+/* 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, ctx->network,
+ 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);
+
+}
+