Refactor spec extraction on tar build to address several issues

- simplify the code
- use %{__tar} instead of tar as the extraction command
- avoid sprintf to "big enough" buffer
- basic spec sanity check while extracting, fixes rhbz#281391

diff --git a/build.c b/build.c
index 7376454..072270d 100644 (file)
--- a/build.c
+++ b/build.c
@@ -120,13 +120,19 @@ static int buildForTarget(rpmts ts, const char * arg, BTA_t ba)
        char * specDir;
        char * tmpSpecFile;
        char * cmd, * s;
+       const char **try;
+       int gotspec = 0;
+       char *tar;
        rpmCompressedMagic res = COMPRESSED_OTHER;
        static const char *zcmds[] =
                { "cat", "gunzip", "bunzip2", "cat" };
+       static const char *tryspec[] = { "Specfile", "\\*.spec", NULL };
 
        specDir = rpmGetPath("%{_specdir}", NULL);
 
-       tmpSpecFile = (char *) rpmGetPath("%{_specdir}/", "rpm-spec.XXXXXX", NULL);
+       tmpSpecFile = rpmGetPath("%{_specdir}/", "rpm-spec.XXXXXX", NULL);
+       tar = rpmGetPath("%{__tar}", NULL);
+
 #if defined(HAVE_MKSTEMP)
        (void) close(mkstemp(tmpSpecFile));
 #else
@@ -135,38 +141,31 @@ static int buildForTarget(rpmts ts, const char * arg, BTA_t ba)
 
        (void) rpmFileIsCompressed(arg, &res);
 
-       cmd = alloca(strlen(arg) + 50 + strlen(tmpSpecFile));
-       sprintf(cmd, "%s < '%s' | tar xOvf - Specfile 2>&1 > '%s'",
-                       zcmds[res & 0x3], arg, tmpSpecFile);
-       if (!(fp = popen(cmd, "r"))) {
-           rpmlog(RPMLOG_ERR, _("Failed to open tar pipe: %m\n"));
-           specDir = _free(specDir);
-           tmpSpecFile = _free(tmpSpecFile);
-           return 1;
-       }
-       if ((!fgets(buf, sizeof(buf) - 1, fp)) || !strchr(buf, '/')) {
-           /* Try again */
-           (void) pclose(fp);
+       for (try = tryspec; *try != NULL; try++) {
+           rasprintf(&cmd, "%s < '%s' | %s xOvf - %s 2>&1 > '%s'",
+                zcmds[res & 0x3], arg, tar, *try, tmpSpecFile);
 
-           sprintf(cmd, "%s < '%s' | tar xOvf - --wildcards \\*.spec 2>&1 > '%s'",
-                   zcmds[res & 0x3], arg, tmpSpecFile);
            if (!(fp = popen(cmd, "r"))) {
                rpmlog(RPMLOG_ERR, _("Failed to open tar pipe: %m\n"));
-               specDir = _free(specDir);
-               tmpSpecFile = _free(tmpSpecFile);
-               return 1;
-           }
-           if (!fgets(buf, sizeof(buf) - 1, fp)) {
-               /* Give up */
-               rpmlog(RPMLOG_ERR, _("Failed to read spec file from %s\n"),
-                       arg);
-               (void) unlink(tmpSpecFile);
-               specDir = _free(specDir);
-               tmpSpecFile = _free(tmpSpecFile);
-               return 1;
+           } else {
+               gotspec = fgets(buf, sizeof(buf) - 1, fp) && 
+                         isSpecFile(tmpSpecFile);
+               pclose(fp);
            }
+
+           if (!gotspec) 
+               unlink(tmpSpecFile);
+           free(cmd);
        }
-       (void) pclose(fp);
+
+       free(tar);
+       if (!gotspec) {
+           rpmlog(RPMLOG_ERR, _("Failed to read spec file from %s\n"), arg);
+           free(specDir);
+           free(tmpSpecFile);
+           return 1;
+       }
+
 
        cmd = s = buf;
        while (*cmd != '\0') {