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-rw-r--r--discover/pxe-parser.c93
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;
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