summaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/fileio.cpp178
1 files changed, 159 insertions, 19 deletions
diff --git a/src/fileio.cpp b/src/fileio.cpp
index 09636640c..3b9772ff1 100644
--- a/src/fileio.cpp
+++ b/src/fileio.cpp
@@ -223,6 +223,9 @@ const char *_searchpaths[NUM_SEARCHPATHS];
TarList _tar_list;
TarFileList _tar_filelist;
+typedef std::map<std::string, std::string> TarLinkList;
+static TarLinkList _tar_linklist; ///< List of directory links
+
/**
* Check whether the given file exists
* @param filename the file to try for existance
@@ -357,11 +360,31 @@ FILE *FioFOpenFile(const char *filename, const char *mode, Subdirectory subdir,
/* We can only use .tar in case of data-dir, and read-mode */
if (f == NULL && subdir == DATA_DIR && mode[0] == 'r') {
+ static const uint MAX_RESOLVED_LENGTH = 2 * (100 + 100 + 155) + 1; // Enough space to hold two filenames plus link. See 'TarHeader'.
+ char resolved_name[MAX_RESOLVED_LENGTH];
+
/* Filenames in tars are always forced to be lowercase */
- char *lcfilename = strdup(filename);
- strtolower(lcfilename);
- TarFileList::iterator it = _tar_filelist.find(lcfilename);
- free(lcfilename);
+ strcpy(resolved_name, filename);
+ strtolower(resolved_name);
+
+ uint resolved_len = strlen(resolved_name);
+
+ /* Resolve ONE directory link */
+ for (TarLinkList::iterator link = _tar_linklist.begin(); link != _tar_linklist.end(); link++) {
+ const std::string &src = link->first;
+ uint len = src.length();
+ if (resolved_len >= len && resolved_name[len - 1] == PATHSEPCHAR && src.compare(0, len, resolved_name, len) == 0) {
+ /* Apply link */
+ char resolved_name2[MAX_RESOLVED_LENGTH];
+ const std::string &dest = link->second;
+ strcpy(resolved_name2, &(resolved_name[len]));
+ strcpy(resolved_name, dest.c_str());
+ strcpy(&(resolved_name[dest.length()]), resolved_name2);
+ break; // Only resolve one level
+ }
+ }
+
+ TarFileList::iterator it = _tar_filelist.find(resolved_name);
if (it != _tar_filelist.end()) {
f = FioFOpenFileTar(&((*it).second), filesize);
}
@@ -443,6 +466,22 @@ char *BuildWithFullPath(const char *dir)
return dest;
}
+/**
+ * Simplify filenames from tars.
+ * Replace '/' by PATHSEPCHAR, and force 'name' to lowercase.
+ * @param name Filename to process.
+ */
+static void SimplifyFileName(char *name)
+{
+ /* Force lowercase */
+ strtolower(name);
+
+ /* Tar-files always have '/' path-seperator, but we want our PATHSEPCHAR */
+#if (PATHSEPCHAR != '/')
+ for (char *n = name; *n != '\0'; n++) if (*n == '/') *n = PATHSEPCHAR;
+#endif
+}
+
static bool TarListAddFile(const char *filename)
{
/* The TAR-header, repeated for every file */
@@ -478,9 +517,13 @@ static bool TarListAddFile(const char *filename)
tar_entry->filename = strdup(filename);
_tar_list.insert(TarList::value_type(filename, tar_entry));
+ TarLinkList links; ///< Temporary list to collect links
+
TarHeader th;
char buf[sizeof(th.name) + 1], *end;
char name[sizeof(th.prefix) + 1 + sizeof(th.name) + 1];
+ char link[sizeof(th.linkname) + 1];
+ char dest[sizeof(th.prefix) + 1 + sizeof(th.name) + 1 + 1 + sizeof(th.linkname) + 1];
size_t num = 0, pos = 0;
/* Make a char of 512 empty bytes */
@@ -522,24 +565,95 @@ static bool TarListAddFile(const char *filename)
buf[sizeof(th.size)] = '\0';
int skip = strtol(buf, &end, 8);
- /* 0 byte sized files can be skipped (dirs, symlinks, ..) */
- if (skip == 0) continue;
+ switch (th.typeflag) {
+ case '\0':
+ case '0': { // regular file
+ /* Ignore empty files */
+ if (skip == 0) break;
- /* Store this entry in the list */
- TarFileListEntry entry;
- entry.tar = tar_entry;
- entry.size = skip;
- entry.position = pos;
- /* Force lowercase */
- strtolower(name);
+ if (strlen(name) == 0) break;
- /* Tar-files always have '/' path-seperator, but we want our PATHSEPCHAR */
-#if (PATHSEPCHAR != '/')
