From 19fbebec161c749e5bfe440e4514e2bc2d2ac3d4 Mon Sep 17 00:00:00 2001
From: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Date: Wed, 19 Jun 2019 13:21:52 +0200
Subject: Cleanup fstree code

Replace default_$FIELD with a struct stat. Merge the rest of
add_node/add_file into mknode and add by path+stat.

Expose the mknode function and replace all the duplicated node pointer
arithmetic magic with a call to mknode.

Plus a generic cleanup by utlizing new util functions.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
---
 lib/fstree/fstree_from_dir.c | 174 ++++++++++++++++---------------------------
 1 file changed, 63 insertions(+), 111 deletions(-)

(limited to 'lib/fstree/fstree_from_dir.c')

diff --git a/lib/fstree/fstree_from_dir.c b/lib/fstree/fstree_from_dir.c
index fb906f1..ea1ebe9 100644
--- a/lib/fstree/fstree_from_dir.c
+++ b/lib/fstree/fstree_from_dir.c
@@ -7,55 +7,57 @@
 #include <unistd.h>
 #include <string.h>
 #include <stdlib.h>
+#include <assert.h>
 #include <stdio.h>
 #include <errno.h>
 #include <fcntl.h>
 
-static size_t path_size(tree_node_t *n)
+static char *get_file_path(tree_node_t *n, const char *name)
 {
-	size_t size = 0;
+	char *ptr, *new;
 
-	while (n != NULL) {
-		size += strlen(n->name) + 1;
-		n = n->parent;
+	if (n->parent == NULL) {
+		ptr = strdup(name);
+		if (ptr == NULL)
+			goto fail;
+		return ptr;
 	}
 
-	return size;
-}
+	ptr = fstree_get_path(n);
+	if (ptr == NULL)
+		goto fail;
 
-static char *print_path(char *ptr, tree_node_t *n)
-{
-	if (n->parent != NULL) {
-		ptr = print_path(ptr, n->parent);
-		*(ptr++) = '/';
-		strcpy(ptr, n->name);
-		return ptr + strlen(ptr);
-	}
+	assert(canonicalize_name(ptr) == 0);
+
+	new = realloc(ptr, strlen(ptr) + strlen(name) + 2);
+	if (new == NULL)
+		goto fail;
 
+	ptr = new;
+	strcat(ptr, "/");
+	strcat(ptr, name);
 	return ptr;
+fail:
+	perror("getting absolute file path");
+	free(ptr);
+	return NULL;
 }
 
-static int populate_dir(tree_node_t *root, int fd, size_t blocksize,
-			const char *rootdir)
+static int populate_dir(fstree_t *fs, tree_node_t *root)
 {
-	size_t size, blockcount;
+	char *extra = NULL;
 	struct dirent *ent;
 	struct stat sb;
 	tree_node_t *n;
-	ssize_t ret;
-	void *ptr;
 	DIR *dir;
-	int cfd;
 
-	dir = fdopendir(fd);
+	dir = opendir(".");
 	if (dir == NULL) {
-		perror("fdopendir");
-		close(fd);
+		perror("opendir");
 		return -1;
 	}
 
 	for (;;) {
-		n = NULL;
 		errno = 0;
 		ent = readdir(dir);
 
@@ -70,120 +72,70 @@ static int populate_dir(tree_node_t *root, int fd, size_t blocksize,
 		if (!strcmp(ent->d_name, "..") || !strcmp(ent->d_name, "."))
 			continue;
 
-		if (fstatat(fd, ent->d_name, &sb, AT_SYMLINK_NOFOLLOW)) {
+		if (fstatat(AT_FDCWD, ent->d_name, &sb, AT_SYMLINK_NOFOLLOW)) {
 			perror(ent->d_name);
 			goto fail;
 		}
 
-		size = sizeof(tree_node_t) + strlen(ent->d_name) + 1;
-
-		switch (sb.st_mode & S_IFMT) {
-		case S_IFLNK:
-			size += sb.st_size + 1;
-			break;
-		case S_IFREG:
-			blockcount = sb.st_size / blocksize + 1;
-
-			size += sizeof(file_info_t);
-			size += sizeof(uint32_t) * blockcount;
+		if (S_ISLNK(sb.st_mode)) {
+			extra = alloca(sb.st_size + 1);
+			if (extra == NULL)
+				goto fail_rdlink;
 
