fix symlink handling in resolve_path

src/fs.c

@@ -24,6 +24,7 @@ static unsigned int fs_cwd_inode_ptr;
 static struct fs_file_description fs_file_descriptions[FS_MAX_OPEN_FD];
 
 static int extract_basename(char *path, char *name);
+static int read_symlink(int symlink_inode_ptr, char *path);
 
 
 static int read_block(unsigned int block_no, void *data)
@@ -953,21 +954,22 @@ static void resolve_path(struct resolved_path * const rp, const char * const ori
 		if (path[i] != '/') {
 			next_fname[next_fname_ptr] = path[i];
 			next_fname_ptr++;
-			continue;
 		}
 
-		// path[i] == '/', trying to change current directory
+		if ((path[i] != '/') && (i+1 < path_len))
+			continue;
 
 		if (!next_fname_ptr)
 			continue;
 
-		if (i+1 == path_len)
-			continue;
-
 		int res = find_fname_in_directory(current_inode_ptr, next_fname);
 		if (res < 0) {
-			pr_warn("directory '%s' does not exist\n", next_fname);
+			if (i+1 < path_len) {
+				pr_warn("parent '%s' does not exist\n", next_fname);
 				rp->parent_inode_ptr = -1;
+			}
+
+			rp->target_inode_ptr = -1;
 			break;
 		}
 
@@ -975,12 +977,53 @@ static void resolve_path(struct resolved_path * const rp, const char * const ori
 		read_block(read_inode_ptr(res), &d);
 
 		if (d.ftype == SYMLINK) {
+			if (i+1 < path_len) {
 				char symlink_path[FS_MAX_PATH_LEN+1];
 				int symlink_path_len = read_symlink(res, symlink_path);
 
 				if (symlink_path_len < 0) {
 					pr_warn("broken symlink\n");
 					rp->parent_inode_ptr = -1;
+					rp->target_inode_ptr = -1;
+					break;
+				}
+
+				if (symlink_path[0] == '/') {
+					memmove(&(path[symlink_path_len]), &(path[i+1]), path_len-i-1);
+					strcpy(path, &(symlink_path[1]));
+					path[symlink_path_len-1] = '/';
+					path_len = symlink_path_len + path_len - i - 1;
+					i = -1;
+
+					next_fname_ptr = 0;
+					strcpy(current_fname, "/");
+					memset(next_fname, 0, FS_MAX_FNAME_LEN);
+				} else {
+					memmove(&(path[symlink_path_len+1]), &(path[i+1]), path_len-i-1);
+					strcpy(path, symlink_path);
+					path[symlink_path_len] = '/';
+					path_len = symlink_path_len + path_len - i;
+					i = -1;
+
+					next_fname_ptr = 0;
+					strcpy(current_fname, next_fname);
+					memset(next_fname, 0, FS_MAX_FNAME_LEN);
+				}
+			} else {
+				if (!(params & FOLLOW_LAST_SYMLINK)) {
+					rp->target_inode_ptr = res;
+					strcpy(rp->parent_fname, current_fname);
+					strcpy(rp->target_fname, next_fname);
+					break;
+				}
+
+				char symlink_path[FS_MAX_PATH_LEN+1];
+				int symlink_path_len = read_symlink(res, symlink_path);
+
+				if (symlink_path_len < 0) {
+					pr_warn("broken symlink\n");
+					rp->parent_inode_ptr = -1;
+					rp->target_inode_ptr = -1;
 					break;
 				}
 
@@ -989,69 +1032,55 @@ static void resolve_path(struct resolved_path * const rp, const char * const ori
 					rp->target_inode_ptr = 0;
 					strcpy(rp->parent_fname, "/");
 					strcpy(rp->target_fname, "/");
-				return;
+					break;
 				}
 
 				if (symlink_path[0] == '/') {
-				res = 0;
+					strcpy(path, &(symlink_path[1]));
-				memmove(&(path[symlink_path_len]), &(path[i+1]), path_len-i-1);
+					path_len = symlink_path_len - 1;
-				path[symlink_path_len-1] = '/';
-				memcpy(path, &(symlink_path[1]), symlink_path_len-1);
-				path_len = symlink_path_len + path_len - i + 1;
 					i = -1;
-				strcpy(next_fname, "/");
+
+					next_fname_ptr = 0;
+					strcpy(current_fname, "/");
+					memset(next_fname, 0, FS_MAX_FNAME_LEN);
 				} else {
-				memmove(&(path[symlink_path_len+1]), &(path[i+1]), path_len-i-1);
+					strcpy(path, symlink_path);
-				path[symlink_path_len] = '/';
+					path_len = symlink_path_len;
-				memcpy(path, symlink_path, symlink_path_len);
-				path_len = symlink_path_len + path_len - i + 2;
 					i = -1;
-			}
-		} else if (d.ftype == REGULAR) {
-			pr_warn("'%s' is a regular file\n", next_fname);
-			rp->parent_inode_ptr = -1;
-			break;
-		} else if (d.ftype == DIRECTORY) {
-			pr("Found directory '%s'\n", next_fname);
-			current_inode_ptr = res;
-			rp->parent_inode_ptr = res;
-		}
 
 					next_fname_ptr = 0;
 					strcpy(current_fname, next_fname);
 					memset(next_fname, 0, FS_MAX_FNAME_LEN);
 				}
-
-	if (rp->parent_inode_ptr < 0) {
-		rp->target_inode_ptr = -1;
-		return;
 			}
-
+		} else if (d.ftype == REGULAR) {
-	strcpy(rp->parent_fname, current_fname);
+			if (i+1 < path_len) {
-
+				pr_warn("'%s': regular file not in the end of a path\n", next_fname);
-	{
+				rp->parent_inode_ptr = -1;
-		int res = find_fname_in_directory(current_inode_ptr, next_fname);
-		if (res < 0) {
-			pr_warn("target fname '%s' does not exist\n", next_fname);
 				rp->target_inode_ptr = -1;
-		}
+				break;
-
-		struct fs_inode i;
-		read_block(res, &i);
-
-		if (i.ftype == SYMLINK && (params & FOLLOW_LAST_SYMLINK))
-			struct 
-			/*
-			rp->target_inode_ptr = res;
-			strcpy(rp->target_fname, next_fname);
-			*/
 			} else {
 				rp->target_inode_ptr = res;
+				strcpy(rp->parent_fname, current_fname);
+				strcpy(rp->target_fname, next_fname);
+			}
+		} else if (d.ftype == DIRECTORY) {
+			if (i+1 < path_len) {
+				pr("Found directory '%s'\n", next_fname);
+				current_inode_ptr = res;
+				rp->parent_inode_ptr = res;
+
+				next_fname_ptr = 0;
+				strcpy(current_fname, next_fname);
+				memset(next_fname, 0, FS_MAX_FNAME_LEN);
+			} else {
+				rp->target_inode_ptr = res;
+				strcpy(rp->parent_fname, current_fname);
 				strcpy(rp->target_fname, next_fname);
 			}
 		}
 
-	return;
+	}
 }