Merge branch 'busybox' into merge

1 files changed, 141 insertions, 64 deletions

diff --git a/archival/unzip.c b/archival/unzip.c
index 8dfc4e678..4c4feda82 100644
--- a/archival/unzip.c
+++ b/archival/unzip.c
@@ -17,23 +17,23 @@
  * Zip64 + other methods
  */
 //config:config UNZIP
-//config:       bool "unzip"
+//config:       bool "unzip (24 kb)"
 //config:       default y
 //config:       help
-//config:         unzip will list or extract files from a ZIP archive,
-//config:         commonly found on DOS/WIN systems. The default behavior
-//config:         (with no options) is to extract the archive into the
-//config:         current directory.
+//config:       unzip will list or extract files from a ZIP archive,
+//config:       commonly found on DOS/WIN systems. The default behavior
+//config:       (with no options) is to extract the archive into the
+//config:       current directory.
 //config:
 //config:config FEATURE_UNZIP_CDF
 //config:       bool "Read and use Central Directory data"
 //config:       default y
 //config:       depends on UNZIP
 //config:       help
-//config:         If you know that you only need to deal with simple
-//config:         ZIP files without deleted/updated files, SFX archives etc,
-//config:         you can reduce code size by unselecting this option.
-//config:         To support less trivial ZIPs, say Y.
+//config:       If you know that you only need to deal with simple
+//config:       ZIP files without deleted/updated files, SFX archives etc,
+//config:       you can reduce code size by unselecting this option.
+//config:       To support less trivial ZIPs, say Y.
 //config:
 //config:config FEATURE_UNZIP_BZIP2
 //config:       bool "Support compression method 12 (bzip2)"
@@ -62,6 +62,7 @@
 //usage:     "\n        -l      List contents (with -q for short form)"
 //usage:     "\n        -n      Never overwrite files (default: ask)"
 //usage:     "\n        -o      Overwrite"
+//usage:     "\n        -j      Do not restore paths"
 //usage:     "\n        -p      Print to stdout"
 //usage:     "\n        -q      Quiet"
 //usage:     "\n        -x FILE Exclude FILEs"
@@ -320,6 +321,12 @@ static uint32_t read_next_cdf(uint32_t cdf_offset, cdf_header_t *cdf)
 };
 #endif
 
+static void die_if_bad_fnamesize(unsigned sz)
+{
+        if (sz > 0xfff) /* more than 4k?! no funny business please */
+                bb_error_msg_and_die("bad archive");
+}
+
 static void unzip_skip(off_t skip)
 {
         if (skip != 0)
@@ -337,6 +344,39 @@ static void unzip_create_leading_dirs(const char *fn)
         free(name);
 }
 
+#if ENABLE_FEATURE_UNZIP_CDF
+static void unzip_extract_symlink(zip_header_t *zip, const char *dst_fn)
+{
+        char *target;
+
+        die_if_bad_fnamesize(zip->fmt.ucmpsize);
+
+        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);
+}
+#endif
+
 static void unzip_extract(zip_header_t *zip, int dst_fd)
 {
         transformer_state_t xstate;
@@ -349,12 +389,6 @@ 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;
@@ -414,16 +448,32 @@ static void my_fgets80(char *buf80)
         }
 }
 
+static int get_lstat_mode(const char *dst_fn)
+{
+        struct stat stat_buf;
+        if (lstat(dst_fn, &stat_buf) == -1) {
+                if (errno != ENOENT) {
+                        bb_perror_msg_and_die("can't stat '%s'", dst_fn);
+                }
+                /* File does not exist */
+                return -1;
+        }
+        return stat_buf.st_mode;
+}
+
 int unzip_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int unzip_main(int argc, char **argv)
 {
-        enum { O_PROMPT, O_NEVER, O_ALWAYS };
-
+        enum {
+                OPT_l = (1 << 0),
+                OPT_x = (1 << 1),
+                OPT_j = (1 << 2),
+        };
+        unsigned opts;
         smallint quiet = 0;
         IF_NOT_FEATURE_UNZIP_CDF(const) smallint verbose = 0;
-        smallint listing = 0;
+        enum { O_PROMPT, O_NEVER, O_ALWAYS };
         smallint overwrite = O_PROMPT;
-        smallint x_opt_seen;
         uint32_t cdf_offset;
         unsigned long total_usize;
         unsigned long total_size;
@@ -434,9 +484,8 @@ int unzip_main(int argc, char **argv)
         llist_t *zaccept = NULL;
         llist_t *zreject = NULL;
         char *base_dir = NULL;
-        int i, opt;
+        int i;
         char key_buf[80]; /* must match size used by my_fgets80 */
-        struct stat stat_buf;
 