-			size += path_size(root) + strlen(ent->d_name) + 1;
-			size += strlen(rootdir) + 2;
-			break;
-		case S_IFDIR:
-			size += sizeof(dir_info_t);
-			break;
+			if (readlink(ent->d_name, extra, sb.st_size) < 0)
+				goto fail_rdlink;
+		} else if (S_ISREG(sb.st_mode)) {
+			extra = get_file_path(root, ent->d_name);
+			if (extra == NULL)
+				goto fail;
 		}
 
-		n = calloc(1, size);
+		n = fstree_mknode(fs, root, ent->d_name, strlen(ent->d_name),
+				  extra, &sb);
 		if (n == NULL) {
-			perror("allocating tree node");
+			perror("creating tree node");
 			goto fail;
 		}
 
-		n->uid = sb.st_uid;
-		n->gid = sb.st_gid;
-		n->mode = sb.st_mode;
-		n->parent = root;
-
-		ptr = n->payload;
-
-		switch (sb.st_mode & S_IFMT) {
-		case S_IFLNK:
-			ret = readlinkat(fd, ent->d_name, ptr, sb.st_size);
-			if (ret < 0) {
-				perror("readlink");
-				goto fail;
-			}
-
-			n->data.slink_target = ptr;
-			ptr = (char *)ptr + strlen(ptr) + 1;
-			break;
-		case S_IFBLK:
-		case S_IFCHR:
-			n->data.devno = sb.st_rdev;
-			break;
-		case S_IFDIR:
-			n->data.dir = ptr;
-			ptr = (char *)ptr + sizeof(dir_info_t);
-			break;
-		case S_IFREG:
-			n->data.file = ptr;
-			ptr = (char *)ptr + sizeof(file_info_t);
-			ptr = (char *)ptr + sizeof(uint32_t) * blockcount;
-
-			n->data.file->input_file = ptr;
-			n->data.file->size = sb.st_size;
-
-			strcpy(ptr, rootdir);
-			ptr = (char *)ptr + strlen(ptr);
-			ptr = print_path(ptr, root);
-
-			*((char*)ptr) = '/';
-			strcpy((char *)ptr + 1, ent->d_name);
-			ptr = (char *)ptr + strlen(ptr) + 1;
-			break;
-		}
-
-		n->name = ptr;
-		strcpy(ptr, ent->d_name);
-
-		n->next = root->data.dir->children;
-		root->data.dir->children = n;
+		free(extra);
+		extra = NULL;
 	}
 
+	closedir(dir);
+
 	for (n = root->data.dir->children; n != NULL; n = n->next) {
 		if (S_ISDIR(n->mode)) {
-			cfd = openat(fd, n->name, O_RDONLY | O_DIRECTORY);
-			if (cfd < 0) {
-				perror(n->name);
-				goto fail_dir;
-			}
+			if (pushd(n->name))
+				return -1;
 
-			if (populate_dir(n, cfd, blocksize, rootdir)) {
-				close(cfd);
-				goto fail_dir;
-			}
+			if (populate_dir(fs, n))
+				return -1;
+
+			if (popd())
+				return -1;
 		}
 	}
 
-	closedir(dir);
 	return 0;
+fail_rdlink:
+	perror("readlink");
 fail:
-	free(n);
-fail_dir:
 	closedir(dir);
+	free(extra);
 	return -1;
 }
 
 int fstree_from_dir(fstree_t *fs, const char *path)
 {
-	int fd = open(path, O_RDONLY | O_DIRECTORY);
+	int ret;
 
-	if (fd < 0) {
-		perror(path);
+	if (pushd(path))
 		return -1;
-	}
 
-	return populate_dir(fs->root, fd, fs->block_size, path);
+	ret = populate_dir(fs, fs->root);
+
+	if (popd())
+		ret = -1;
+
+	return ret;
 }
-- 
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