/* vi: set sw=4 ts=4: */ /* * files.c -- DHCP server file manipulation * * Rewrite by Russ Dill July 2001 */ #include #include "common.h" #include "dhcpd.h" #include "options.h" /* * Domain names may have 254 chars, and string options can be 254 * chars long. However, 80 bytes will be enough for most, and won't * hog up memory. If you have a special application, change it */ #define READ_CONFIG_BUF_SIZE 80 /* on these functions, make sure you datatype matches */ static int read_ip(const char *line, void *arg) { struct in_addr *addr = arg; struct hostent *host; int retval = 1; if (!inet_aton(line, addr)) { host = gethostbyname(line); if (host) addr->s_addr = *((unsigned long *) host->h_addr_list[0]); else retval = 0; } return retval; } static int read_mac(const char *line, void *arg) { uint8_t *mac_bytes = arg; struct ether_addr *temp_ether_addr; int retval = 1; temp_ether_addr = ether_aton(line); if (temp_ether_addr == NULL) retval = 0; else memcpy(mac_bytes, temp_ether_addr, 6); return retval; } static int read_str(const char *line, void *arg) { char **dest = arg; free(*dest); *dest = xstrdup(line); return 1; } static int read_u32(const char *line, void *arg) { *((uint32_t*)arg) = bb_strtou32(line, NULL, 10); return errno == 0; } static int read_yn(const char *line, void *arg) { char *dest = arg; int retval = 1; if (!strcasecmp("yes", line)) *dest = 1; else if (!strcasecmp("no", line)) *dest = 0; else retval = 0; return retval; } /* find option 'code' in opt_list */ struct option_set *find_option(struct option_set *opt_list, char code) { while (opt_list && opt_list->data[OPT_CODE] < code) opt_list = opt_list->next; if (opt_list && opt_list->data[OPT_CODE] == code) return opt_list; else return NULL; } /* add an option to the opt_list */ static void attach_option(struct option_set **opt_list, const struct dhcp_option *option, char *buffer, int length) { struct option_set *existing, *new, **curr; existing = find_option(*opt_list, option->code); if (!existing) { DEBUG("Attaching option %s to list", option->name); /* make a new option */ new = xmalloc(sizeof(struct option_set)); new->data = xmalloc(length + 2); new->data[OPT_CODE] = option->code; new->data[OPT_LEN] = length; memcpy(new->data + 2, buffer, length); curr = opt_list; while (*curr && (*curr)->data[OPT_CODE] < option->code) curr = &(*curr)->next; new->next = *curr; *curr = new; return; } /* add it to an existing option */ DEBUG("Attaching option %s to existing member of list", option->name); if (option->flags & OPTION_LIST) { if (existing->data[OPT_LEN] + length <= 255) { existing->data = xrealloc(existing->data, existing->data[OPT_LEN] + length + 3); if ((option->flags & TYPE_MASK) == OPTION_STRING) { /* ' ' can bring us to 256 - bad */ if (existing->data[OPT_LEN] + length >= 255) return; /* add space separator between STRING options in a list */ existing->data[existing->data[OPT_LEN] + 2] = ' '; existing->data[OPT_LEN]++; } memcpy(existing->data + existing->data[OPT_LEN] + 2, buffer, length); existing->data[OPT_LEN] += length; } /* else, ignore the data, we could put this in a second option in the future */ } /* else, ignore the new data */ } /* read a dhcp option and add it to opt_list */ static int read_opt(const char *const_line, void *arg) { struct option_set **opt_list = arg; char *opt, *val, *endptr; const struct dhcp_option *option; int retval = 0, length; char buffer[8]; char *line; uint16_t *result_u16 = (uint16_t *) buffer; uint32_t *result_u32 = (uint32_t *) buffer; /* Cheat, the only const line we'll actually get is "" */ line = (char *) const_line; opt = strtok(line, " \t="); if (!opt) return 0; option = dhcp_options; while (1) { if (!option->code) return 0; if (!strcasecmp(option->name, opt)) break; option++; } do { val = strtok(NULL, ", \t"); if (!val) break; length = option_lengths[option->flags & TYPE_MASK]; retval = 0; opt = buffer; /* new meaning for variable opt */ switch (option->flags & TYPE_MASK) { case OPTION_IP: retval = read_ip(val, buffer); break; case OPTION_IP_PAIR: retval = read_ip(val, buffer); if (!(val = strtok(NULL, ", \t/-"))) retval = 0; if (retval) retval = read_ip(val, buffer + 4); break; case OPTION_STRING: length = strlen(val); if (length > 0) { if (length > 254) length = 254; opt = val; retval = 1; } break; case OPTION_BOOLEAN: retval = read_yn(val, buffer); break; case OPTION_U8: buffer[0] = strtoul(val, &endptr, 0); retval = (endptr[0] == '\0'); break; case OPTION_U16: *result_u16 = htons(strtoul(val, &endptr, 0)); retval = (endptr[0] == '\0'); break; case OPTION_S16: *result_u16 = htons(strtol(val, &endptr, 0)); retval = (endptr[0] == '\0'); break; case OPTION_U32: *result_u32 = htonl(strtoul(val, &endptr, 0)); retval = (endptr[0] == '\0'); break; case OPTION_S32: *result_u32 = htonl(strtol(val, &endptr, 0)); retval = (endptr[0] == '\0'); break; default: break; } if (retval) attach_option(opt_list, option, opt, length); } while (retval && option->flags & OPTION_LIST); return retval; } static int read_staticlease(const char *const_line, void *arg) { char *line; char *mac_string; char *ip_string; uint8_t *mac_bytes; uint32_t *ip; /* Allocate memory for addresses */ mac_bytes = xmalloc(sizeof(unsigned char) * 8); ip = xmalloc(sizeof(uint32_t)); /* Read mac */ line = (char *) const_line; mac_string = strtok(line, " \t"); read_mac(mac_string, mac_bytes); /* Read ip */ ip_string = strtok(NULL, " \t"); read_ip(ip_string, ip); addStaticLease(arg, mac_bytes, ip); if (ENABLE_FEATURE_UDHCP_DEBUG) printStaticLeases(arg); return 1; } static const struct config_keyword keywords[] = { /* keyword handler variable address default */ {"start", read_ip, &(server_config.start), "192.168.0.20"}, {"end", read_ip, &(server_config.end), "192.168.0.254"}, {"interface", read_str, &(server_config.interface), "eth0"}, {"option", read_opt, &(server_config.options), ""}, {"opt", read_opt, &(server_config.options), ""}, {"max_leases", read_u32, &(server_config.max_leases), "254"}, {"remaining", read_yn, &(server_config.remaining), "yes"}, {"auto_time", read_u32, &(server_config.auto_time), "7200"}, {"decline_time",read_u32, &(server_config.decline_time),"3600"}, {"conflict_time",read_u32,&(server_config.conflict_time),"3600"}, {"offer_time", read_u32, &(server_config.offer_time), "60"}, {"min_lease", read_u32, &(server_config.min_lease), "60"}, {"lease_file", read_str, &(server_config.lease_file), LEASES_FILE}, {"pidfile", read_str, &(server_config.pidfile), "/var/run/udhcpd.pid"}, {"notify_file", read_str, &(server_config.notify_file), ""}, {"siaddr", read_ip, &(server_config.siaddr), "0.0.0.0"}, {"sname", read_str, &(server_config.sname), ""}, {"boot_file", read_str, &(server_config.boot_file), ""}, {"static_lease",read_staticlease, &(server_config.static_leases), ""}, /*ADDME: static lease */ {"", NULL, NULL, ""} }; int read_config(const char *file) { FILE *in; char buffer[READ_CONFIG_BUF_SIZE], *token, *line; int i, lm = 0; for (i = 0; keywords[i].keyword[0]; i++) if (keywords[i].def[0]) keywords[i].handler(keywords[i].def, keywords[i].var); in = fopen(file, "r"); if (!in) { bb_error_msg("cannot open config file: %s", file); return 0; } while (fgets(buffer, READ_CONFIG_BUF_SIZE, in)) { char debug_orig[READ_CONFIG_BUF_SIZE]; char *p; lm++; p = strchr(buffer, '\n'); if (p) *p = '\0'; if (ENABLE_FEATURE_UDHCP_DEBUG) strcpy(debug_orig, buffer); p = strchr(buffer, '#'); if (p) *p = '\0'; if (!(token = strtok(buffer, " \t"))) continue; if (!(line = strtok(NULL, ""))) continue; /* eat leading whitespace */ line = skip_whitespace(line); /* eat trailing whitespace */ i = strlen(line) - 1; while (i >= 0 && isspace(line[i])) line[i--] = '\0'; for (i = 0; keywords[i].keyword[0]; i++) if (!strcasecmp(token, keywords[i].keyword)) if (!keywords[i].handler(line, keywords[i].var)) { bb_error_msg("cannot parse line %d of %s", lm, file); if (ENABLE_FEATURE_UDHCP_DEBUG) bb_error_msg("cannot parse '%s'", debug_orig); /* reset back to the default value */ keywords[i].handler(keywords[i].def, keywords[i].var); } } fclose(in); return 1; } void write_leases(void) { int fp; unsigned i; time_t curr = time(0); unsigned long tmp_time; fp = open(server_config.lease_file, O_WRONLY|O_CREAT|O_TRUNC, 0666); if (fp < 0) { bb_error_msg("cannot open %s for writing", server_config.lease_file); return; } for (i = 0; i < server_config.max_leases; i++) { if (leases[i].yiaddr != 0) { /* screw with the time in the struct, for easier writing */ tmp_time = leases[i].expires; if (server_config.remaining) { if (lease_expired(&(leases[i]))) leases[i].expires = 0; else leases[i].expires -= curr; } /* else stick with the time we got */ leases[i].expires = htonl(leases[i].expires); // FIXME: error check?? full_write(fp, &leases[i], sizeof(leases[i])); /* then restore it when done */ leases[i].expires = tmp_time; } } close(fp); if (server_config.notify_file) { char *cmd = xasprintf("%s %s", server_config.notify_file, server_config.lease_file); system(cmd); free(cmd); } } void read_leases(const char *file) { int fp; unsigned int i = 0; struct dhcpOfferedAddr lease; fp = open(file, O_RDONLY); if (fp < 0) { bb_error_msg("cannot open %s for reading", file); return; } while (i < server_config.max_leases && full_read(fp, &lease, sizeof(lease)) == sizeof(lease) ) { /* ADDME: is it a static lease */ if (lease.yiaddr >= server_config.start && lease.yiaddr <= server_config.end) { lease.expires = ntohl(lease.expires); if (!server_config.remaining) lease.expires -= time(0); if (!(add_lease(lease.chaddr, lease.yiaddr, lease.expires))) { bb_error_msg("too many leases while loading %s", file); break; } i++; } } DEBUG("Read %d leases", i); close(fp); }