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 <signal.h>
   7 #include <stdint.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <unistd.h>
  12
  13 #include <lzma.h>
  14 #include <libuntar.h>
  15
  16 #ifndef PATH_MAX
  17 #define PATH_MAX 4096
  18 #endif
  19
  20 #include "vis-single-payload.inc"
  21
  22 #ifndef VIS_TMP
  23 #define VIS_TMP "/tmp/.vis-single-XXXXXX"
  24 #endif
  25
  26 #ifndef VIS_TERMINFO
  27 #define VIS_TERMINFO "/etc/terminfo:/lib/terminfo:/usr/share/terminfo:" \
  28         "/usr/lib/terminfo:/usr/local/share/terminfo:/usr/local/lib/terminfo"
  29 #endif
  30
  31 static lzma_stream strm = LZMA_STREAM_INIT;
  32
  33 static int libtar_xzopen(const char *pathname, int flags, ...) {
  34         int ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_TELL_UNSUPPORTED_CHECK | LZMA_CONCATENATED);
  35         if (ret != LZMA_OK) {
  36                 fprintf(stderr, "lzma_stream_decoder error: %d\n", ret);
  37                 return ret;
  38         }
  39
  40         strm.next_in = vis_single_payload;
  41         strm.avail_in = sizeof(vis_single_payload);
  42
  43         return ret;
  44 }
  45
  46 static int libtar_xzclose(int fd) {
  47         lzma_end(&strm);
  48         return 0;
  49 }
  50
  51 static ssize_t libtar_xzread(int fd, void *buf, size_t count) {
  52         strm.next_out = buf;
  53         strm.avail_out = count;
  54
  55         int ret = lzma_code(&strm, LZMA_FINISH);
  56         if (ret != LZMA_OK && ret != LZMA_STREAM_END) {
  57                 fprintf(stderr, "lzma_code error: %d\n", ret);
  58                 return -1;
  59         }
  60
  61         return count - strm.avail_out;
  62 }
  63
  64 tartype_t xztype = {
  65         libtar_xzopen,
  66         libtar_xzclose,
  67         libtar_xzread,
  68 };
  69
  70 int extract(char *directory) {
  71         TAR *tar;
  72
  73         if (tar_open(&tar, NULL, &xztype, O_RDONLY, 0, 0) == -1) {
  74                 perror("tar_open");
  75                 return -1;
  76         }
  77
  78         if (tar_extract_all(tar, directory) != 0) {
  79                 perror("tar_extract_all");
  80                 return -1;
  81         }
  82
  83         if (tar_close(tar) != 0) {
  84                 perror("tar_close");
  85                 return -1;
  86         }
  87
  88         return 0;
  89 }
  90
  91 static int unlink_cb(const char *path, const struct stat *sb, int typeflag, struct FTW *ftwbuf) {
  92         return remove(path);
  93 }
  94
  95 int main(int argc, char **argv) {
  96         int rc = EXIT_FAILURE;
  97         char exe[256], path[PATH_MAX];
  98         char tmp_dirname[] = VIS_TMP;
  99
 100         if (!mkdtemp(tmp_dirname)) {
 101                 perror("mkdtemp");
 102                 return rc;
 103         }
 104
 105         char *old_path = getenv("PATH");
 106         if (snprintf(path, sizeof(path), "%s%s%s", tmp_dirname,
 107                      old_path ? ":" : "", old_path ? old_path : "") < 0) {
 108                 goto err;
 109         }
 110
 111         if (setenv("PATH", path, 1) == -1 ||
 112             setenv("TERMINFO_DIRS", VIS_TERMINFO, 0) == -1) {
 113                 perror("setenv");
 114                 goto err;
 115         }
 116
 117         if (extract(tmp_dirname) != 0)
 118                 goto err;
 119
 120         if (snprintf(exe, sizeof(exe), "%s/vis", tmp_dirname) < 0)
 121                 goto err;
 122
 123         int child_pid = fork();
 124         if (child_pid == -1) {
 125                 perror("fork");
 126                 goto err;
 127         } else if (child_pid == 0) {
 128                 execv(exe, argv);
 129                 perror("execv");
 130                 return EXIT_FAILURE;
 131         }
 132
 133         signal(SIGINT, SIG_IGN);
 134
 135         for (;;) {
 136                 int status;
 137                 int w = waitpid(child_pid, &status, 0);
 138                 if (w == -1) {
 139                         perror("waitpid");
 140                         break;
 141                 }
 142                 if (w == child_pid) {
 143                         rc = WEXITSTATUS(status);
 144                         break;
 145                 }
 146         }
 147
 148 err:
 149         nftw(tmp_dirname, unlink_cb, 64, FTW_DEPTH|FTW_PHYS|FTW_MOUNT);
 150         return rc;
 151 }