parsers: change parser.parse to accept a buffer

Rather than having each of the parsers do their own open(), read(), etc,
use the registered filenames array to find & open parser conf files.

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

7 files changed, 108 insertions, 104 deletions

diff --git a/discover/grub2-parser.c b/discover/grub2-parser.c
index 6ef5945..3c756c1 100644
--- a/discover/grub2-parser.c
+++ b/discover/grub2-parser.c
@@ -156,11 +156,10 @@ static const char *grub2_known_names[] = {
 	NULL
 };
 
-static int grub2_parse(struct discover_context *dc)
+static int grub2_parse(struct discover_context *dc, char *buf, int len)
 {
 	struct conf_context *conf;
 	struct grub2_state *state;
-	int rc;
 
 	conf = talloc_zero(dc, struct conf_context);
 
@@ -169,7 +168,6 @@ static int grub2_parse(struct discover_context *dc)
 
 	conf->dc = dc;
 	conf_init_global_options(conf);
-	conf->conf_files = grub2_conf_files,
 	conf->get_pair = conf_get_pair_space;
 	conf->process_pair = grub2_process_pair;
 	conf->finish = grub2_finish;
@@ -182,10 +180,10 @@ static int grub2_parse(struct discover_context *dc)
 	state->opt = talloc_zero(conf->dc->device, struct boot_option);
 	state->opt->boot_args = talloc_strdup(state->opt, "");
 
-	rc = conf_parse(conf);
+	conf_parse_buf(conf, buf, len);
 
 	talloc_free(conf);
-	return rc;
+	return 1;
 }
 
 struct parser __grub2_parser = {
diff --git a/discover/kboot-parser.c b/discover/kboot-parser.c
index c828e30..b28603e 100644
--- a/discover/kboot-parser.c
+++ b/discover/kboot-parser.c
@@ -133,10 +133,9 @@ static const char *const kboot_ignored_names[] = {
 	NULL
 };
 
-static int kboot_parse(struct discover_context *dc)
+static int kboot_parse(struct discover_context *dc, char *buf, int len)
 {
 	struct conf_context *conf;
-	int rc;
 
 	conf = talloc_zero(dc, struct conf_context);
 
@@ -146,15 +145,14 @@ static int kboot_parse(struct discover_context *dc)
 	conf->dc = dc;
 	conf->global_options = kboot_global_options,
 	conf_init_global_options(conf);
-	conf->conf_files = kboot_conf_files,
 	conf->get_pair = conf_get_pair_equal;
 	conf->process_pair = kboot_process_pair;
 	conf->parser_info = (void *)kboot_ignored_names,
 
-	rc = conf_parse(conf);
+	conf_parse_buf(conf, buf, len);
 
 	talloc_free(conf);
-	return rc;
+	return 1;
 }
 
 struct parser __kboot_parser = {
diff --git a/discover/parser-conf.c b/discover/parser-conf.c
index 247e29d..94612c3 100644
--- a/discover/parser-conf.c
+++ b/discover/parser-conf.c
@@ -220,14 +220,15 @@ const char *conf_get_global_option(struct conf_context *conf,
  * Called from conf_parse() with data read from a conf file.
  */
 
-static void conf_parse_buf(struct conf_context *conf)
+void conf_parse_buf(struct conf_context *conf, char *buf,
+		int len __attribute__((unused)))
 {
 	char *pos, *name, *value;
 
 	assert(conf->get_pair);
 	assert(conf->process_pair);
 