 /* -q, -l and -v: UnZip 5.52 of 28 February 2005, by Info-ZIP:
  *
@@ -479,16 +528,16 @@ int unzip_main(int argc, char **argv)
  *    204372                   1 file
  */
 
-        x_opt_seen = 0;
+        opts = 0;
         /* '-' makes getopt return 1 for non-options */
-        while ((opt = getopt(argc, argv, "-d:lnopqxv")) != -1) {
-                switch (opt) {
+        while ((i = getopt(argc, argv, "-d:lnopqxjv")) != -1) {
+                switch (i) {
                 case 'd':  /* Extract to base directory */
                         base_dir = optarg;
                         break;
 
                 case 'l': /* List */
-                        listing = 1;
+                        opts |= OPT_l;
                         break;
 
                 case 'n': /* Never overwrite existing files */
@@ -508,11 +557,15 @@ int unzip_main(int argc, char **argv)
 
                 case 'v': /* Verbose list */
                         IF_FEATURE_UNZIP_CDF(verbose++;)
-                        listing = 1;
+                        opts |= OPT_l;
                         break;
 
                 case 'x':
-                        x_opt_seen = 1;
+                        opts |= OPT_x;
+                        break;
+
+                case 'j':
+                        opts |= OPT_j;
                         break;
 
                 case 1:
@@ -521,7 +574,7 @@ int unzip_main(int argc, char **argv)
                                 /* +5: space for ".zip" and NUL */
                                 src_fn = xmalloc(strlen(optarg) + 5);
                                 strcpy(src_fn, optarg);
-                        } else if (!x_opt_seen) {
+                        } else if (!(opts & OPT_x)) {
                                 /* Include files */
                                 llist_add_to(&zaccept, optarg);
                         } else {
@@ -589,7 +642,7 @@ int unzip_main(int argc, char **argv)
         if (quiet <= 1) { /* not -qq */
                 if (quiet == 0)
                         printf("Archive:  %s\n", src_fn);
-                if (listing) {
+                if (opts & OPT_l) {
                         puts(verbose ?
                                 " Length   Method    Size  Cmpr    Date    Time   CRC-32   Name\n"
                                 "--------  ------  ------- ---- ---------- ----- --------  ----"
@@ -722,7 +775,6 @@ 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
@@ -740,15 +792,22 @@ int unzip_main(int argc, char **argv)
 
                 /* Read filename */
                 free(dst_fn);
+                die_if_bad_fnamesize(zip.fmt.filename_len);
                 dst_fn = xzalloc(zip.fmt.filename_len + 1);
                 xread(zip_fd, dst_fn, zip.fmt.filename_len);
-
                 /* Skip extra header bytes */
                 unzip_skip(zip.fmt.extra_len);
 
                 /* Guard against "/abspath", "/../" and similar attacks */
                 overlapping_strcpy(dst_fn, strip_unsafe_prefix(dst_fn));
 
+                if (opts & OPT_j) /* Strip paths? */
+                        overlapping_strcpy(dst_fn, bb_basename(dst_fn));
+
+                /* Did this strip everything ("DIR/" case)? Then skip */
+                if (!dst_fn[0])
+                        goto skip_cmpsize;
+
                 /* Filter zip entries */
                 if (find_list_entry(zreject, dst_fn)
                  || (zaccept && !find_list_entry(zaccept, dst_fn))
@@ -756,7 +815,7 @@ int unzip_main(int argc, char **argv)
                         goto skip_cmpsize;
                 }
 
