petitboot: Implement ordered boot options

Move petitboot to a more familiar 'boot-order' based autoboot system.
The discover server now reads multiple values from the petitboot,bootdev
parameter and adds them in order to config->autoboot_opts. Boot priority
is determined by the options' position in the list.
On the client, nc-config now recognises the new boot order, and allows
the user to add, remove, and reorder the devices in the list.

Signed-off-by: Samuel Mendoza-Jonas <sam.mj@au1.ibm.com>

1 files changed, 102 insertions, 19 deletions

diff --git a/discover/platform-powerpc.c b/discover/platform-powerpc.c
index 895f0ec..bbffb60 100644
--- a/discover/platform-powerpc.c
+++ b/discover/platform-powerpc.c
@@ -49,6 +49,7 @@ static const char *known_params[] = {
 	"petitboot,network",
 	"petitboot,timeout",
 	"petitboot,bootdev",
+	"petitboot,bootdevs",
 	"petitboot,language",
 	"petitboot,debug?",
 	NULL,
@@ -431,28 +432,86 @@ static int read_bootdev(void *ctx, char **pos, struct autoboot_option *opt)
 
 static void populate_bootdev_config(struct platform_powerpc *platform,
 		struct config *config)
-
 {
+	struct autoboot_option *opt, *new = NULL;
+	char *pos, *end, *old_dev = NULL;
+	const char delim = ' ';
+	unsigned int n_new = 0;
 	const char *val;
+	bool conflict;
 
-	config->boot_device = NULL;
-
+	/* Check for old-style bootdev */
 	val = get_param(platform, "petitboot,bootdev");
-	if (!val || !strlen(val))
-		return;
-
-	if (!strncmp(val, "uuid:", strlen("uuid:"))) {
-		config->boot_device = talloc_strdup(config,
+	if (val && strlen(val)) {
+		pos = talloc_strdup(config, val);
+		if (!strncmp(val, "uuid:", strlen("uuid:")))
+			old_dev = talloc_strdup(config,
 						val + strlen("uuid:"));
-
-	} else if (!strncmp(val, "mac:", strlen("mac:"))) {
-		config->boot_device = talloc_strdup(config,
+		else if (!strncmp(val, "mac:", strlen("mac:")))
+			old_dev = talloc_strdup(config,
 						val + strlen("mac:"));
+	}
 
+	/* Check for ordered bootdevs */
+	val = get_param(platform, "petitboot,bootdevs");
+	if (!val || !strlen(val)) {
+		pos = end = NULL;
 	} else {
-		pb_log("bootdev config is in an unknown format "
-				"(expected uuid:... or mac:...)");
+		pos = talloc_strdup(config, val);
+		end = strchr(pos, '\0');
+	}
+
+	while (pos && pos < end) {
+		opt = talloc(config, struct autoboot_option);
+
+		if (read_bootdev(config, &pos, opt)) {
+			pb_log("bootdev config is in an unknown format "
+			       "(expected uuid:... or mac:...)");
+			talloc_free(opt);
+			if (strchr(pos, delim))
+				continue;
+			return;
+		}
+
+		new = talloc_realloc(config, new, struct autoboot_option,
+				     n_new + 1);
+		new[n_new] = *opt;
+		n_new++;
+		talloc_free(opt);
+
 	}
+
+	if (!n_new && !old_dev) {
+		/* If autoboot has been disabled, clear the default options */
+		if (!config->autoboot_enabled) {
+			talloc_free(config->autoboot_opts);
+			config->n_autoboot_opts = 0;
+		}
+		return;
+	}
+
+	conflict = old_dev && (!n_new ||
+				    new[0].boot_type == BOOT_DEVICE_TYPE ||
+				    /* Canonical UUIDs are 36 characters long */
+				    strncmp(new[0].uuid, old_dev, 36));
+
+	if (!conflict) {
+		talloc_free(config->autoboot_opts);
+		config->autoboot_opts = new;
+		config->n_autoboot_opts = n_new;
+		return;
+	}
+
+	/*
+	 * Difference detected, defer to old format in case it has been updated
+	 * recently
+	 */
+	pb_debug("Old autoboot bootdev detected\n");
+	talloc_free(config->autoboot_opts);
+	config->autoboot_opts = talloc(config, struct autoboot_option);
+	config->autoboot_opts[0].boot_type = BOOT_DEVICE_UUID;
+	config->autoboot_opts[0].uuid = talloc_strdup(config, old_dev);
+	config->n_autoboot_opts = 1;
 }
 
 static void populate_config(struct platform_powerpc *platform,
@@ -578,16 +637,40 @@ static void update_network_config(struct platform_powerpc *platform,
 static void update_bootdev_config(struct platform_powerpc *platform,
 		struct config *config)
 {
-	char *val, *tmp = NULL;
+	char *val = NULL, *boot_str = NULL, *tmp = NULL, *first = NULL;
+	struct autoboot_option *opt;
+	const char delim = ' ';
+	unsigned int i;
 
-	if (!config->boot_device)
-		val = "";
+	if (!config->n_autoboot_opts)
+		first = val = "";
+	else if (config->autoboot_opts[0].boot_type == BOOT_DEVICE_UUID)
+		first = talloc_asprintf(config, "uuid:%s",
+					config->autoboot_opts[0].uuid);
 	else
-		tmp = val = talloc_asprintf(platform,
-				"uuid:%s", config->boot_device);
+		first = "";
+
+	for (i = 0; i < config->n_autoboot_opts; i++) {
+		opt = &config->autoboot_opts[i];
+		switch (opt->boot_type) {
+			case BOOT_DEVICE_TYPE:
+				boot_str = talloc_asprintf(config, "%s%c",
+						device_type_name(opt->type),
+						delim);
+				break;
+			case BOOT_DEVICE_UUID:
+				boot_str = talloc_asprintf(config, "uuid:%s%c",
+						opt->uuid, delim);
+				break;
+			}
+			tmp = val = talloc_asprintf_append(val, boot_str);
+	}
 
-	update_string_config(platform, "petitboot,bootdev", val);
+	update_string_config(platform, "petitboot,bootdevs", val);
+	update_string_config(platform, "petitboot,bootdev", first);
 	talloc_free(tmp);
+	if (boot_str)
+		talloc_free(boot_str);
 }
 
 static int update_config(struct platform_powerpc *platform,