diff options
| -rw-r--r-- | discover/pxe-parser.c | 93 |
1 files changed, 59 insertions, 34 deletions
diff --git a/discover/pxe-parser.c b/discover/pxe-parser.c index 4aae8b1..4352036 100644 --- a/discover/pxe-parser.c +++ b/discover/pxe-parser.c @@ -22,9 +22,14 @@ 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; + 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) @@ -206,6 +211,27 @@ static void pxe_process_pair(struct conf_context *ctx, } +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() @@ -216,22 +242,35 @@ static void pxe_conf_parse_cb(struct load_url_result *result, void *data) struct conf_context *conf = data; struct device_handler *handler; struct boot_status status = {0}; + struct pxe_parser_info *info; char *buf = NULL; - int len, rc; + int len, rc = 0; if (!data) return; - if (!result || result->status != LOAD_OK) { - talloc_free(conf); + 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; } - rc = read_file(conf, result->local, &buf, &len); - if (rc) { - pb_log("Read failed during pxe callback for %s\n", result->local); - goto out_clean; - } + /* + * 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); @@ -295,11 +334,12 @@ static struct conf_context *copy_context(void *ctx, struct discover_context *dc) static int pxe_parse(struct discover_context *dc) { - struct pb_url *pxe_base_url, *url; - char **pxe_conf_files, **filename; + 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 */ @@ -314,9 +354,9 @@ static int pxe_parse(struct discover_context *dc) * 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 for each URL we can - * parse and process the resulting files in a callback. A separate - * conf_context is created for each job. + * 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) @@ -340,26 +380,11 @@ static int pxe_parse(struct discover_context *dc) if (!pxe_base_url) goto out_pxe_conf; - for (filename = pxe_conf_files; *filename; filename++) { - if (!conf) { - conf = copy_context(ctx, dc); - } - url = pb_url_join(conf->dc, pxe_base_url, *filename); - if (!url) - continue; - result = load_url_async(conf, url, pxe_conf_parse_cb, - conf); - if (!result) { - pb_log("load_url_async fails for %s\n", - conf->dc->conf_url->path); - talloc_free(conf); - } - /* conf now needed by callback, don't reuse */ - conf = NULL; - } + info = conf->parser_info; + info->pxe_conf_files = pxe_conf_files; + info->pxe_base_url = pxe_base_url; - talloc_free(pxe_base_url); - talloc_free(pxe_conf_files); + pxe_load_next_filename(conf); } return 0; |