-                if (listing) {
+                if (opts & OPT_l) {
                         /* List entry */
                         char dtbuf[sizeof("mm-dd-yyyy hh:mm")];
                         sprintf(dtbuf, "%02u-%02u-%04u %02u:%02u",
@@ -814,11 +873,11 @@ int unzip_main(int argc, char **argv)
                         goto do_extract;
                 }
                 if (last_char_is(dst_fn, '/')) {
+                        int mode;
+
                         /* Extract directory */
-                        if (stat(dst_fn, &stat_buf) == -1) {
-                                if (errno != ENOENT) {
-                                        bb_perror_msg_and_die("can't stat '%s'", dst_fn);
-                                }
+                        mode = get_lstat_mode(dst_fn);
+                        if (mode == -1) { /* ENOENT */
                                 if (!quiet) {
                                         printf("   creating: %s\n", dst_fn);
                                 }
@@ -827,7 +886,7 @@ int unzip_main(int argc, char **argv)
                                         xfunc_die();
                                 }
                         } else {
-                                if (!S_ISDIR(stat_buf.st_mode)) {
+                                if (!S_ISDIR(mode)) {
                                         bb_error_msg_and_die("'%s' exists but is not a %s",
                                                 dst_fn, "directory");
                                 }
@@ -835,29 +894,33 @@ int unzip_main(int argc, char **argv)
                         goto skip_cmpsize;
                 }
  check_file:
-                /* Extract file */
-                if (stat(dst_fn, &stat_buf) == -1) {
-                        /* File does not exist */
-                        if (errno != ENOENT) {
-                                bb_perror_msg_and_die("can't stat '%s'", dst_fn);
+                /* Does target file already exist? */
+                {
+                        int mode = get_lstat_mode(dst_fn);
+                        if (mode == -1) {
+                                /* ENOENT: does not exist */
+                                goto do_open_and_extract;
                         }
-                        goto do_open_and_extract;
-                }
-                /* File already exists */
-                if (overwrite == O_NEVER) {
-                        goto skip_cmpsize;
-                }
-                if (!S_ISREG(stat_buf.st_mode)) {
-                        /* File is not regular file */
-                        bb_error_msg_and_die("'%s' exists but is not a %s",
-                                dst_fn, "regular file");
+                        if (overwrite == O_NEVER) {
+                                goto skip_cmpsize;
+                        }
+                        if (!S_ISREG(mode)) {
+ fishy:
+                                bb_error_msg_and_die("'%s' exists but is not a %s",
+                                        dst_fn, "regular file");
+                        }
+                        if (overwrite == O_ALWAYS) {
+                                goto do_open_and_extract;
+                        }
+                        printf("replace %s? [y]es, [n]o, [A]ll, [N]one, [r]ename: ", dst_fn);
+                        my_fgets80(key_buf);
+                        /* User input could take a long time. Is it still a regular file? */
+                        mode = get_lstat_mode(dst_fn);
+                        if (!S_ISREG(mode))
+                                goto fishy;
                 }
-                /* File is regular file */
-                if (overwrite == O_ALWAYS)
-                        goto do_open_and_extract;
-                printf("replace %s? [y]es, [n]o, [A]ll, [N]one, [r]ename: ", dst_fn);
-                my_fgets80(key_buf);
 
+                /* Extract (or skip) it */
                 switch (key_buf[0]) {
                 case 'A':
                         overwrite = O_ALWAYS;
@@ -865,9 +928,15 @@ 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);
+                        dst_fd = -1;
+                        if (!S_ISLNK(file_mode)) {
+                                dst_fd = xopen3(dst_fn,
+                                        O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW,
+                                        file_mode);
+                        }
 #else
-                        dst_fd = xopen(dst_fn, O_WRONLY | O_CREAT | O_TRUNC);
+                        /* O_NOFOLLOW defends against symlink attacks */
+                        dst_fd = xopen(dst_fn, O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW);
 #endif
  do_extract:
                         if (!quiet) {
@@ -875,10 +944,18 @@ 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) /* not -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;
 
@@ -906,7 +983,7 @@ int unzip_main(int argc, char **argv)
                 total_entries++;
         }
 
-        if (listing && quiet <= 1) {
+        if ((opts & OPT_l) && quiet <= 1) {
                 if (!verbose) {
                         //      "  Length      Date    Time    Name\n"
                         //      "---------  ---------- -----   ----"