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>

3 files changed, 146 insertions, 62 deletions

diff --git a/discover/device-handler.c b/discover/device-handler.c
index f053713..487f2e7 100644
--- a/discover/device-handler.c
+++ b/discover/device-handler.c
@@ -40,8 +40,7 @@
 
 enum default_priority {
 	DEFAULT_PRIORITY_REMOTE		= 1,
-	DEFAULT_PRIORITY_LOCAL_UUID	= 2,
-	DEFAULT_PRIORITY_LOCAL_FIRST	= 3,
+	DEFAULT_PRIORITY_LOCAL_FIRST	= 2,
 	DEFAULT_PRIORITY_LOCAL_LAST	= 0xfe,
 	DEFAULT_PRIORITY_DISABLED	= 0xff,
 };
@@ -462,11 +461,27 @@ static bool ipmi_device_type_matches(enum ipmi_bootdev ipmi_type,
 	return false;
 }
 
-static bool priority_matches(struct boot_priority *prio,
-		struct discover_boot_option *opt)
+static int autoboot_option_priority(const struct config *config,
+				struct discover_boot_option *opt)
 {
-	return prio->type == opt->device->device->type ||
-		prio->type == DEVICE_TYPE_ANY;
+	enum device_type type = opt->device->device->type;
+	const char *uuid = opt->device->uuid;
+	struct autoboot_option *auto_opt;
+	unsigned int i;
+
+	for (i = 0; i < config->n_autoboot_opts; i++) {
+		auto_opt = &config->autoboot_opts[i];
+		if (auto_opt->boot_type == BOOT_DEVICE_UUID)
+			if (!strcmp(auto_opt->uuid, uuid))
+				return DEFAULT_PRIORITY_LOCAL_FIRST + i;
+
+		if (auto_opt->boot_type == BOOT_DEVICE_TYPE)
+			if (auto_opt->type == type ||
+			    auto_opt->type == DEVICE_TYPE_ANY)
+				return DEFAULT_PRIORITY_LOCAL_FIRST + i;
+	}
+
+	return -1;
 }
 
 /*
@@ -478,8 +493,6 @@ static enum default_priority default_option_priority(
 		struct discover_boot_option *opt)
 {
 	const struct config *config;
-	const char *dev_str;
-	unsigned int i;
 
 	config = config_get();
 
@@ -498,25 +511,17 @@ static enum default_priority default_option_priority(
 		return DEFAULT_PRIORITY_DISABLED;
 	}
 
-	/* Next, allow matching by device UUID. If we have one set but it
-	 * doesn't match, disallow the default entirely */
-	dev_str = config->boot_device;
-	if (dev_str && dev_str[0]) {
-		if (!strcmp(opt->device->uuid, dev_str))
-			return DEFAULT_PRIORITY_LOCAL_UUID;
-
-		pb_debug("handler: disabled default priority due to "
-				"non-matching UUID\n");
-		return DEFAULT_PRIORITY_DISABLED;
-	}
-
-	/* Lastly, use the local priorities */
-	for (i = 0; i < config->n_boot_priorities; i++) {
-		struct boot_priority *prio = &config->boot_priorities[i];
-		if (priority_matches(prio, opt))
-			return DEFAULT_PRIORITY_LOCAL_FIRST + prio->priority;
+	/* Next, try to match the option against the user-defined autoboot
+	 * options, either by device UUID or type. */
+	if (config->n_autoboot_opts) {
+		int boot_match = autoboot_option_priority(config, opt);
+		if (boot_match > 0)
+			return boot_match;
 	}
 
+	/* If the option didn't match any entry in the array, it is disabled */
+	pb_debug("handler: disabled default priority due to "
+			"non-matching UUID or type\n");
 	return DEFAULT_PRIORITY_DISABLED;
 }
 
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,
diff --git a/discover/platform.c b/discover/platform.c
index 4451589..74e2a82 100644
--- a/discover/platform.c
+++ b/discover/platform.c
@@ -62,16 +62,13 @@ static void dump_config(struct config *config)
 	for (i = 0; i < config->network.n_dns_servers; i++)
 		pb_log("  dns server %s\n", config->network.dns_servers[i]);
 
-	if (config->boot_device)
-		pb_log("  boot device %s\n", config->boot_device);
-
-	if (config->n_boot_priorities)
-		pb_log(" boot priority order:\n");
-
-	for (i = 0; i < config->n_boot_priorities; i++) {
-		struct boot_priority *prio = &config->boot_priorities[i];
-		pb_log(" %10s: %d\n", device_type_name(prio->type),
-					prio->priority);
+	for (i = 0; i < config->n_autoboot_opts; i++) {
+		if (config->autoboot_opts[i].boot_type == BOOT_DEVICE_TYPE)
+			pb_log("  boot device %d: %s\n", i,
+			       device_type_name(config->autoboot_opts[i].type));
+		else
+			pb_log("  boot device %d: uuid: %s\n",
+			       i, config->autoboot_opts[i].uuid);
 	}
 
 	pb_log("  IPMI boot device 0x%02x%s\n", config->ipmi_bootdev,
@@ -109,17 +106,16 @@ void config_set_defaults(struct config *config)
 	config->network.n_interfaces = 0;
 	config->network.dns_servers = NULL;
 	config->network.n_dns_servers = 0;
-	config->boot_device = NULL;
 	config->safe_mode = false;
 	config->lang = NULL;
 
-	config->n_boot_priorities = 2;
-	config->boot_priorities = talloc_array(config, struct boot_priority,
-						config->n_boot_priorities);
-	config->boot_priorities[0].type = DEVICE_TYPE_NETWORK;
-	config->boot_priorities[0].priority = 0;
-	config->boot_priorities[1].type = DEVICE_TYPE_ANY;
-	config->boot_priorities[1].priority = 1;
+	config->n_autoboot_opts = 2;
+	config->autoboot_opts = talloc_array(config, struct autoboot_option,
+						config->n_autoboot_opts);
+	config->autoboot_opts[0].boot_type = BOOT_DEVICE_TYPE;
+	config->autoboot_opts[0].type = DEVICE_TYPE_NETWORK;
+	config->autoboot_opts[1].boot_type = BOOT_DEVICE_TYPE;
+	config->autoboot_opts[1].type = DEVICE_TYPE_ANY;
 
 	config->ipmi_bootdev = 0;
 	config->ipmi_bootdev_persistent = false;