2d7b5bfa9
Denys Vlasenko
2009-07-05
Subject
cp: by popular demand, make it POSIX compliant (but less safe)
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
libbb/Config.in+10 -0
| @@ -114,6 +114,16 @@ config FEATURE_EDITING_ASK_TERMINAL | |
| correctly, or want to save on code size (about 300 bytes), | |
| then do not turn this option on. | |
| + | config FEATURE_NON_POSIX_CP |
| + | bool "Non-POSIX, but safer, copying to special nodes" |
| + | default y |
| + | help |
| + | With this option, "cp file symlink" will delete symlink |
| + | and create a regular file. This does not conform to POSIX, |
| + | but prevents a symlink attack. |
| + | Similarly, "cp file device" will not send file's data |
| + | to the device. |
| + | |
| config FEATURE_VERBOSE_CP_MESSAGE | |
| bool "Give more precise messages when copy fails (cp, mv etc)" | |
| default n | |
libbb/copy_file.c+9 -9
| @@ -8,9 +8,10 @@ | |
| * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. | |
| * | |
| */ | |
| - | |
| #include "libbb.h" | |
| + | // FEATURE_NON_POSIX_CP: |
| + | // |
| // POSIX: if exists and -i, ask (w/o -i assume yes). | |
| // Then open w/o EXCL (yes, not unlink!). | |
| // If open still fails and -f, try unlink, then try open again. | |
| @@ -23,22 +24,21 @@ | |
| // NB: we have special code which still allows for "cp file /dev/node" | |
| // to work POSIX-ly (the only realistic case where it makes sense) | |
| - | #define DO_POSIX_CP 0 /* 1 - POSIX behavior, 0 - safe behavior */ |
| - | |
| // errno must be set to relevant value ("why we cannot create dest?") | |
| // for POSIX mode to give reasonable error message | |
| static int ask_and_unlink(const char *dest, int flags) | |
| { | |
| int e = errno; | |
| - | #if DO_POSIX_CP |
| + | #if !ENABLE_FEATURE_NON_POSIX_CP |
| if (!(flags & (FILEUTILS_FORCE|FILEUTILS_INTERACTIVE))) { | |
| // Either it exists, or the *path* doesnt exist | |
| bb_perror_msg("cannot create '%s'", dest); | |
| return -1; | |
| } | |
| #endif | |
| - | // If !DO_POSIX_CP, act as if -f is always in effect - we don't want |
| - | // "cannot create" msg, we want unlink to be done (silently unless -i). |
| + | // If ENABLE_FEATURE_NON_POSIX_CP, act as if -f is always in effect |
| + | // - we don't want "cannot create" msg, we want unlink to be done |
| + | // (silently unless -i). |
| // TODO: maybe we should do it only if ctty is present? | |
| if (flags & FILEUTILS_INTERACTIVE) { | |
| @@ -279,10 +279,10 @@ int FAST_FUNC copy_file(const char *source, const char *dest, int flags) | |
| * non-interactive cp. NB: it is still racy | |
| * for "cp file /home/bad_user/file" case | |
| * (user can rm file and create a link to /etc/passwd) */ | |
| - | if (DO_POSIX_CP |
| + | if (!ENABLE_FEATURE_NON_POSIX_CP |
| || (dest_exists | |
| - | && !(flags & (FILEUTILS_RECUR|FILEUTILS_INTERACTIVE)) |
| - | && !S_ISLNK(dest_stat.st_mode)) |
| + | && !(flags & (FILEUTILS_RECUR|FILEUTILS_INTERACTIVE)) |
| + | && !S_ISLNK(dest_stat.st_mode)) |
| ) { | |
| dst_fd = open(dest, O_WRONLY|O_CREAT|O_TRUNC, new_mode); | |
| } else /* safe way: */ | |