Added backing signatures

src/backing.c

@@ -1,5 +1,7 @@
 #include "backing.h"
 
+#include "entry.h"
+
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
@@ -61,3 +63,4 @@ Result backing_exists(const char* backing_id, bool* out_exists) {
 
 	return SUCCESS;
 }
+

src/backing.h

@@ -9,19 +9,49 @@
 #define BACKING_POOL_DIR "/var/lib/sandbox/backings"
 #define MAX_BACKING_LENGTH 256
 
-/// @brief Checks whether the given backing id is valid.
-/// @param backing_id The backing id to check.
-/// @return True if the backing id is valid, false otherwise.
+typedef struct {
+	DiskInfo disk_info;
+} BackingInfo;
+
+/// @brief Checks whether the given backing disk id is valid.
+/// @param backing_id The backing disk id to check.
+/// @return True if the backing disk id is valid, false otherwise.
 bool is_valid_backing_id(const char* backing_id);
 
-/// @brief Gets the path of the given backing.
-/// @param backing_id The backing id.
+/// @brief Gets the path of the given backing disk.
+/// @param backing_id The backing disk id.
 /// @param out_path The pointer to the output path string. The caller is responsible for freeing the memory.
 /// @return The result of the operation.
 Result get_backing_path(const char* backing_id, char** out_path);
 
-/// @brief Checks whether the given backing exists in the pool.
-/// @param backing_id The backing id.
+/// @brief Checks whether the given backing disk exists in the pool.
+/// @param backing_id The backing disk id.
 /// @param out_exists The pointer to the output boolean.
 /// @return The result of the operation.
 Result backing_exists(const char* backing_id, bool* out_exists);
+
+/// @brief Adds a backing disk to the pool from an entry.
+/// @param backing_id The backing disk id.
+/// @param entry_id The entry id.
+/// @return The result of the operation.
+Result add_backing_from_entry(const char* backing_id, const char* entry_id);
+
+/// @brief Removes a backing disk from the pool, and removes any backing disks that uses it.
+/// @param backing_id The backing disk id.
+/// @return The result of the operation.
+Result remove_backing(const char* backing_id);
+
+/// @brief Lists the backing disks in the pool.
+/// @param out_backings The pointer to the null-terminated array of backing disk ids. The caller is responsible for freeing the memory of the array and its elements.
+/// @return The result of the operation.
+Result list_backings(char*** out_backings, size_t* out_count);
+
+/// @brief Gathers information about a backing disk.
+/// @param backing_id The backing disk id.
+/// @param out_info The information about the backing disk.
+/// @return The result of the operation.
+Result get_backing_info(const char* backing_id, BackingInfo* out_info);
+
+/// @brief Frees the resources used by the given backing disk information.
+/// @param info The backing disk information to free.
+void free_backing_info(BackingInfo* info);

src/entry.h

@@ -85,7 +85,7 @@ Result add_automatic_entry(const char* entry_id);
 Result remove_entry(const char* entry_id);
 
 /// @brief Lists the entries in the pool.
-/// @param out_entries The pointer to the output entries string. The caller is responsible for freeing the memory of the strings and the array.
+/// @param out_entries The pointer to the null-terminated array of entry ids. The caller is responsible for freeing the memory of the array and its elements.
 /// @return The result of the operation.
 Result list_entries(char*** out_entries);
 

src/utils.c

@@ -343,6 +343,60 @@ Result write_file(const char* path, const char* string) {
 	return result;
 }
 
+Result copy_file(const char* src_path, const char* dst_path, mode_t mode) {
+	// Open the source file
+	int src_fd = open(src_path, O_RDONLY);
+	if (src_fd == -1) {
+		log_message(LOG_LEVEL_ERROR, "Failed to open the source file '%s' (%s).", src_path, strerror(errno));
+		return FAILURE;
+	}
+
+	// Open the destination file
+	int dst_fd = open(dst_path, O_WRONLY | O_CREAT | O_TRUNC, mode);
+	if (dst_fd == -1) {
+		log_message(LOG_LEVEL_ERROR, "Failed to open the destination file '%s' (%s).", dst_path, strerror(errno));
+
+		close(src_fd);
+		return FAILURE;
+	}
+
+	// Copy the file
+	char buffer[4096];
+	ssize_t bytes_read;
+
+	while ((bytes_read = read(src_fd, buffer, sizeof(buffer))) > 0) {
+		ssize_t bytes_written = 0;
+
+		while (bytes_written < bytes_read) {
+			ssize_t result = write(dst_fd, buffer + bytes_written, bytes_read - bytes_written);
+			if (result == -1) {
+				log_message(LOG_LEVEL_ERROR, "Failed to write to the destination file '%s' (%s).", dst_path, strerror(errno));
+
+				close(src_fd);
+				close(dst_fd);
+				return FAILURE;
+			}
+
+			bytes_written += result;
+		}
+	}
+
+	// Check if an error occurred
+	if (bytes_read == -1) {
+		log_message(LOG_LEVEL_ERROR, "Failed to read from the source file '%s' (%s).", src_path, strerror(errno));
+
+		close(src_fd);
+		close(dst_fd);
+		return FAILURE;
+	}
+
+	// Close the files
+	close(src_fd);
+	close(dst_fd);
+
+	return SUCCESS;
+}
+
 Result format_size(uint64_t size, char** out_string) {
 	*out_string = NULL;
 

src/utils.h

@@ -2,6 +2,7 @@
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <sys/types.h>
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 
@@ -69,6 +70,13 @@ Result write_fd(int fd, const char* string);
 /// @return The result of the operation.
 Result write_file(const char* path, const char* string);
 
+/// @brief Copies a file.
+/// @param src_path The path of the source file.
+/// @param dst_path The path of the destination file.
+/// @param mode The mode of the destination file.
+/// @return The result of the operation.
+Result copy_file(const char* src_path, const char* dst_path, mode_t mode);
+
 /// @brief Converts a size in bytes to a human-readable string.
 /// @param size The size in bytes.
 /// @param out_string The pointer to the output string. The caller is responsible for freeing the memory.