lib: Add pb-config module

Add a library for (name, value) configuration.

Different storage backends are allowed (although currently hardcoded to
powerpc nvram), and config is read-only at present.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

6 files changed, 535 insertions, 0 deletions

diff --git a/lib/pb-config/pb-config.c b/lib/pb-config/pb-config.c
new file mode 100644
index 0000000..9f7d240
--- /dev/null
+++ b/lib/pb-config/pb-config.c
@@ -0,0 +1,81 @@
+
+#include <log/log.h>
+#include <talloc/talloc.h>
+
+#include "pb-config.h"
+
+#include "storage.h"
+
+static struct config		*config;
+static struct config_storage	*storage;
+
+
+static void config_set_defaults(struct config *config)
+{
+	config->autoboot_enabled = true;
+	config->network_configs = NULL;
+	config->n_network_configs = 0;
+}
+
+static void dump_config(struct config *config)
+{
+	int i;
+
+	pb_log("configuration:\n");
+
+	pb_log(" autoboot enabled: %s\n",
+			config->autoboot_enabled ? "yes" : "no");
+
+	if (config->n_network_configs > 0)
+		pb_log(" network configuration:\n");
+
+	for (i = 0; i < config->n_network_configs; i++) {
+		struct network_config *netconf = config->network_configs[i];
+
+		pb_log("  interface %02x:%02x:%02x:%02x:%02x:%02x\n",
+				netconf->hwaddr[0], netconf->hwaddr[1],
+				netconf->hwaddr[2], netconf->hwaddr[3],
+				netconf->hwaddr[4], netconf->hwaddr[5]);
+
+		if (netconf->ignore) {
+			pb_log("   ignore\n");
+			continue;
+		}
+
+		if (netconf->method == CONFIG_METHOD_DHCP) {
+			pb_log("   dhcp\n");
+
+		} else if (netconf->method == CONFIG_METHOD_STATIC) {
+			pb_log("   static:\n");
+			pb_log("    ip:  %s\n", netconf->static_config.address);
+			pb_log("    gw:  %s\n", netconf->static_config.gateway);
+			pb_log("    dns: %s\n", netconf->static_config.dns);
+
+		}
+	}
+}
+
+int config_init(void *ctx)
+{
+	config = talloc(ctx, struct config);
+	config_set_defaults(config);
+
+	storage = create_powerpc_nvram_storage(config);
+
+	storage->load(storage, config);
+
+	dump_config(config);
+
+	return 0;
+}
+
+const struct config *config_get(void)
+{
+	return config;
+}
+
+int config_fini(void)
+{
+	talloc_free(config);
+	return 0;
+}
diff --git a/lib/pb-config/pb-config.h b/lib/pb-config/pb-config.h
new file mode 100644
index 0000000..cfcf025
--- /dev/null
+++ b/lib/pb-config/pb-config.h
@@ -0,0 +1,39 @@
+#ifndef CONFIGURATION_H
+#define CONFIGURATION_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define HWADDR_SIZE	6
+
+struct network_config {
+	uint8_t	hwaddr[HWADDR_SIZE];
+	bool	ignore;
+	enum {
+		CONFIG_METHOD_DHCP,
+		CONFIG_METHOD_STATIC,
+	} method;
+	union {
+		struct {
+		} dhcp_config;
+		struct {
+			char *address;
+			char *gateway;
+			char *dns;
+		} static_config;
+	};
+};
+
+struct config {
+	bool			autoboot_enabled;
+	struct network_config	**network_configs;
+	int			n_network_configs;
+};
+
+
+int config_init(void *ctx);
+const struct config *config_get(void);
+int config_fini(void);
+
+#endif /* CONFIGURATION_H */
+
diff --git a/lib/pb-config/storage-null.c b/lib/pb-config/storage-null.c
new file mode 100644
index 0000000..b9fe6ed
--- /dev/null
+++ b/lib/pb-config/storage-null.c
@@ -0,0 +1,19 @@
+
+#include <stdlib.h>
+
+#include "storage.h"
+
+static int load(struct config_storage *st __attribute__((unused)),
+		struct config *config __attribute__((unused)))
+{
+	return 0;
+}
+
+static struct config_storage st = {
+	.load  = load,
+};
+
+struct config_storage *create_null_storage(void *ctx __attribute__((unused)))
+{
+	return &st;
+}
diff --git a/lib/pb-config/storage-powerpc-nvram.c b/lib/pb-config/storage-powerpc-nvram.c
new file mode 100644
index 0000000..4e4d29a
--- /dev/null
+++ b/lib/pb-config/storage-powerpc-nvram.c
@@ -0,0 +1,323 @@
+
+#include <string.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include <talloc/talloc.h>
+#include <list/list.h>
+#include <log/log.h>
+
+#include "pb-config.h"
+#include "storage.h"
+
+static const char *partition = "common";
+static const char *prefix = "petitboot,";