- for (char *n = name; *n != '\0'; n++) if (*n == '/') *n = PATHSEPCHAR;
-#endif
+ /* Store this entry in the list */
+ TarFileListEntry entry;
+ entry.tar = tar_entry;
+ entry.size = skip;
+ entry.position = pos;
+
+ /* Convert to lowercase and our PATHSEPCHAR */
+ SimplifyFileName(name);
+
+ DEBUG(misc, 6, "Found file in tar: %s (%d bytes, %d offset)", name, skip, pos);
+ if (_tar_filelist.insert(TarFileList::value_type(name, entry)).second) num++;
- DEBUG(misc, 6, "Found file in tar: %s (%d bytes, %d offset)", name, skip, pos);
- if (_tar_filelist.insert(TarFileList::value_type(name, entry)).second) num++;
+ break;
+ }
+
+ case '1': // hard links
+ case '2': { // symbolic links
+ /* Copy the destination of the link in a safe way at the end of 'linkname' */
+ memcpy(link, th.linkname, sizeof(th.linkname));
+ link[sizeof(th.linkname)] = '\0';
+
+ if (strlen(name) == 0 || strlen(link) == 0) break;
+
+ /* Convert to lowercase and our PATHSEPCHAR */
+ SimplifyFileName(name);
+ SimplifyFileName(link);
+
+ /* Only allow relative links */
+ if (link[0] == PATHSEPCHAR) {
+ DEBUG(misc, 1, "Ignoring absolute link in tar: %s -> %s", name, link);
+ break;
+ }
+
+ /* Process relative path.
+ * Note: The destination of links must not contain any directory-links. */
+ strcpy(dest, name);
+ char *destpos = strrchr(dest, PATHSEPCHAR);
+ if (destpos == NULL) destpos = dest;
+ *destpos = '\0';
+
+ char *pos = link;
+ while (*pos != '\0') {
+ char *next = strchr(link, PATHSEPCHAR);
+ if (next == NULL) next = pos + strlen(pos);
+
+ /* Skip '.' (current dir) */
+ if (next != pos + 1 || pos[0] != '.') {
+ if (next == pos + 2 && pos[0] == '.' && pos[1] == '.') {
+ /* level up */
+ if (dest[0] == '\0') {
+ DEBUG(misc, 1, "Ignoring link pointing outside of data directory: %s -> %s", name, link);
+ break;
+ }
+
+ /* Truncate 'dest' after last PATHSEPCHAR.
+ * This assumes, that the truncated part is a real directory and not a link */
+ destpos = strrchr(dest, PATHSEPCHAR);
+ if (destpos == NULL) destpos = dest;
+ } else {
+ /* Append at end of 'dest' */
+ if (destpos != dest) *(destpos++) = PATHSEPCHAR;
+ strncpy(destpos, pos, next - pos);
+ destpos += next - pos;
+ }
+ *destpos = '\0';
+ }
+
+ pos = next;
+ }
+
+ /* Store links in temporary list */
+ DEBUG(misc, 6, "Found link in tar: %s -> %s", name, dest);
+ links.insert(TarLinkList::value_type(name, dest));
+
+ break;
+ }
+
+ default:
+ /* Ignore other types */
+ break;
+ }
/* Skip to the next block.. */
skip = Align(skip, 512);
@@ -550,6 +664,32 @@ static bool TarListAddFile(const char *filename)
DEBUG(misc, 1, "Found tar '%s' with %d new files", filename, num);
fclose(f);
+ /* Resolve file links and store directory links.
+ * We restrict usage of links to two cases:
+ * 1) Links to directories:
+ * Both the source path and the destination path must NOT contain any further links.
+ * When resolving files at most one directory link is resolved.
+ * 2) Links to files:
+ * The destination path must NOT contain any links.
+ * The source path may contain one directory link.
+ */
+ for (TarLinkList::iterator link = links.begin(); link != links.end(); link++) {
+ const std::string &src = link->first;
+ const std::string &dest = link->second;
+
+ TarFileList::iterator dest_file = _tar_filelist.find(dest);
+ if (dest_file != _tar_filelist.end()) {
+ /* Link to file. Process the link like the destination file. */
+ _tar_filelist.insert(TarFileList::value_type(src, dest_file->second));
+ } else {
+ /* Destination file not found. Assume 'link to directory' */
+ /* Append PATHSEPCHAR to 'src' and 'dest' */
+ const std::string src_path = src + PATHSEPCHAR;
+ const std::string dst_path = (dest.length() == 0 ? "" : dest + PATHSEPCHAR);
+ _tar_linklist.insert(TarLinkList::value_type(src_path, dst_path));
+ }
+ }
+
return true;
}
generated by cgit v1.2.3-70-g09d2 (git 2.47.1) at 2024-12-20 20:40:25 +0000