/* * files.c -- DHCP server file manipulation * * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001 */ #include <sys/socket.h> #include <arpa/inet.h> #include <string.h> #include <stdlib.h> #include <time.h> #include <ctype.h> #include <netdb.h> #include <netinet/ether.h> #include "static_leases.h" #include "dhcpd.h" #include "options.h" #include "files.h" #include "common.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)) { if ((host = gethostbyname(line))) 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; if (*dest) free(*dest); *dest = strdup(line); return 1; } static int read_u32(const char *line, void *arg) { uint32_t *dest = arg; char *endptr; *dest = strtoul(line, &endptr, 0); return endptr[0] == '\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, struct dhcp_option *option, char *buffer, int length) { struct option_set *existing, *new, **curr; /* add it to an existing option */ if ((existing = find_option(*opt_list, option->code))) { DEBUG(LOG_INFO, "Attaching option %s to existing member of list", option->name); if (option->flags & OPTION_LIST) { if (existing->data[OPT_LEN] + length <= 255) { existing->data = realloc(existing->data, existing->data[OPT_LEN] + length + 2); 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 */ } else { DEBUG(LOG_INFO, "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; } } /* 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; 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; if (!(opt = strtok(line, " \t="))) return 0; for (option = dhcp_options; option->code; option++) if (!strcasecmp(option->name, opt)) break; if (!option->code) return 0; do { if (!(val = strtok(NULL, ", \t"))) 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); #ifdef UDHCP_DEBUG printStaticLeases(arg); #endif 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; #ifdef UDHCP_DEBUG char orig[READ_CONFIG_BUF_SIZE]; #endif 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); if (!(in = fopen(file, "r"))) { LOG(LOG_ERR, "unable to open config file: %s", file); return 0; } while (fgets(buffer, READ_CONFIG_BUF_SIZE, in)) { lm++; if (strchr(buffer, '\n')) *(strchr(buffer, '\n')) = '\0'; #ifdef UDHCP_DEBUG strcpy(orig, buffer); #endif if (strchr(buffer, '#')) *(strchr(buffer, '#')) = '\0'; if (!(token = strtok(buffer, " \t"))) continue; if (!(line = strtok(NULL, ""))) continue; /* eat leading whitespace */ line = line + strspn(line, " \t="); /* eat trailing whitespace */ for (i = strlen(line); i > 0 && isspace(line[i - 1]); 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)) { LOG(LOG_ERR, "Failure parsing line %d of %s", lm, file); DEBUG(LOG_ERR, "unable to parse '%s'", orig); /* reset back to the default value */ keywords[i].handler(keywords[i].def, keywords[i].var); } } fclose(in); return 1; } void write_leases(void) { FILE *fp; unsigned int i; char buf[255]; time_t curr = time(0); unsigned long tmp_time; 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) { /* 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); fwrite(&leases[i], sizeof(struct dhcpOfferedAddr), 1, fp); /* Then restore it when done. */ leases[i].expires = tmp_time; } } fclose(fp); if (server_config.notify_file) { sprintf(buf, "%s %s", server_config.notify_file, server_config.lease_file); system(buf); } } void read_leases(const char *file) { FILE *fp; unsigned int i = 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)) { /* 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))) { LOG(LOG_WARNING, "Too many leases while loading %s\n", file); break; } i++; } } DEBUG(LOG_INFO, "Read %d leases", i); fclose(fp); }