-	for (pos = conf->buf; pos;) {
+	for (pos = buf; pos;) {
 		pos = conf->get_pair(conf, pos, &name, &value, '\n');
 
 		if (!value)
@@ -245,82 +246,3 @@ static void conf_parse_buf(struct conf_context *conf)
 	if (conf->finish)
 		conf->finish(conf);
 }
-
-/**
- * conf_parse - The common parser entry.
- *
- * Called from the parser specific setup routines.  Searches for .conf
- * files, reads data into buffers, and calls conf_parse_buf().
- */
-
-int conf_parse(struct conf_context *conf)
-{
-	struct device *dev;
-	int fd, rc;
-	unsigned int i;
-	struct stat stat;
-	ssize_t len;
-
-	rc = 0;
-	fd = -1;
-	len = 0;
-
-	/* The parser is only run on the first file found. */
-	/* FIXME: Could try others on error, etc. */
-
-	for (i = 0; conf->conf_files[i]; i++) {
-		char *filepath = resolve_path(conf->dc,
-			conf->conf_files[i], conf->dc->device->device_path);
-
-		pb_log("%s: try: %s\n", __func__, filepath);
-
-		fd = open(filepath, O_RDONLY);
-
-		talloc_free(filepath);
-
-		if (fd < 0) {
-			pb_log("%s: open failed: %s\n", __func__,
-				strerror(errno));
-			continue;
-		}
-
-		if (fstat(fd, &stat)) {
-			pb_log("%s: fstat failed: %s\n", __func__,
-				strerror(errno));
-			continue;
-		}
-
-		conf->buf = talloc_array(conf, char, stat.st_size + 1);
-
-		len = read(fd, conf->buf, stat.st_size);
-
-		if (len < 0) {
-			pb_log("%s: read failed: %s\n", __func__,
-				strerror(errno));
-			continue;
-		}
-		conf->buf[len] = 0;
-
-		break;
-	}
-
-	if (fd >= 0)
-		close(fd);
-
-	if (len <= 0)
-		goto out;
-
-	dev = conf->dc->device->device;
-	if (!dev->icon_file)
-		dev->icon_file = talloc_strdup(dev,
-			generic_icon_file(guess_device_type(conf->dc)));
-
-	conf_parse_buf(conf);
-
-	rc = 1;
-
-out:
-	pb_log("%s: %s\n", __func__, (rc ? "ok" : "failed"));
-	return rc;
-}
-
diff --git a/discover/parser-conf.h b/discover/parser-conf.h
index efeb4f3..3704bcb 100644
--- a/discover/parser-conf.h
+++ b/discover/parser-conf.h
@@ -29,9 +29,7 @@ struct conf_global_option {
 struct conf_context {
 	void *parser_info;
 	struct discover_context *dc;
-	char *buf;
 	struct conf_global_option *global_options;
-	const char *const *conf_files;
 
 	char *(*get_pair)(struct conf_context *conf, char *str, char **name_out,
 		char **value_out, char terminator);
@@ -40,7 +38,7 @@ struct conf_context {
 	void (*finish)(struct conf_context *conf);
 };
 
-int conf_parse(struct conf_context *conf);
+void conf_parse_buf(struct conf_context *conf, char *buf, int len);
 char *conf_get_pair(struct conf_context *conf, char *str, char **name_out,
 	char **value_out, char delimiter, char terminator);
 void conf_init_global_options(struct conf_context *conf);
diff --git a/discover/parser.c b/discover/parser.c
index 5f4e514..1f3674d 100644
--- a/discover/parser.c
+++ b/discover/parser.c
@@ -1,12 +1,17 @@
 
+#include <fcntl.h>
 #include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
 
 #include "types/types.h"
 #include <log/log.h>
+#include <talloc/talloc.h>
 
 #include "device-handler.h"
 #include "parser.h"
 #include "parser-utils.h"
+#include "paths.h"
 
 struct parser __grub2_parser;
 struct parser __kboot_parser;
@@ -21,19 +26,103 @@ static const struct parser *const parsers[] = {
 	NULL
 };
 
