From cfb76ff6eecec15636f182009cda50ea0c654c60 Mon Sep 17 00:00:00 2001
From: Evan Green <evangreen86@gmail.com>
Date: Fri, 7 Dec 2018 16:03:43 -0800
Subject: [PATCH] storage: Allow specifying the storage directory

Enable the specification of storage paths other than /boot, using
a new -o command line argument. Getoptify the command line arguments
for better processing.
---
 rmtfs.c   | 23 ++++++++++++++++++++---
 rmtfs.h   |  2 +-
 storage.c | 24 +++++++++++++++++-------
 3 files changed, 38 insertions(+), 11 deletions(-)

diff --git a/rmtfs.c b/rmtfs.c
index c190d17..aa8e09a 100644
--- a/rmtfs.c
+++ b/rmtfs.c
@@ -448,15 +448,32 @@ static int run_rmtfs(void)
 int main(int argc, char **argv)
 {
 	int ret;
+	int option;
+	const char *storage_root = NULL;
 
-	if (argc == 2 && strcmp(argv[1], "-v") == 0)
-		dbgprintf_enabled = true;
+	while ((option = getopt(argc, argv, "o:v")) != -1) {
+		switch (option) {
+		/* -o sets the directory where EFS images are stored. */
+		case 'o':
+			storage_root = optarg;
+			break;
+
+		/* -v is for verbose */
+		case 'v':
+			dbgprintf_enabled = 1;
+			break;
+
+		case '?':
+			fprintf(stderr, "Unknown option: -%c\n", option);
+			return 1;
+		}
+	}
 
 	rmem = rmtfs_mem_open();
 	if (!rmem)
 		return 1;
 
-	ret = storage_open();
+	ret = storage_open(storage_root);
 	if (ret) {
 		fprintf(stderr, "failed to initialize storage system\n");
 		goto close_rmtfs_mem;
diff --git a/rmtfs.h b/rmtfs.h
index fdd600c..7ab8733 100644
--- a/rmtfs.h
+++ b/rmtfs.h
@@ -23,7 +23,7 @@ void rmtfs_mem_free(struct rmtfs_mem *rmem);
 ssize_t rmtfs_mem_read(struct rmtfs_mem *rmem, unsigned long phys_address, void *buf, ssize_t len);
 ssize_t rmtfs_mem_write(struct rmtfs_mem *rmem, unsigned long phys_address, const void *buf, ssize_t len);
 
-int storage_open(void);
+int storage_open(const char *storage_root);
 int storage_get(unsigned node, const char *path);
 int storage_put(unsigned node, int caller_id);
 int storage_get_handle(unsigned node, int caller_id);
diff --git a/storage.c b/storage.c
index 09092a7..b1fa4d4 100644
--- a/storage.c
+++ b/storage.c
@@ -22,20 +22,25 @@ struct caller {
 	const struct partition *partition;
 };
 
+static const char *storage_dir = "/boot";
+
 static const struct partition partition_table[] = {
-	{ "/boot/modem_fs1", "/boot/modem_fs1" },
-	{ "/boot/modem_fs2", "/boot/modem_fs2" },
-	{ "/boot/modem_fsc", "/boot/modem_fsc" },
-	{ "/boot/modem_fsg", "/boot/modem_fsg" },
+	{ "/boot/modem_fs1", "modem_fs1" },
+	{ "/boot/modem_fs2", "modem_fs2" },
+	{ "/boot/modem_fsc", "modem_fsc" },
+	{ "/boot/modem_fsg", "modem_fsg" },
 	{}
 };
 
 static struct caller caller_handles[MAX_CALLERS];
 
-int storage_open(void)
+int storage_open(const char *storage_root)
 {
 	int i;
 
+	if (storage_root)
+		storage_dir = storage_root;
+
 	for (i = 0; i < MAX_CALLERS; i++) {
 		caller_handles[i].id = i;
 		caller_handles[i].fd = -1;
@@ -46,8 +51,10 @@ int storage_open(void)
 
 int storage_get(unsigned node, const char *path)
 {
+	char *fspath;
 	const struct partition *part;
 	struct caller *caller = NULL;
+	size_t pathlen;
 	int saved_errno;
 	int fd;
 	int i;
@@ -80,11 +87,14 @@ found:
 		return -EBUSY;
 	}
 
-	fd = open(part->actual, O_RDWR);
+	pathlen = strlen(storage_dir) + strlen(part->actual) + 2;
+	fspath = alloca(pathlen);
+	snprintf(fspath, pathlen, "%s/%s", storage_dir, part->actual);
+	fd = open(fspath, O_RDWR);
 	if (fd < 0) {
 		saved_errno = errno;
 		fprintf(stderr, "[storage] failed to open '%s' (requested '%s'): %s\n",
-				part->actual, part->path, strerror(saved_errno));
+				fspath, part->path, strerror(saved_errno));
 		return -saved_errno;
 	}