+
+struct param {
+	char			*name;
+	char			*value;
+	bool			modified;
+	struct list_item	list;
+};
+
+struct powerpc_nvram_storage {
+	struct config_storage	storage;
+	struct list		params;
+};
+
+#define to_powerpc_nvram_storage(s) \
+	container_of(s, struct powerpc_nvram_storage, storage)
+
+/* a partition max a max size of 64k * 16bytes = 1M */
+static const int max_partition_size = 64 * 1024 * 16;
+
+static int parse_nvram_params(struct powerpc_nvram_storage *nv,
+		char *buf, int len)
+{
+	char *pos, *name, *value;
+	unsigned int paramlen;
+	int i, count;
+
+	/* discard 2 header lines:
+	 * "common" partiton"
+	 * ------------------
+	 */
+	pos = buf;
+	count = 0;
+
+	for (i = 0; i < len; i++) {
+		if (pos[i] == '\n')
+			count++;
+		if (count == 2)
+			break;
+	}
+
+	if (i == len) {
+		fprintf(stderr, "failure parsing nvram output\n");
+		return -1;
+	}
+
+	for (pos = buf + i; pos < buf + len; pos += paramlen) {
+		unsigned int namelen;
+		struct param *param;
+
+		paramlen = strlen(pos);
+
+		name = pos;
+		value = strchr(pos, '=');
+		if (!value)
+			continue;
+
+		namelen = name - value;
+		if (namelen <= strlen(prefix))
+			continue;
+
+		if (strncmp(name, prefix, strlen(prefix)))
+			continue;
+
+		name += strlen(prefix);
+		value++;
+
+		param = talloc(nv, struct param);
+		param->modified = false;
+		param->name = talloc_strndup(nv, name, namelen);
+		param->value = talloc_strdup(nv, value);
+		list_add(&nv->params, &param->list);
+	}
+
+	return 0;
+}
+
+static int parse_nvram(struct powerpc_nvram_storage *nv)
+{
+	int rc, len, buf_len;
+	int pipefds[2], status;
+	char *buf;
+	pid_t pid;
+
+	rc = pipe(pipefds);
+	if (rc) {
+		perror("pipe");
+		return -1;
+	}
+
+	pid = fork();
+
+	if (pid < 0) {
+		perror("fork");
+		return -1;
+	}
+
+	if (pid == 0) {
+		close(STDIN_FILENO);
+		close(pipefds[0]);
+		dup2(pipefds[1], STDOUT_FILENO);
+		execlp("nvram", "nvram", "--print-config",
+				"--partition", partition, NULL);
+		exit(EXIT_FAILURE);
+	}
+
+	close(pipefds[1]);
+
+	len = 0;
+	buf_len = max_partition_size;
+	buf = talloc_array(nv, char, buf_len);
+
+	for (;;) {
+		rc = read(pipefds[0], buf + len, buf_len - len);
+
+		if (rc < 0) {
+			perror("read");
+			break;
+		}
+
+		if (rc == 0)
+			break;
+
+		len += rc;
+	}
+
+	waitpid(pid, &status, 0);
+	if (!WIFEXITED(status) || WEXITSTATUS(status)) {
+		fprintf(stderr, "nvram process returned "
+				"non-zero exit status\n");
+		return -1;
+	}
+
+	if (rc < 0)
+		return rc;
+
+	return parse_nvram_params(nv, buf, len);
+}
+
+static const char *get_param(struct powerpc_nvram_storage *nv,
+		const char *name)
+{
+	struct param *param;
+
+	list_for_each_entry(&nv->params, param, list)
+		if (!strcmp(param->name, name))
+			return param->value;
+	return NULL;
+}
+
+static int parse_hwaddr(struct network_config *config, char *str)
+{
+	int i;
+
+	if (strlen(str) != strlen("00:00:00:00:00:00"))
+		return -1;
+
+	for (i = 0; i < HWADDR_SIZE; i++) {
+		char byte[3], *endp;
+		unsigned long x;
+
+		byte[0] = str[i * 3 + 0];
+		byte[1] = str[i * 3 + 1];
+		byte[2] = '\0';
+
+		x = strtoul(byte, &endp, 16);
+		if (endp != byte + 2)
+			return -1;
+
+		config->hwaddr[i] = x & 0xff;
+	}
+
+	return 0;
+}
+
+static int parse_one_network_config(struct network_config *config,
+		char *confstr)
+{
+	char *tok, *saveptr;
+
+	if (!confstr || !strlen(confstr))
+		return -1;
+
+	/* first token should be the mac address */
+	tok = strtok_r(confstr, ",", &saveptr);
+	if (!tok)
+		return -1;
+
+	if (parse_hwaddr(config, tok))
+		return -1;
+
+	/* second token is the method */
+	tok = strtok_r(NULL, ",", &saveptr);
+	if (!tok || !strlen(tok) || !strcmp(tok, "ignore")) {
+		config->ignore = true;
+		return 0;
+	}
+
+	if (!strcmp(tok, "dhcp")) {
+		config->method = CONFIG_METHOD_DHCP;
+
+	} else if (!strcmp(tok, "static")) {
+		config->method = CONFIG_METHOD_STATIC;
+
+		/* ip/mask, [optional] gateway, [optional] dns */
+		tok = strtok_r(NULL, ",", &saveptr);
+		if (!tok)
+			return -1;
+		config->static_config.address =
