FILE *cfile, struct string_list **lp, int multiple) { int token; char *val; struct string_list *cur, *tmp; /* Find the last medium in the media list. */ if (*lp) for (cur = *lp; cur->next; cur = cur->next) ; /* nothing */ else cur = NULL; do { token = next_token(&val, cfile); if (token != STRING) { parse_warn("Expecting media options."); skip_to_semi(cfile); return; } tmp = malloc(sizeof(struct string_list) + strlen(val)); if (tmp == NULL) error("no memory for string list entry."); strlcpy(tmp->string, val, strlen(val) + 1); tmp->next = NULL; /* Store this medium at the end of the media list. */ if (cur) cur->next = tmp; else *lp = tmp; cur = tmp; token = next_token(&val, cfile); } while (multiple && token == COMMA); if (token != SEMI) { parse_warn("expecting semicolon."); skip_to_semi(cfile); } } void parse_reject_statement(FILE *cfile, struct client_config *config) { int token; char *val; struct iaddr addr; struct iaddrlist *list; do { if (!parse_ip_addr(cfile, &addr)) { parse_warn("expecting IP address."); skip_to_semi(cfile); return; } list = malloc(sizeof(struct iaddrlist)); if (!list) error("no memory for reject list!"); list->addr = addr; list->next = config->reject_list; config->reject_list = list; token = next_token(&val, cfile); } while (token == COMMA); if (token != SEMI) { parse_warn("expecting semicolon."); skip_to_semi(cfile); } }