vis-single.c

   1 #include <sys/wait.h>
   2 #include <errno.h>
   3 #include <fcntl.h>
   4 #include <ftw.h>
   5 #include <limits.h>
   6 #include <stdint.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <unistd.h>
  11
  12 #include <lzma.h>
  13 #include <libuntar.h>
  14
  15 #ifndef PATH_MAX
  16 #define PATH_MAX 4096
  17 #endif
  18
  19 #include "vis-single-payload.inc"
  20
  21 #ifndef VIS_TMP
  22 #define VIS_TMP "/tmp/.vis-single-XXXXXX"
  23 #endif
  24
  25 #ifndef VIS_TERMINFO
  26 #define VIS_TERMINFO "/etc/terminfo:/lib/terminfo:/usr/share/terminfo:" \
  27         "/usr/lib/terminfo:/usr/local/share/terminfo:/usr/local/lib/terminfo"
  28 #endif
  29
  30 static lzma_stream strm = LZMA_STREAM_INIT;
  31
  32 static int libtar_xzopen(const char *pathname, int flags, ...) {
  33         int ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_TELL_UNSUPPORTED_CHECK | LZMA_CONCATENATED);
  34         if (ret != LZMA_OK) {
  35                 fprintf(stderr, "lzma_stream_decoder error: %d\n", ret);
  36                 return ret;
  37         }
  38
  39         strm.next_in = vis_single_payload;
  40         strm.avail_in = sizeof(vis_single_payload);
  41
  42         return ret;
  43 }
  44
  45 static int libtar_xzclose(int fd) {
  46         lzma_end(&strm);
  47         return 0;
  48 }
  49
  50 static ssize_t libtar_xzread(int fd, void *buf, size_t count) {
  51         strm.next_out = buf;
  52         strm.avail_out = count;
  53
  54         int ret = lzma_code(&strm, LZMA_FINISH);
  55         if (ret != LZMA_OK && ret != LZMA_STREAM_END) {
  56                 fprintf(stderr, "lzma_code error: %d\n", ret);
  57                 return -1;
  58         }
  59
  60         return count - strm.avail_out;
  61 }
  62
  63 tartype_t xztype = {
  64         libtar_xzopen,
  65         libtar_xzclose,
  66         libtar_xzread,
  67 };
  68
  69 int extract(char *directory) {
  70         TAR *tar;
  71
  72         if (tar_open(&tar, NULL, &xztype, O_RDONLY, 0, 0) == -1) {
  73                 perror("tar_open");
  74                 return -1;
  75         }
  76
  77         if (tar_extract_all(tar, directory) != 0) {
  78                 perror("tar_extract_all");
  79                 return -1;
  80         }
  81
  82         if (tar_close(tar) != 0) {
  83                 perror("tar_close");
  84                 return -1;
  85         }
  86
  87         return 0;
  88 }
  89
  90 static int unlink_cb(const char *path, const struct stat *sb, int typeflag, struct FTW *ftwbuf) {
  91         return remove(path);
  92 }
  93
  94 int main(int argc, char **argv) {
  95         int rc = EXIT_FAILURE;
  96         char exe[256], path[PATH_MAX];
  97         char tmp_dirname[] = VIS_TMP;
  98
  99         if (!mkdtemp(tmp_dirname)) {
 100                 perror("mkdtemp");
 101                 return rc;
 102         }
 103
 104         char *old_path = getenv("PATH");
 105         if (snprintf(path, sizeof(path), "%s%s%s", tmp_dirname,
 106                      old_path ? ":" : "", old_path ? old_path : "") < 0) {
 107                 goto err;
 108         }
 109
 110         if (setenv("PATH", path, 1) == -1 ||
 111             setenv("TERMINFO_DIRS", VIS_TERMINFO, 0) == -1) {
 112                 perror("setenv");
 113                 goto err;
 114         }
 115
 116         if (extract(tmp_dirname) != 0)
 117                 goto err;
 118
 119         if (snprintf(exe, sizeof(exe), "%s/vis", tmp_dirname) < 0)
 120                 goto err;
 121
 122         int child_pid = fork();
 123         if (child_pid == -1) {
 124                 perror("fork");
 125                 goto err;
 126         } else if (child_pid == 0) {
 127                 execv(exe, argv);
 128                 perror("execv");
 129                 return EXIT_FAILURE;
 130         }
 131
 132         signal(SIGINT, SIG_IGN);
 133
 134         for (;;) {
 135                 int status;
 136                 int w = waitpid(child_pid, &status, 0);
 137                 if (w == -1) {
 138                         perror("waitpid");
 139                         break;
 140                 }
 141                 if (w == child_pid) {
 142                         rc = WEXITSTATUS(status);
 143                         break;
 144                 }
 145         }
 146
 147 err:
 148         nftw(tmp_dirname, unlink_cb, 64, FTW_DEPTH|FTW_PHYS|FTW_MOUNT);
 149         return rc;
 150 }