Merge branch 'for-next/link'

3 files changed, 335 insertions, 41 deletions

diff --git a/fs/fs.c b/fs/fs.c
index 8ab1a3a7ef..38917bf72b 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -26,6 +26,7 @@
 #include <errno.h>
 #include <malloc.h>
 #include <linux/stat.h>
+#include <linux/err.h>
 #include <fcntl.h>
 #include <xfuncs.h>
 #include <init.h>
@@ -111,6 +112,61 @@ static int init_cwd(void)
 
 postcore_initcall(init_cwd);
 
+char *normalise_link(const char *pathname, const char *symlink)
+{
+	const char *buf = symlink;
+	char *path_free, *path;
+	char *absolute_path;
+	int point = 0;
+	int dir = 1;
+	int len;
+
+	if (symlink[0] == '/')
+		return strdup(symlink);
+
+	while (*buf == '.' || *buf == '/') {
+		if (*buf == '.') {
+			point++;
+		} else if (*buf == '/') {
+			point = 0;
+			dir++;
+		}
+		if (point > 2) {
+			buf -= 2;
+			break;
+		}
+		buf++;
+	}
+
+	path = path_free = strdup(pathname);
+	if (!path)
+		return NULL;
+
+	while(dir) {
+		path = dirname(path);
+		dir--;
+	}
+
+	len = strlen(buf) + strlen(path) + 1;
+	if (buf[0] != '/')
+		len++;
+
+	absolute_path = calloc(sizeof(char), len);
+
+	if (!absolute_path)
+		goto out;
+
+	strcat(absolute_path, path);
+	if (buf[0] != '/')
+		strcat(absolute_path, "/");
+	strcat(absolute_path, buf);
+
+out:
+	free(path_free);
+
+	return absolute_path;
+}
+
 char *normalise_path(const char *pathname)
 {
 	char *path = xzalloc(strlen(pathname) + strlen(cwd) + 2);
@@ -187,6 +243,15 @@ static struct fs_device_d *get_fsdevice_by_path(const char *path)
 	return fs_dev_root;
 }
 
+char *get_mounted_path(const char *path)
+{
+	struct fs_device_d *fdev;
+
+	fdev = get_fsdevice_by_path(path);
+
+	return fdev->path;
+}
+
 static FILE files[MAX_FILES];
 
 static FILE *get_file(void)
@@ -392,7 +457,7 @@ static int path_check_prereq(const char *path, unsigned int flags)
 	unsigned int m;
 	int ret = 0;
 
-	if (stat(path, &s)) {
+	if (lstat(path, &s)) {
 		if (flags & S_UB_DOES_NOT_EXIST)
 			goto out;
 		ret = -ENOENT;
@@ -434,7 +499,7 @@ static int parent_check_directory(const char *path)
 	int ret;
 	char *dir = dirname(xstrdup(path));
 
-	ret = stat(dir, &s);
+	ret = lstat(dir, &s);
 
 	free(dir);
 
@@ -512,18 +577,61 @@ out:
 }
 EXPORT_SYMBOL(unlink);
 
+static char *realfile(const char *pathname, struct stat *s)
+{
+	char *path = normalise_path(pathname);
+	int ret;
+
+	ret = lstat(path, s);
+	if (ret)
+		goto out;
+
+	if (S_ISLNK(s->st_mode)) {
+		char tmp[PATH_MAX];
+		char *new_path;
+
+		memset(tmp, 0, PATH_MAX);
+
+		ret = readlink(path, tmp, PATH_MAX - 1);
+		if (ret < 0)
+			goto out;
+
+		new_path = normalise_link(path, tmp);
+		free(path);
+		if (!new_path)
+			return ERR_PTR(-ENOMEM);
+		path = new_path;
+
+		ret = lstat(path, s);
+	}
+
+	if (!ret)
+		return path;
+
+out:
+	free(path);
+	return ERR_PTR(ret);
+}
+
 int open(const char *pathname, int flags, ...)
 {
 	struct fs_device_d *fsdev;
 	struct fs_driver_d *fsdrv;
 	FILE *f;
-	int exist_err;
+	int exist_err = 0;
 	struct stat s;
-	char *path = normalise_path(pathname);
-	char *freep = path;
+	char *path;
+	char *freep;
 	int ret;
 
-	exist_err = stat(path, &s);
+	path = realfile(pathname, &s);
+
+	if (IS_ERR(path)) {
+		exist_err = PTR_ERR(path);
+		path = normalise_path(pathname);
+	}
+
+	freep = path;
 
 	if (!exist_err && S_ISDIR(s.st_mode)) {
 		ret = -EISDIR;
@@ -890,6 +998,94 @@ int close(int fd)
 }
 EXPORT_SYMBOL(close);
 
