sandbox: Add a way of obtaining directory listings

This implementation uses opendir()/readdir() to access the directory
information and then puts it in a linked list for the caller's use.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@ti.com>

arch/sandbox/cpu/os.c

@@ -19,10 +19,13 @@
  * MA 02111-1307 USA
  */
 
+#include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <getopt.h>
+#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <termios.h>
 #include <time.h>
 #include <unistd.h>
@@ -261,3 +264,101 @@ int os_parse_args(struct sandbox_state *state, int argc, char *argv[])
 
 	return 0;
 }
+
+void os_dirent_free(struct os_dirent_node *node)
+{
+	struct os_dirent_node *next;
+
+	while (node) {
+		next = node->next;
+		free(node);
+		node = next;
+	}
+}
+
+int os_dirent_ls(const char *dirname, struct os_dirent_node **headp)
+{
+	struct dirent entry, *result;
+	struct os_dirent_node *head, *node, *next;
+	struct stat buf;
+	DIR *dir;
+	int ret;
+	char *fname;
+	int len;
+
+	*headp = NULL;
+	dir = opendir(dirname);
+	if (!dir)
+		return -1;
+
+	/* Create a buffer for the maximum filename length */
+	len = sizeof(entry.d_name) + strlen(dirname) + 2;
+	fname = malloc(len);
+	if (!fname) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	for (node = head = NULL;; node = next) {
+		ret = readdir_r(dir, &entry, &result);
+		if (ret || !result)
+			break;
+		next = malloc(sizeof(*node) + strlen(entry.d_name) + 1);
+		if (!next) {
+			os_dirent_free(head);
+			ret = -ENOMEM;
+			goto done;
+		}
+		strcpy(next->name, entry.d_name);
+		switch (entry.d_type) {
+		case DT_REG:
+			next->type = OS_FILET_REG;
+			break;
+		case DT_DIR:
+			next->type = OS_FILET_DIR;
+			break;
+		case DT_LNK:
+			next->type = OS_FILET_LNK;
+			break;
+		}
+		next->size = 0;
+		snprintf(fname, len, "%s/%s", dirname, next->name);
+		if (!stat(fname, &buf))
+			next->size = buf.st_size;
+		if (node)
+			node->next = next;
+		if (!head)
+			head = node;
+	}
+	*headp = head;
+
+done:
+	closedir(dir);
+	return ret;
+}
+
+const char *os_dirent_typename[OS_FILET_COUNT] = {
+	"   ",
+	"SYM",
+	"DIR",
+	"???",
+};
+
+const char *os_dirent_get_typename(enum os_dirent_t type)
+{
+	if (type >= 0 && type < OS_FILET_COUNT)
+		return os_dirent_typename[type];
+
+	return os_dirent_typename[OS_FILET_UNKNOWN];
+}
+
+ssize_t os_get_filesize(const char *fname)
+{
+	struct stat buf;
+	int ret;
+
+	ret = stat(fname, &buf);
+	if (ret)
+		return ret;
+	return buf.st_size;
+}

include/os.h

@@ -146,4 +146,52 @@ u64 os_get_nsec(void);
  */
 int os_parse_args(struct sandbox_state *state, int argc, char *argv[]);
 
+/*
+ * Types of directory entry that we support. See also os_dirent_typename in
+ * the C file.
+ */
+enum os_dirent_t {
+	OS_FILET_REG,		/* Regular file */
+	OS_FILET_LNK,		/* Symbolic link */
+	OS_FILET_DIR,		/* Directory */
+	OS_FILET_UNKNOWN,	/* Something else */
+
+	OS_FILET_COUNT,
+};
+
+/** A directory entry node, containing information about a single dirent */
+struct os_dirent_node {
+	struct os_dirent_node *next;	/* Pointer to next node, or NULL */
+	ulong size;			/* Size of file in bytes */
+	enum os_dirent_t type;		/* Type of entry */
+	char name[0];			/* Name of entry */
+};
+
+/**
+ * Get a directionry listing
+ *
+ * This allocates and returns a linked list containing the directory listing.
+ *
+ * @param dirname	Directory to examine
+ * @param headp		Returns pointer to head of linked list, or NULL if none
+ * @return 0 if ok, -ve on error
+ */
+int os_dirent_ls(const char *dirname, struct os_dirent_node **headp);
+
+/**
+ * Get the name of a directory entry type
+ *
+ * @param type		Type to cehck
+ * @return string containing the name of that type, or "???" if none/invalid
+ */
+const char *os_dirent_get_typename(enum os_dirent_t type);
+
+/**
+ * Get the size of a file
+ *
+ * @param fname		Filename to check
+ * @return size of file, or -1 if an error ocurred
+ */
+ssize_t os_get_filesize(const char *fname);
+
 #endif