discover: Change parsers to explicitly request configuration files

Add a new function parser_request_url() to read the data from
configuration files present remotely. We deprecate
iterate_parser_files() and download_config() functions along with the
'filenames' and 'method' members of the 'parser' structure so that
individual parsers would now require to request the configuration files
data from the parser code and doesn't necessarily export the list of
configuration files.

Add the support to handle incoming DHCP event, done by passing all the
relevant environment variables of the udhcpc to the discover code.
Also, update the pxe parser code to populate the list of configuration
file names as per PXELINUX convention of fallback names using mac and ip
addresses of the booting machine.

Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

1 files changed, 231 insertions, 43 deletions

diff --git a/discover/user-event.c b/discover/user-event.c
index 4b56de4..61008c1 100644
--- a/discover/user-event.c
+++ b/discover/user-event.c
@@ -40,6 +40,9 @@
 #include "user-event.h"
 
 
+#define MAC_ADDR_SIZE	6
+#define IP_ADDR_SIZE	4
+
 struct user_event {
 	struct device_handler *handler;
 	int socket;
@@ -52,8 +55,8 @@ static const char *event_action_name(enum event_action action)
 		return "add";
 	case EVENT_ACTION_REMOVE:
 		return "remove";
-	case EVENT_ACTION_CONF:
-		return "conf";
+	case EVENT_ACTION_DHCP:
+		return "dhcp";
 	default:
 		break;
 	}
@@ -73,27 +76,30 @@ static void user_event_print_event(struct event __attribute__((unused)) *event)
 			event->params[i].name, event->params[i].value);
 }
 
-static enum conf_method parse_conf_method(const char *str)
-{
-
-	if (!strcasecmp(str, "dhcp")) {
-		return CONF_METHOD_DHCP;
-	}
-	return CONF_METHOD_UNKNOWN;
-}
-
 static struct resource *user_event_resource(struct discover_boot_option *opt,
-		struct event *event, const char *param_name)
+		struct event *event)
 {
+	const char *siaddr, *boot_file;
 	struct resource *res;
 	struct pb_url *url;
-	const char *val;
+	char *url_str;
 
-	val = event_get_param(event, param_name);
-	if (!val)
+	siaddr = event_get_param(event, "siaddr");
+	if (!siaddr) {
+		pb_log("%s: next server option not found\n", __func__);
+		return NULL;
+	}
+
+	boot_file = event_get_param(event, "boot_file");
+	if (!boot_file) {
+		pb_log("%s: boot_file not found\n", __func__);
 		return NULL;
+	}
+
+	url_str = talloc_asprintf(opt, "%s%s/%s", "tftp://", siaddr, boot_file);
+	url = pb_url_parse(opt, url_str);
+	talloc_free(url_str);
 
-	url = pb_url_parse(opt, val);
 	if (!url)
 		return NULL;
 
@@ -109,41 +115,55 @@ static struct resource *user_event_resource(struct discover_boot_option *opt,
 static int parse_user_event(struct discover_context *ctx, struct event *event)
 {
 	struct discover_boot_option *d_opt;
+	char *server_ip, *root_dir, *p;
 	struct boot_option *opt;
 	struct device *dev;
-	const char *p;
+	const char *val;
 
 	dev = ctx->device->device;
 
 	d_opt = discover_boot_option_create(ctx, ctx->device);
-	opt = d_opt->option;
-
 	if (!d_opt)
 		goto fail;
 
-	p = event_get_param(event, "name");
+	opt = d_opt->option;
+
+	val = event_get_param(event, "name");
 
-	if (!p) {
+	if (!val) {
 		pb_log("%s: no name found\n", __func__);
-		goto fail;
+		goto fail_opt;
 	}
 
-	opt->id = talloc_asprintf(opt, "%s#%s", dev->id, p);
-	opt->name = talloc_strdup(opt, p);
+	opt->id = talloc_asprintf(opt, "%s#%s", dev->id, val);
+	opt->name = talloc_strdup(opt, val);
 
