/* * files.c -- DHCP server file manipulation * * Rewrite by Russ Dill July 2001 */ #include #include #include #include #include #include #include #include "debug.h" #include "dhcpd.h" #include "files.h" #include "options.h" #include "leases.h" /* on these functions, make sure you datatype matches */ static int read_ip(char *line, void *arg) { struct in_addr *addr = arg; inet_aton(line, addr); return 1; } static int read_str(char *line, void *arg) { char **dest = arg; int i; if (*dest) free(*dest); *dest = strdup(line); /* elimate trailing whitespace */ for (i = strlen(*dest) - 1; i > 0 && isspace((*dest)[i]); i--); (*dest)[i > 0 ? i + 1 : 0] = '\0'; return 1; } static int read_u32(char *line, void *arg) { u_int32_t *dest = arg; *dest = strtoul(line, NULL, 0); return 1; } static int read_yn(char *line, void *arg) { char *dest = arg; if (!strcasecmp("yes", line) || !strcmp("1", line) || !strcasecmp("true", line)) *dest = 1; else if (!strcasecmp("no", line) || !strcmp("0", line) || !strcasecmp("false", line)) *dest = 0; else return 0; return 1; } /* read a dhcp option and add it to opt_list */ static int read_opt(char *line, void *arg) { struct option_set **opt_list = arg; char *opt, *val; char fail; struct dhcp_option *option = NULL; int length = 0; char buffer[255]; u_int16_t result_u16; int16_t result_s16; u_int32_t result_u32; int32_t result_s32; int i; if (!(opt = strtok(line, " \t="))) return 0; for (i = 0; options[i].code; i++) if (!strcmp(options[i].name, opt)) { option = &(options[i]); break; } if (!option) return 0; do { val = strtok(NULL, ", \t"); if (val) { fail = 0; length = 0; switch (option->flags & TYPE_MASK) { case OPTION_IP: read_ip(val, buffer); break; case OPTION_IP_PAIR: read_ip(val, buffer); if ((val = strtok(NULL, ", \t/-"))) read_ip(val, buffer + 4); else fail = 1; break; case OPTION_STRING: length = strlen(val); if (length > 254) length = 254; memcpy(buffer, val, length); break; case OPTION_BOOLEAN: if (!read_yn(val, buffer)) fail = 1; break; case OPTION_U8: buffer[0] = strtoul(val, NULL, 0); break; case OPTION_U16: result_u16 = htons(strtoul(val, NULL, 0)); memcpy(buffer, &result_u16, 2); break; case OPTION_S16: result_s16 = htons(strtol(val, NULL, 0)); memcpy(buffer, &result_s16, 2); break; case OPTION_U32: result_u32 = htonl(strtoul(val, NULL, 0)); memcpy(buffer, &result_u32, 4); break; case OPTION_S32: result_s32 = htonl(strtol(val, NULL, 0)); memcpy(buffer, &result_s32, 4); break; default: break; } length += option_lengths[option->flags & TYPE_MASK]; if (!fail) attach_option(opt_list, option, buffer, length); } else fail = 1; } while (!fail && option->flags & OPTION_LIST); return 1; } static 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), "/etc/udhcpd.leases"}, {"pid_file", read_str, &(server_config.pid_file), "/var/run/udhcpd.pid"}, {"notify_file", read_str, &(server_config.notify_file), ""}, {"", NULL, NULL, ""} }; int read_config(char *file) { FILE *in; char buffer[80], *token, *line; int i; for (i = 0; strlen(keywords[i].keyword); i++) if (strlen(keywords[i].def)) keywords[i].handler(keywords[i].def, keywords[i].var); if (!(in = fopen(file, "r"))) { LOG(LOG_ERR, "unable to open config file: %s", file); return 0; } while (fgets(buffer, 80, in)) { if (strchr(buffer, '\n')) *(strchr(buffer, '\n')) = '\0'; if (strchr(buffer, '#')) *(strchr(buffer, '#')) = '\0'; token = buffer + strspn(buffer, " \t"); if (*token == '\0') continue; line = token + strcspn(token, " \t="); if (*line == '\0') continue; *line = '\0'; line++; line = line + strspn(line, " \t="); if (*line == '\0') continue; for (i = 0; strlen(keywords[i].keyword); i++) if (!strcasecmp(token, keywords[i].keyword)) keywords[i].handler(line, keywords[i].var); } fclose(in); return 1; } /* the dummy var is here so this can be a signal handler */ void write_leases(int dummy) { FILE *fp; unsigned int i; char buf[255]; time_t curr = time(0); unsigned long lease_time; dummy = 0; if (!(fp = fopen(server_config.lease_file, "w"))) { LOG(LOG_ERR, "Unable to open %s for writing", server_config.lease_file); return; } for (i = 0; i < server_config.max_leases; i++) { if (leases[i].yiaddr != 0) { if (server_config.remaining) { if (lease_expired(&(leases[i]))) lease_time = 0; else lease_time = leases[i].expires - curr; } else lease_time = leases[i].expires; lease_time = htonl(lease_time); fwrite(leases[i].chaddr, 16, 1, fp); fwrite(&(leases[i].yiaddr), 4, 1, fp); fwrite(&lease_time, 4, 1, fp); } } fclose(fp); if (server_config.notify_file) { sprintf(buf, "%s %s", server_config.notify_file, server_config.lease_file); system(buf); } } void read_leases(char *file) { FILE *fp; unsigned int i = 0; time_t curr = time(0); struct dhcpOfferedAddr lease; if (!(fp = fopen(file, "r"))) { LOG(LOG_ERR, "Unable to open %s for reading", file); return; } while (i < server_config.max_leases && (fread(&lease, sizeof lease, 1, fp) == 1)) { if (lease.yiaddr >= server_config.start && lease.yiaddr <= server_config.end) { leases[i].yiaddr = lease.yiaddr; leases[i].expires = ntohl(lease.expires); if (server_config.remaining) leases[i].expires += curr; memcpy(leases[i].chaddr, lease.chaddr, sizeof(lease.chaddr)); i++; } } DEBUG(LOG_INFO, "Read %d leases", i); if (i == server_config.max_leases) { if (fgetc(fp) == EOF) /* might be helpfull to drop expired leases */ LOG(LOG_WARNING, "Too many leases while loading %s\n", file); } fclose(fp); }