#if defined(HAVE_CONFIG_H) #include "config.h" #endif #include #include #include #include #include #include #include #include "device-handler.h" #include "parser.h" #include "parser-conf.h" #include "parser-utils.h" #include "resource.h" #include "paths.h" #include "event.h" #include "user-event.h" #include "network.h" static const char *pxelinux_prefix = "pxelinux.cfg/"; static void pxe_conf_parse_cb(struct load_url_result *result, void *data); struct pxe_parser_info { struct discover_boot_option *opt; const char *default_name; char **pxe_conf_files; struct pb_url *pxe_base_url; int current; }; static void pxe_finish(struct conf_context *conf) { struct pxe_parser_info *info = conf->parser_info; if (info->opt) discover_context_add_boot_option(conf->dc, info->opt); } /* We need a slightly modified version of pb_url_join, to allow for the * pxelinux "::filename" syntax for absolute URLs */ static struct pb_url *pxe_url_join(void *ctx, const struct pb_url *url, const char *s) { struct pb_url *new_url; int len; len = strlen(s); if (len > 2 && s[0] == ':' && s[1] == ':') { char *tmp; if (s[2] == '/') { /* ::/path -> /path */ tmp = talloc_strdup(ctx, s+2); } else { /* ::path -> /path */ tmp = talloc_strdup(ctx, s+1); tmp[0] = '/'; } new_url = pb_url_join(ctx, url, tmp); talloc_free(tmp); } else { const char *tmp; /* strip leading slashes */ for (tmp = s; *tmp == '/'; tmp++) ; new_url = pb_url_join(ctx, url, tmp); } return new_url; } static void pxe_append_string(struct discover_boot_option *opt, const char *str) { if (opt->option->boot_args) opt->option->boot_args = talloc_asprintf_append( opt->option->boot_args, " %s", str); else opt->option->boot_args = talloc_strdup(opt->option, str); } static char *pxe_sysappend_mac(void *ctx, uint8_t *mac) { if (!mac) return NULL; return talloc_asprintf(ctx, "BOOTIF=01-%02x-%02x-%02x-%02x-%02x-%02x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]); } static void pxe_process_sysappend(struct discover_context *ctx, struct discover_boot_option *opt, unsigned long val) { struct event *event = ctx->event; char *str = NULL; if (!event) return; if (val & 0x2) { uint8_t *mac = find_mac_by_name(ctx, device_handler_get_network(ctx->handler), event->device); str = pxe_sysappend_mac(ctx, mac); if (str) { pxe_append_string(opt, str); talloc_free(str); } val &= ~0x2; } if (val) pb_log("pxe: unsupported features requested in " "ipappend/sysappend: 0x%04lx", val); } static void pxe_process_pair(struct conf_context *ctx, const char *name, char *value) { struct pxe_parser_info *parser_info = ctx->parser_info; struct discover_boot_option *opt = parser_info->opt; struct pb_url *url; /* quirk in the syslinux config format: initrd can be separated * by an '=' */ if (!name && !strncasecmp(value, "initrd=", strlen("initrd="))) { name = "initrd"; value += strlen("initrd="); } if (!name) return; if (streq(name, "DEFAULT")) { parser_info->default_name = talloc_strdup(parser_info, value); return; } if (streq(name, "LABEL")) { if (opt) pxe_finish(ctx); opt = discover_boot_option_create(ctx->dc, ctx->dc->device); opt->option->name = talloc_strdup(opt, value); opt->option->id = talloc_asprintf(opt, "%s@%p", ctx->dc->device->device->id, opt); opt->option->is_default = parser_info->default_name && streq(parser_info->default_name, value); parser_info->opt = opt; return; } /* all other parameters need an option */ if (!opt) return; if (streq(name, "KERNEL")) { url = pxe_url_join(ctx->dc, ctx->dc->conf_url, value); opt->boot_image = create_url_resource(opt, url); char* args_sigfile_default = talloc_asprintf(opt, "%s.cmdline.sig", value); url = pxe_url_join(ctx->dc, ctx->dc->conf_url, args_sigfile_default); opt->args_sig_file = create_url_resource(opt, url); talloc_free(args_sigfile_default); } else if (streq(name, "INITRD")) { url = pxe_url_join(ctx->dc, ctx->dc->conf_url, value); opt->initrd = create_url_resource(opt, url); } else if (streq(name, "APPEND")) { char *str, *end; pxe_append_string(opt, value); str = strcasestr(value, "INITRD="); if (str) { str += strlen("INITRD="); end = strchrnul(str, ' '); *end = '\0'; url = pxe_url_join(ctx->dc, ctx->dc->conf_url, str); opt->initrd = create_url_resource(opt, url); } } else if (streq(name, "SYSAPPEND") || streq(name, "IPAPPEND")) { unsigned long type; char *end; type = strtoul(value, &end, 10); if (end != value && !