-	d_opt->boot_image = user_event_resource(d_opt, event, "image");
+	d_opt->boot_image = user_event_resource(d_opt, event);
 	if (!d_opt->boot_image) {
 		pb_log("%s: no boot image found for %s!\n", __func__,
 				opt->name);
-		goto fail;
+		goto fail_opt;
 	}
 
-	d_opt->initrd = user_event_resource(d_opt, event, "initrd");
-
-	p = event_get_param(event, "args");
-
-	if (p)
-		opt->boot_args = talloc_strdup(opt, p);
+	val = event_get_param(event, "rootpath");
+	if (val) {
+		server_ip = talloc_strdup(opt, val);
+		p = strchr(server_ip, ':');
+		if (p) {
+			root_dir = talloc_strdup(opt, p + 1);
+			*p = '\0';
+			opt->boot_args = talloc_asprintf(opt, "%s%s:%s",
+					"root=/dev/nfs ip=any nfsroot=",
+					server_ip, root_dir);
+
+			talloc_free(root_dir);
+		} else {
+			opt->boot_args = talloc_asprintf(opt, "%s",
+					"root=/dev/nfs ip=any nfsroot=");
+		}
+
+		talloc_free(server_ip);
+	}
 
 	opt->description = talloc_asprintf(opt, "%s %s", opt->boot_image_file,
 		opt->boot_args ? : "");
@@ -155,16 +175,189 @@ static int parse_user_event(struct discover_context *ctx, struct event *event)
 
 	return 0;
 
