archival/libarchive/data_extract_to_command.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   4  */
   5 #include "libbb.h"
   6 #include "bb_archive.h"
   7
   8 enum {
   9         //TAR_FILETYPE,
  10         TAR_MODE,
  11         TAR_FILENAME,
  12         TAR_REALNAME,
  13 #if ENABLE_FEATURE_TAR_UNAME_GNAME
  14         TAR_UNAME,
  15         TAR_GNAME,
  16 #endif
  17         TAR_SIZE,
  18         TAR_UID,
  19         TAR_GID,
  20         TAR_MAX,
  21 };
  22
  23 static const char *const tar_var[] = {
  24         // "FILETYPE",
  25         "MODE",
  26         "FILENAME",
  27         "REALNAME",
  28 #if ENABLE_FEATURE_TAR_UNAME_GNAME
  29         "UNAME",
  30         "GNAME",
  31 #endif
  32         "SIZE",
  33         "UID",
  34         "GID",
  35 };
  36
  37 static void xputenv(char *str)
  38 {
  39         if (putenv(str))
  40                 bb_die_memory_exhausted();
  41 }
  42
  43 static void str2env(char *env[], int idx, const char *str)
  44 {
  45         env[idx] = xasprintf("TAR_%s=%s", tar_var[idx], str);
  46         xputenv(env[idx]);
  47 }
  48
  49 static void dec2env(char *env[], int idx, unsigned long long val)
  50 {
  51         env[idx] = xasprintf("TAR_%s=%llu", tar_var[idx], val);
  52         xputenv(env[idx]);
  53 }
  54
  55 static void oct2env(char *env[], int idx, unsigned long val)
  56 {
  57         env[idx] = xasprintf("TAR_%s=%lo", tar_var[idx], val);
  58         xputenv(env[idx]);
  59 }
  60
  61 void FAST_FUNC data_extract_to_command(archive_handle_t *archive_handle)
  62 {
  63         file_header_t *file_header = archive_handle->file_header;
  64
  65 #if 0 /* do we need this? ENABLE_FEATURE_TAR_SELINUX */
  66         char *sctx = archive_handle->tar__sctx[PAX_NEXT_FILE];
  67         if (!sctx)
  68                 sctx = archive_handle->tar__sctx[PAX_GLOBAL];
  69         if (sctx) { /* setfscreatecon is 4 syscalls, avoid if possible */
  70                 setfscreatecon(sctx);
  71                 free(archive_handle->tar__sctx[PAX_NEXT_FILE]);
  72                 archive_handle->tar__sctx[PAX_NEXT_FILE] = NULL;
  73         }
  74 #endif
  75
  76         if ((file_header->mode & S_IFMT) == S_IFREG) {
  77                 pid_t pid;
  78                 int p[2], status;
  79                 char *tar_env[TAR_MAX];
  80
  81                 memset(tar_env, 0, sizeof(tar_env));
  82
  83                 xpipe(p);
  84                 pid = BB_MMU ? xfork() : xvfork();
  85                 if (pid == 0) {
  86                         /* Child */
  87                         /* str2env(tar_env, TAR_FILETYPE, "f"); - parent should do it once */
  88                         oct2env(tar_env, TAR_MODE, file_header->mode);
  89                         str2env(tar_env, TAR_FILENAME, file_header->name);
  90                         str2env(tar_env, TAR_REALNAME, file_header->name);
  91 #if ENABLE_FEATURE_TAR_UNAME_GNAME
  92                         str2env(tar_env, TAR_UNAME, file_header->tar__uname);
  93                         str2env(tar_env, TAR_GNAME, file_header->tar__gname);
  94 #endif
  95                         dec2env(tar_env, TAR_SIZE, file_header->size);
  96                         dec2env(tar_env, TAR_UID, file_header->uid);
  97                         dec2env(tar_env, TAR_GID, file_header->gid);
  98                         close(p[1]);
  99                         xdup2(p[0], STDIN_FILENO);
 100                         signal(SIGPIPE, SIG_DFL);
 101                         execl(archive_handle->tar__to_command_shell,
 102                                 archive_handle->tar__to_command_shell,
 103                                 "-c",
 104                                 archive_handle->tar__to_command,
 105                                 (char *)0);
 106                         bb_perror_msg_and_die("can't execute '%s'", archive_handle->tar__to_command_shell);
 107                 }
 108                 close(p[0]);
 109                 /* Our caller is expected to do signal(SIGPIPE, SIG_IGN)
 110                  * so that we don't die if child don't read all the input: */
 111                 bb_copyfd_exact_size(archive_handle->src_fd, p[1], -file_header->size);
 112                 close(p[1]);
 113
 114                 status = wait_for_exitstatus(pid);
 115                 if (WIFEXITED(status) && WEXITSTATUS(status))
 116                         bb_error_msg_and_die("'%s' returned status %d",
 117                                 archive_handle->tar__to_command, WEXITSTATUS(status));
 118                 if (WIFSIGNALED(status))
 119                         bb_error_msg_and_die("'%s' terminated by signal %d",
 120                                 archive_handle->tar__to_command, WTERMSIG(status));
 121
 122                 if (!BB_MMU) {
 123                         int i;
 124                         for (i = 0; i < TAR_MAX; i++) {
 125                                 if (tar_env[i])
 126                                         bb_unsetenv_and_free(tar_env[i]);
 127                         }
 128                 }
 129         }
 130
 131 #if 0 /* ENABLE_FEATURE_TAR_SELINUX */
 132         if (sctx)
 133                 /* reset the context after creating an entry */
 134                 setfscreatecon(NULL);
 135 #endif
 136 }