+int readlink(const char *pathname, char *buf, size_t bufsiz)
+{
+	struct fs_driver_d *fsdrv;
+	struct fs_device_d *fsdev;
+	char *p = normalise_path(pathname);
+	char *freep = p;
+	int ret;
+
+	ret = path_check_prereq(pathname, S_IFLNK);
+	if (ret)
+		goto out;
+
+	fsdev = get_fs_device_and_root_path(&p);
+	if (!fsdev) {
+		ret = -ENODEV;
+		goto out;
+	}
+	fsdrv = fsdev->driver;
+
+	if (fsdrv->readlink)
+		ret = fsdrv->readlink(&fsdev->dev, p, buf, bufsiz);
+	else
+		ret = -ENOSYS;
+
+	if (ret)
+		goto out;
+
+out:
+	free(freep);
+
+	if (ret)
+		errno = -ret;
+
+	return ret;
+}
+EXPORT_SYMBOL(readlink);
+
+int symlink(const char *pathname, const char *newpath)
+{
+	struct fs_driver_d *fsdrv;
+	struct fs_device_d *fsdev;
+	char *p;
+	char *freep = normalise_path(pathname);
+	int ret;
+	struct stat s;
+
+	if (!freep)
+		return -ENOMEM;
+
+	if (!stat(freep, &s) && S_ISDIR(s.st_mode)) {
+		ret = -ENOSYS;
+		goto out;
+	}
+
+	free(freep);
+	freep = p = normalise_path(newpath);
+
+	if (!p)
+		return -ENOMEM;
+
+	ret = lstat(p, &s);
+	if (!ret) {
+		ret = -EEXIST;
+		goto out;
+	}
+
+	fsdev = get_fs_device_and_root_path(&p);
+	if (!fsdev) {
+		ret = -ENODEV;
+		goto out;
+	}
+	fsdrv = fsdev->driver;
+
+	if (fsdrv->symlink) {
+		ret = fsdrv->symlink(&fsdev->dev, pathname, p);
+	} else {
+		ret = -EPERM;
+	}
+
+out:
+	free(freep);
+	if (ret)
+		errno = -ret;
+
+	return ret;
+}
+EXPORT_SYMBOL(symlink);
+
 static int fs_match(struct device_d *dev, struct driver_d *drv)
 {
 	return strcmp(dev->name, drv->name) ? -1 : 0;
@@ -1160,6 +1356,19 @@ EXPORT_SYMBOL(closedir);
 
 int stat(const char *filename, struct stat *s)
 {
+	char *f;
+
+	f = realfile(filename, s);
+	if (IS_ERR(f))
+		return PTR_ERR(f);
+
+	free(f);
+	return 0;
+}
+EXPORT_SYMBOL(stat);
+
+int lstat(const char *filename, struct stat *s)
+{
 	struct device_d *dev;
 	struct fs_driver_d *fsdrv;
 	struct fs_device_d *fsdev;
@@ -1197,7 +1406,7 @@ out:
 
 	return ret;
 }
-EXPORT_SYMBOL(stat);
+EXPORT_SYMBOL(lstat);
 
 int mkdir (const char *pathname, mode_t mode)
 {
@@ -1244,6 +1453,12 @@ int rmdir (const char *pathname)
 	char *freep = p;
 	int ret;
 
+	ret = path_check_prereq(pathname, S_IFLNK);
+	if (!ret) {
+		ret = -ENOTDIR;
+		goto out;
+	}
+
 	ret = path_check_prereq(pathname, S_IFDIR | S_UB_IS_EMPTY);
 	if (ret)
 		goto out;
diff --git a/fs/nfs.c b/fs/nfs.c
index 79e667f489..4a880cd302 100644
--- a/fs/nfs.c
+++ b/fs/nfs.c
@@ -605,34 +605,6 @@ static int nfs_read_req(struct file_priv *priv, int offset, int readlen)
 	return 0;
 }
 
-#if 0
-static int nfs_readlink_reply(unsigned char *pkt, unsigned len)
-{
-	uint32_t *data;
-	char *path;
-	int rlen;
-//	int ret;
-
-	data = (uint32_t *)(pkt + sizeof(struct rpc_reply));
-
-	data++;
-
-	rlen = ntohl(net_read_uint32(data)); /* new path length */
-
-	data++;
-	path = (char *)data;
-
-	if (*path != '/') {
-		strcat(nfs_path, "/");
-		strncat(nfs_path, path, rlen);
-	} else {
-		memcpy(nfs_path, path, rlen);
-		nfs_path[rlen] = 0;
-	}
-	return 0;
-}
-#endif
-
 static void nfs_handler(void *ctx, char *packet, unsigned len)
 {
 	char *pkt = net_eth_to_udp_payload(packet);
@@ -742,6 +714,63 @@ static struct file_priv *nfs_do_stat(struct device_d *dev, const char *filename,
 	return priv;
 }
 