+static const int max_file_size = 1024 * 1024;
+
+static int read_file(struct discover_context *ctx,
+		const char *filename, char **bufp, int *lenp)
+{
+	struct stat statbuf;
+	int rc, fd, i, len;
+	char *buf;
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		return -1;
+
+	rc = fstat(fd, &statbuf);
+	if (rc < 0)
+		goto err_close;
+
+	len = statbuf.st_size;
+	if (len > max_file_size)
+		goto err_close;
+
+	buf = talloc_array(ctx, char, len);
+	if (!buf)
+		goto err_close;
+
+	for (i = 0; i < len; i += rc) {
+		rc = read(fd, buf + i, len - i);
+
+		/* unexpected EOF: trim and return */
+		if (rc == 0) {
+			len = i;
+			break;
+		}
+
+		if (rc < 0)
+			goto err_free;
+
+	}
+
+	close(fd);
+	*bufp = buf;
+	*lenp = len;
+	return 0;
+
+err_free:
+	talloc_free(buf);
+err_close:
+	close(fd);
+	return -1;
+}
+
+static void iterate_parser_files(struct discover_context *ctx,
+		const struct parser *parser)
+{
+	const char * const *filename;
+	const char *path, *url;
+	unsigned int tempfile;
+
+	if (!parser->filenames)
+		return;
+
+	for (filename = parser->filenames; *filename; filename++) {
+		int rc, len;
+		char *buf;
+
+		url = resolve_path(ctx, *filename, ctx->device->device_path);
+		if (!url)
+			continue;
+
+		path = load_file(ctx, url, &tempfile);
+
+		if (!path)
+			continue;
+
+		rc = read_file(ctx, path, &buf, &len);
+		if (!rc) {
+			parser->parse(ctx, buf, len);
+			talloc_free(buf);
+		}
+
+		if (tempfile)
+			unlink(path);
+
+	}
+
+}
+
 void iterate_parsers(struct discover_context *ctx)
 {
 	int i;
-	unsigned int count = 0;
 
 	pb_log("trying parsers for %s\n", ctx->device->device->id);
 
 	for (i = 0; parsers[i]; i++) {
 		pb_log("\ttrying parser '%s'\n", parsers[i]->name);
-		count += parsers[i]->parse(ctx);
+		iterate_parser_files(ctx, parsers[i]);
 	}
-	if (!count)
-		pb_log("\tno boot_options found\n");
 }
 
 void parser_init(void)
diff --git a/discover/parser.h b/discover/parser.h
index c2f02d6..18c9963 100644
--- a/discover/parser.h
+++ b/discover/parser.h
@@ -6,7 +6,8 @@ struct discover_context;
 struct parser {
 	char			*name;
 	const char * const	*filenames;
-	int			(*parse)(struct discover_context *ctx);
+	int			(*parse)(struct discover_context *ctx,
+						char *buf, int len);
 };
 
 enum generic_icon_type {
diff --git a/discover/yaboot-parser.c b/discover/yaboot-parser.c
index 0477d38..d7a0a9f 100644
--- a/discover/yaboot-parser.c
+++ b/discover/yaboot-parser.c
@@ -287,11 +287,10 @@ static const char *yaboot_known_names[] = {
 	NULL
 };
 
-static int yaboot_parse(struct discover_context *dc)
+static int yaboot_parse(struct discover_context *dc, char *buf, int len)
 {
 	struct conf_context *conf;
 	struct yaboot_state *state;
-	int rc;
 
 	conf = talloc_zero(dc, struct conf_context);
 
@@ -301,7 +300,6 @@ static int yaboot_parse(struct discover_context *dc)
 	conf->dc = dc;
 	conf->global_options = yaboot_global_options,
 	conf_init_global_options(conf);
-	conf->conf_files = yaboot_conf_files,
 	conf->get_pair = conf_get_pair_equal;
 	conf->process_pair = yaboot_process_pair;
 	conf->finish = yaboot_finish;
@@ -314,10 +312,10 @@ static int yaboot_parse(struct discover_context *dc)
 	state->opt = talloc_zero(conf->dc->device, struct boot_option);
 	state->opt->boot_args = talloc_strdup(state->opt, "");
 
-	rc = conf_parse(conf);
+	conf_parse_buf(conf, buf, len);
 
 	talloc_free(conf);
-	return rc;
+	return 1;
 }
 
 struct parser __yaboot_parser = {