-fail:
+fail_opt:
 	talloc_free(d_opt);
+fail:
 	return -1;
 }
 
+static const char *parse_host_addr(struct event *event)
+{
+	const char *val;
+
+	val = event_get_param(event, "tftp");
+	if (val)
+		return val;
+
+	val = event_get_param(event, "siaddr");
+	if (val)
+		return val;
+
+	val = event_get_param(event, "serverid");
+	if (val)
+		return val;
+
+	return NULL;
+}
+
+static char *parse_mac_addr(struct discover_context *ctx, const char *mac)
+{
+	unsigned int mac_addr_arr[MAC_ADDR_SIZE];
+	char *mac_addr;
+
+	sscanf(mac, "%X:%X:%X:%X:%X:%X", mac_addr_arr, mac_addr_arr + 1,
+			mac_addr_arr + 2, mac_addr_arr + 3, mac_addr_arr + 4,
+			mac_addr_arr + 5);
+
+	mac_addr = talloc_asprintf(ctx, "01-%02X-%02X-%02X-%02X-%02X-%02X",
+			mac_addr_arr[0], mac_addr_arr[1], mac_addr_arr[2],
+			mac_addr_arr[3], mac_addr_arr[4], mac_addr_arr[5]);
+
+	return mac_addr;
+}
+
+static char *parse_ip_addr(struct discover_context *ctx, const char *ip)
+{
+	unsigned int ip_addr_arr[IP_ADDR_SIZE];
+	char *ip_hex;
+
+	sscanf(ip, "%u.%u.%u.%u", ip_addr_arr, ip_addr_arr + 1,
+			ip_addr_arr + 2, ip_addr_arr + 3);
+
+	ip_hex = talloc_asprintf(ctx, "%02X%02X%02X%02X", ip_addr_arr[0],
+			ip_addr_arr[1], ip_addr_arr[2], ip_addr_arr[3]);
+
+	return ip_hex;
+}
+
+struct pb_url *user_event_parse_conf_url(struct discover_context *ctx,
+		struct event *event)
+{
+	const char *conffile, *host, *bootfile;
+	char *p, *basedir, *url_str;
+	struct pb_url *url;
+
+	conffile = event_get_param(event, "conffile");
+	if (conffile) {
+		if (is_url(conffile)) {
+			url = pb_url_parse(ctx, conffile);
+		} else {
+			host = parse_host_addr(event);
+			if (!host) {
+				pb_log("%s: host address not found\n",
+						__func__);
+				return NULL;
+			}
+
+			url_str = talloc_asprintf(ctx, "%s%s/%s", "tftp://",
+					host, conffile);
+			url = pb_url_parse(ctx, url_str);
+
+			talloc_free(url_str);
+		}
+
+		ctx->conf_url = url;
+	} else {
+		host = parse_host_addr(event);
+		if (!host) {
+			pb_log("%s: host address not found\n", __func__);
+			return NULL;
+		}
+
+		bootfile = event_get_param(event, "bootfile");
+		if (!bootfile) {
+			pb_log("%s: bootfile param not found\n", __func__);
+			return NULL;
+		}
+
+		basedir = talloc_strdup(ctx, bootfile);
+		p = strchr(basedir, '/');
+		if (p)
+			*p = '\0';
+
+		if (!strcmp(basedir,"") || !strcmp(basedir, "."))
+			url_str = talloc_asprintf(ctx, "%s%s/", "tftp://",host);
+		else
+			url_str = talloc_asprintf(ctx, "%s%s/%s/", "tftp://",host,
+					basedir);
+
+		url = pb_url_parse(ctx, url_str);
+
+		talloc_free(url_str);
+		talloc_free(basedir);
+	}
+
+	return url;
+}
+
+char **user_event_parse_conf_filenames(
+		struct discover_context *ctx, struct event *event)
+{
+	char *mac_addr, *ip_hex;
+	const char *mac, *ip;
+	char **filenames;
+	int index, len;
+
+	mac = event_get_param(event, "mac");
+	if (mac)
+		mac_addr = parse_mac_addr(ctx, mac);
+	else
+		mac_addr = NULL;
+
+	ip = event_get_param(event, "ip");
+	if (ip) {
+		ip_hex = parse_ip_addr(ctx, ip);
+		len = strlen(ip_hex);
+	} else {
+		ip_hex = NULL;
+		len = 0;
+	}
+
+	if (!mac_addr && !ip_hex) {
+		pb_log("%s: neither mac nor ip parameter found\n", __func__);
+		return NULL;
+	}
+
+	/* Filenames as fallback IP's + mac + default */
+	filenames = talloc_array(ctx, char *, len + 3);
+
+	index = 0;
+	if (mac_addr)
+		filenames[index++] = talloc_strdup(filenames, mac_addr);
+
+	while (len) {
+		filenames[index++] = talloc_strdup(filenames, ip_hex);
+		ip_hex[--len] = '\0';
+	}
+
+	filenames[index++] = talloc_strdup(filenames, "default");
+	filenames[index++] = NULL;
+
+	if (mac_addr)
+		talloc_free(mac_addr);
+
+	if (ip_hex)
+		talloc_free(ip_hex);
+
+	return filenames;
+}
+
+static int user_event_dhcp(struct user_event *uev, struct event *event)
+{
+	struct device_handler *handler = uev->handler;
+	struct discover_device *dev;
+
+	dev = discover_device_create(handler, event->device);
+
+	device_handler_dhcp(handler, dev, event);
+
+	return 0;
+}
+
 static int user_event_conf(struct user_event *uev, struct event *event)
 {
 	struct device_handler *handler = uev->handler;
 	struct discover_device *dev;
-	enum conf_method method;
 	struct pb_url *url;
 	const char *val;
 
@@ -176,17 +369,9 @@ static int user_event_conf(struct user_event *uev, struct event *event)
 	if (!url)
 		return 0;
 
-	val = event_get_param(event, "method");
-	if (!val)
-		return 0;
-
-	method = parse_conf_method(val);
-	if (method == CONF_METHOD_UNKNOWN)
-		return 0;
-
 	dev = discover_device_create(handler, event->device);
 
-	device_handler_conf(handler, dev, url, method);
+	device_handler_conf(handler, dev, url);
 
 	return 0;
 }
@@ -249,6 +434,9 @@ static void user_event_handle_message(struct user_event *uev, char *buf,
 	case EVENT_ACTION_CONF:
 		result = user_event_conf(uev, event);
 		break;
+	case EVENT_ACTION_DHCP:
+		result = user_event_dhcp(uev, event);
+		break;
 	default:
 		break;
 	}