+static int nfs_readlink_req(struct file_priv *priv, char* buf, size_t size)
+{
+	uint32_t data[1024];
+	uint32_t *p;
+	int len;
+	int ret;
+	char *path;
+	uint32_t *filedata;
+
+	p = &(data[0]);
+	p = rpc_add_credentials(p);
+
+	memcpy(p, priv->filefh, NFS_FHSIZE);
+	p += (NFS_FHSIZE / 4);
+
+	len = p - &(data[0]);
+
+	ret = rpc_req(priv->npriv, PROG_NFS, NFS_READLINK, data, len);
+	if (ret)
+		return ret;
+
+	filedata = nfs_packet + sizeof(struct rpc_reply);
+	filedata++;
+
+	len = ntohl(net_read_uint32(filedata)); /* new path length */
+	filedata++;
+
+	path = (char *)filedata;
+
+	if (len > size)
+		len = size;
+
+	memcpy(buf, path, len);
+
+	return 0;
+}
+
+static int nfs_readlink(struct device_d *dev, const char *filename,
+			char *realname, size_t size)
+{
+	struct file_priv *priv;
+	int ret;
+	struct stat s;
+
+	priv = nfs_do_stat(dev, filename, &s);
+	if (IS_ERR(priv))
+		return PTR_ERR(priv);
+
+	ret = nfs_readlink_req(priv, realname, size);
+	if (ret) {
+		nfs_do_close(priv);
+		return ret;
+	}
+
+	return 0;
+}
+
 static int nfs_open(struct device_d *dev, FILE *file, const char *filename)
 {
 	struct file_priv *priv;
@@ -1039,6 +1068,7 @@ static struct fs_driver_d nfs_driver = {
 	.rmdir     = nfs_rmdir,
 	.write     = nfs_write,
 	.truncate  = nfs_truncate,
+	.readlink  = nfs_readlink,
 	.flags     = 0,
 	.drv = {
 		.probe  = nfs_probe,
diff --git a/fs/ramfs.c b/fs/ramfs.c
index 91d06b8d3a..8f3b936685 100644
--- a/fs/ramfs.c
+++ b/fs/ramfs.c
@@ -42,6 +42,7 @@ struct ramfs_inode {
 	struct ramfs_inode *parent;
 	struct ramfs_inode *next;
 	struct ramfs_inode *child;
+	char *symlink;
 	ulong mode;
 
 	struct handle_d *handle;
@@ -176,6 +177,7 @@ static void ramfs_put_inode(struct ramfs_inode *node)
 		data = tmp;
 	}
 
+	free(node->symlink);
 	free(node->name);
 	free(node);
 }
@@ -212,18 +214,38 @@ static struct ramfs_inode* node_insert(struct ramfs_inode *parent_node, const ch
 
 /* ---------------------------------------------------------------*/
 
-static int ramfs_create(struct device_d *dev, const char *pathname, mode_t mode)
+static int __ramfs_create(struct device_d *dev, const char *pathname,
+			  mode_t mode, const char *symlink)
 {
 	struct ramfs_priv *priv = dev->priv;
 	struct ramfs_inode *node;
 	char *file;
+	char *__symlink = NULL;
 
 	node = rlookup_parent(priv, pathname, &file);
-	if (node) {
-		node_insert(node, file, mode);
-		return 0;
+	if (!node)
+		return -ENOENT;
+
+	if (symlink) {
+		__symlink = strdup(symlink);
+		if (!__symlink)
+			return -ENOMEM;
 	}
-	return -ENOENT;
+
+	node = node_insert(node, file, mode);
+	if (!node) {
+		free(__symlink);
+		return -ENOMEM;
+	}
+
+	node->symlink = __symlink;
+
+	return 0;
+}
+
+static int ramfs_create(struct device_d *dev, const char *pathname, mode_t mode)
+{
+	return __ramfs_create(dev, pathname, mode, NULL);
 }
 
 static int ramfs_unlink(struct device_d *dev, const char *pathname)
@@ -532,12 +554,37 @@ static int ramfs_stat(struct device_d *dev, const char *filename, struct stat *s
 	if (!node)
 		return -ENOENT;
 
-	s->st_size = node->size;
+	s->st_size = node->symlink ? strlen(node->symlink) : node->size;
 	s->st_mode = node->mode;
 
 	return 0;
 }
 
+static int ramfs_symlink(struct device_d *dev, const char *pathname,
+		       const char *newpath)
+{
+	mode_t mode = S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
+
+	return __ramfs_create(dev, newpath, mode, pathname);
+}
+
+static int ramfs_readlink(struct device_d *dev, const char *pathname,
+			char *buf, size_t bufsiz)
+{
+	struct ramfs_priv *priv = dev->priv;
+	struct ramfs_inode *node = rlookup(priv, pathname);
+	int len;
+
+	if (!node || !node->symlink)
+		return -ENOENT;
+
+	len = min(bufsiz, strlen(node->symlink));
+
+	memcpy(buf, node->symlink, len);
+
+	return 0;
+}
+
 static int ramfs_probe(struct device_d *dev)
 {
 	struct ramfs_inode *n;
@@ -584,6 +631,8 @@ static struct fs_driver_d ramfs_driver = {
 	.readdir   = ramfs_readdir,
 	.closedir  = ramfs_closedir,
 	.stat      = ramfs_stat,
+	.symlink   = ramfs_symlink,
+	.readlink  = ramfs_readlink,
 	.flags     = FS_DRIVER_NO_DEV,
 	.drv = {
 		.probe  = ramfs_probe,