+			talloc_strdup(config, tok);
+
+		tok = strtok_r(NULL, ",", &saveptr);
+		if (tok) {
+			config->static_config.gateway =
+				talloc_strdup(config, tok);
+			tok = strtok_r(NULL, ",", &saveptr);
+		}
+
+		if (tok) {
+			config->static_config.dns =
+				talloc_strdup(config, tok);
+		}
+	} else {
+		pb_log("Unknown network configuration method %s\n", tok);
+		return -1;
+	}
+
+	return 0;
+}
+
+static void populate_network_config(struct powerpc_nvram_storage *nv,
+		struct config *config)
+{
+	const char *cval;
+	char *val;
+	int i;
+
+	cval = get_param(nv, "network");
+	if (!cval || !strlen(cval))
+		return;
+
+	val = talloc_strdup(config, cval);
+
+	for (i = 0; ; i++) {
+		struct network_config *netconf;
+		char *tok, *saveptr;
+		int rc;
+
+		tok = strtok_r(i == 0 ? val : NULL, " ", &saveptr);
+		if (!tok)
+			break;
+
+		netconf = talloc(nv, struct network_config);
+
+		rc = parse_one_network_config(netconf, tok);
+		if (rc) {
+			talloc_free(netconf);
+			continue;
+		}
+
+		config->network_configs = talloc_realloc(nv,
+						config->network_configs,
+						struct network_config *,
+						++config->n_network_configs);
+
+		config->network_configs[config->n_network_configs - 1] =
+						netconf;
+	}
+
+	talloc_free(val);
+}
+
+static void populate_config(struct powerpc_nvram_storage *nv,
+		struct config *config)
+{
+	const char *val;
+
+	/* if the "auto-boot?' property is present and "false", disable auto
+	 * boot */
+	val = get_param(nv, "auto-boot?");
+	config->autoboot_enabled = !val || strcmp(val, "false");
+
+	populate_network_config(nv, config);
+}
+
+static int load(struct config_storage *st, struct config *config)
+{
+	struct powerpc_nvram_storage *nv = to_powerpc_nvram_storage(st);
+	int rc;
+
+	rc = parse_nvram(nv);
+	if (rc)
+		return rc;
+
+	populate_config(nv, config);
+
+	return 0;
+}
+
+struct config_storage *create_powerpc_nvram_storage(void *ctx)
+{
+	struct powerpc_nvram_storage *nv;
+
+	nv = talloc(ctx, struct powerpc_nvram_storage);
+	nv->storage.load = load;
+	list_init(&nv->params);
+
+	return &nv->storage;
+}
diff --git a/lib/pb-config/storage-test.c b/lib/pb-config/storage-test.c
new file mode 100644
index 0000000..ba4e952
--- /dev/null
+++ b/lib/pb-config/storage-test.c
@@ -0,0 +1,56 @@
+
+#include <string.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "pb-config.h"
+#include "storage.h"
+
+struct network_config net1 = {
+	.hwaddr = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+	.method = CONFIG_METHOD_DHCP,
+};
+
+struct network_config net2 = {
+	.hwaddr = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x56 },
+	.method = CONFIG_METHOD_STATIC,
+	.static_config = {
+		.address = "192.168.0.2/24",
+		.gateway = "192.168.0.1",
+	},
+};
+
+struct network_config *network_configs[] = { &net1, &net2 };
+
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
+
+struct config test_config = {
+	.autoboot_enabled = true,
+	.network_configs = network_configs,
+	.n_network_configs = ARRAY_SIZE(network_configs),
+};
+
+struct test_storage {
+	struct config_storage	storage;
+	struct param		*params;
+	int			n_params;
+};
+
+static int load(struct config_storage *st __attribute__((unused)),
+		struct config *config)
+{
+	memcpy(config, &test_config, sizeof(test_config));
+	return 0;
+}
+
+static struct test_storage st = {
+	.storage = {
+		.load  = load,
+	},
+};
+
+struct config_storage *create_test_storage(void *ctx __attribute__((unused)))
+{
+	return &st.storage;
+}
diff --git a/lib/pb-config/storage.h b/lib/pb-config/storage.h
new file mode 100644
index 0000000..a1d5269
--- /dev/null
+++ b/lib/pb-config/storage.h
@@ -0,0 +1,17 @@
+#ifndef STORAGE_H
+#define STORAGE_H
+
+#include <stdbool.h>
+
+struct config;
+
+struct config_storage {
+	int	(*load)(struct config_storage *st, struct config *config);
+};
+
+struct config_storage *create_powerpc_nvram_storage(void *ctx);
+struct config_storage *create_test_storage(void *ctx);
+struct config_storage *create_null_storage(void *ctx);
+
+#endif /* STORAGE_H */
+