From 13ae85edd1e097299297062a1054ccbe8fb97fe3 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 20 Jul 2017 18:34:51 +0200 Subject: [PATCH] unzip: support symlinks. Closes 10031 function old new delta unzip_main 2519 2667 +148 Signed-off-by: Denys Vlasenko --- archival/unzip.c | 61 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 48 insertions(+), 13 deletions(-) diff --git a/archival/unzip.c b/archival/unzip.c index d6b8da347..44c4a3125 100644 --- a/archival/unzip.c +++ b/archival/unzip.c @@ -334,6 +334,38 @@ static void unzip_create_leading_dirs(const char *fn) free(name); } +static void unzip_extract_symlink(zip_header_t *zip, const char *dst_fn) +{ + char *target; + + if (zip->fmt.ucmpsize > 0xfff) /* no funny business please */ + bb_error_msg_and_die("bad archive"); + + if (zip->fmt.method == 0) { + /* Method 0 - stored (not compressed) */ + target = xzalloc(zip->fmt.ucmpsize + 1); + xread(zip_fd, target, zip->fmt.ucmpsize); + } else { +#if 1 + bb_error_msg_and_die("compressed symlink is not supported"); +#else + transformer_state_t xstate; + init_transformer_state(&xstate); + xstate.mem_output_size_max = zip->fmt.ucmpsize; + /* ...unpack... */ + if (!xstate.mem_output_buf) + WTF(); + target = xstate.mem_output_buf; + target = xrealloc(target, xstate.mem_output_size + 1); + target[xstate.mem_output_size] = '\0'; +#endif + } +//TODO: libbb candidate + if (symlink(target, dst_fn)) + bb_perror_msg_and_die("can't create symlink '%s'", dst_fn); + free(target); +} + static void unzip_extract(zip_header_t *zip, int dst_fd) { transformer_state_t xstate; @@ -346,12 +378,6 @@ static void unzip_extract(zip_header_t *zip, int dst_fd) return; } -// NB: to support symlinks, need to extract symlink target. A-la: -// xstate.mem_output_size_max = zip->fmt.ucmpsize; -// ...unpack... -// if (xstate.mem_output_buf) { success, xstate.mem_output_size is the size } -// Although archives I've seen have fmt.method == 0 for symlinks. - init_transformer_state(&xstate); xstate.bytes_in = zip->fmt.cmpsize; xstate.src_fd = zip_fd; @@ -719,7 +745,6 @@ int unzip_main(int argc, char **argv) if ((cdf.fmt.version_made_by >> 8) == 3) { /* This archive is created on Unix */ dir_mode = file_mode = (cdf.fmt.external_attributes >> 16); -//TODO: if (S_ISLNK(file_mode)) this is a symlink } } #endif @@ -833,7 +858,7 @@ int unzip_main(int argc, char **argv) } check_file: /* Extract file */ - if (stat(dst_fn, &stat_buf) == -1) { + if (lstat(dst_fn, &stat_buf) == -1) { /* File does not exist */ if (errno != ENOENT) { bb_perror_msg_and_die("can't stat '%s'", dst_fn); @@ -854,6 +879,7 @@ int unzip_main(int argc, char **argv) goto do_open_and_extract; printf("replace %s? [y]es, [n]o, [A]ll, [N]one, [r]ename: ", dst_fn); my_fgets80(key_buf); +//TODO: redo lstat + ISREG check! user input could have taken a long time! switch (key_buf[0]) { case 'A': @@ -862,7 +888,8 @@ int unzip_main(int argc, char **argv) do_open_and_extract: unzip_create_leading_dirs(dst_fn); #if ENABLE_FEATURE_UNZIP_CDF - dst_fd = xopen3(dst_fn, O_WRONLY | O_CREAT | O_TRUNC, file_mode); + if (!S_ISLNK(file_mode)) + dst_fd = xopen3(dst_fn, O_WRONLY | O_CREAT | O_TRUNC, file_mode); #else dst_fd = xopen(dst_fn, O_WRONLY | O_CREAT | O_TRUNC); #endif @@ -872,10 +899,18 @@ int unzip_main(int argc, char **argv) ? " extracting: %s\n" : */ " inflating: %s\n", dst_fn); } - unzip_extract(&zip, dst_fd); - if (dst_fd != STDOUT_FILENO) { - /* closing STDOUT is potentially bad for future business */ - close(dst_fd); +#if ENABLE_FEATURE_UNZIP_CDF + if (S_ISLNK(file_mode)) { + if (dst_fd != STDOUT_FILENO) /* no -p */ + unzip_extract_symlink(&zip, dst_fn); + } else +#endif + { + unzip_extract(&zip, dst_fd); + if (dst_fd != STDOUT_FILENO) { + /* closing STDOUT is potentially bad for future business */ + close(dst_fd); + } } break; -- 2.25.1