(*end)) pxe_process_sysappend(ctx->dc, opt, type); } else if (streq(name, "DTB") || streq(name, "FDT")) { url = pxe_url_join(ctx->dc, ctx->dc->conf_url, value); opt->dtb = create_url_resource(opt, url); } } static void pxe_load_next_filename(struct conf_context *conf) { struct pxe_parser_info *info = conf->parser_info; struct pb_url *url; if (!info->pxe_conf_files) return; for (; info->pxe_conf_files[info->current]; info->current++) { url = pb_url_join(conf->dc, info->pxe_base_url, info->pxe_conf_files[info->current]); if (!url) continue; if (load_url_async(conf, url, pxe_conf_parse_cb, conf)) break; } return; } /* * Callback for asynchronous loads from pxe_parse() * @param result Result of load_url_async() * @param data Pointer to associated conf_context */ static void pxe_conf_parse_cb(struct load_url_result *result, void *data) { struct conf_context *conf = data; struct device_handler *handler; struct pxe_parser_info *info; char *buf = NULL; int len, rc = 0; if (!data) return; if (result && result->status == LOAD_OK) rc = read_file(conf, result->local, &buf, &len); if (!result || result->status != LOAD_OK || rc) { /* This load failed so try the next available filename */ info = conf->parser_info; if (!info->pxe_conf_files) return; info->current++; pxe_load_next_filename(conf); if (info->pxe_conf_files[info->current] == NULL) { /* Nothing left to try */ goto out_clean; } return; } /* * Parse the first successfully downloaded file. We only want to parse * the first because otherwise we could parse options from both a * machine-specific config and a 'fallback' default config */ conf_parse_buf(conf, buf, len); /* We may be called well after the original caller of iterate_parsers(), * commit any new boot options ourselves */ handler = talloc_parent(conf); device_handler_discover_context_commit(handler, conf->dc); /* * TRANSLATORS: the format specifier in this string in an IP address, * eg. 192.168.1.1 */ device_handler_status_dev_info(handler, conf->dc->device, _("Parsed PXE config from %s"), conf->dc->conf_url->host); talloc_free(buf); out_clean: if (result->cleanup_local) unlink(result->local); talloc_free(conf); } /** * Return a new conf_context and increment the talloc reference count on * the discover_context struct. * @param ctx Parent talloc context * @param orig Original discover_context * @return Pointer to new conf_context */ static struct conf_context *copy_context(void *ctx, struct discover_context *dc) { struct pxe_parser_info *info; struct conf_context *conf; conf = talloc_zero(ctx, struct conf_context); if (!conf) return NULL; conf->get_pair = conf_get_pair_space; conf->process_pair = pxe_process_pair; conf->finish = pxe_finish; info = talloc_zero(conf, struct pxe_parser_info); if (!info) { talloc_free(conf); return NULL; } conf->parser_info = info; /* * The discover_context may be freed once pxe_parse() returns, but the * callback will still need it. Take a reference so that that it will * persist until the last callback completes. */ conf->dc = talloc_reference(conf, dc); return conf; } static int pxe_parse(struct discover_context *dc) { struct pb_url *pxe_base_url; struct conf_context *conf = NULL; struct load_url_result *result; void *ctx = talloc_parent(dc); struct pxe_parser_info *info; char **pxe_conf_files; bool complete_url; /* Expects dhcp event parameters to support network boot */ if (!dc->event) return -1; dc->conf_url = user_event_parse_conf_url(dc, dc->event, &complete_url); if (!dc->conf_url) return -1; /* * Retrieving PXE configs over the network can take some time depending * on factors such as slow network, malformed paths, bad DNS, and * overzealous firewalls. Instead of blocking the discover server while * we wait for these, spawn an asynchronous job that will attempt to * retrieve each possible URL until it successfully finds one, and * parse and process the resulting file in a callback. */ conf = copy_context(ctx, dc); if (!conf) return -1; if (complete_url) { /* we have a complete URL; use this and we're done. */ result = load_url_async(conf->dc, conf->dc->conf_url, pxe_conf_parse_cb, conf); if (!result) { pb_log("load_url_async fails for %s\n", dc->conf_url->path); goto out_conf; } } else { pxe_conf_files = user_event_parse_conf_filenames(dc, dc->event); if (!pxe_conf_files) goto out_conf; pxe_base_url = pb_url_join(dc, dc->conf_url, pxelinux_prefix); if (!pxe_base_url) goto out_pxe_conf; info = conf->parser_info; info->pxe_conf_files = pxe_conf_files; info->pxe_base_url = pxe_base_url; pxe_load_next_filename(conf); } return 0; out_pxe_conf: talloc_free(pxe_conf_files); out_conf: talloc_free(conf); return -1; } static struct parser pxe_parser = { .name = "pxe", .parse = pxe_parse, }; register_parser(pxe_parser);