Subject: [PATCH 2/8] generator: Optional arguments, add-drive-opts (RHBZ#642934,CVE-2010-3851).

int -guestfs__add_drive_ro_with_if (guestfs_h *g, const char *filename, - const char *drive_if) +guestfs__add_drive_opts (guestfs_h *g, const char *filename, + const struct guestfs_add_drive_opts_argv *optargs) { if (strchr (filename, ',') != NULL) { error (g, _("filename cannot contain ',' (comma) character")); return -1; } - if (access (filename, F_OK) == -1) { - perrorf (g, "%s", filename); + int readonly = + optargs->bitmask & GUESTFS_ADD_DRIVE_OPTS_READONLY_BITMASK + ? optargs->readonly : 0; + + const char *iface = + optargs->bitmask & GUESTFS_ADD_DRIVE_OPTS_IFACE_BITMASK + ? optargs->iface : DRIVE_IF; + + const char *format = + optargs->bitmask & GUESTFS_ADD_DRIVE_OPTS_FORMAT_BITMASK + ? optargs->format : NULL; + + /* For writable files, see if we can use cache=off. This also + * checks for the existence of the file. For readonly we have + * to do the check explicitly. + */ + int use_cache_off = readonly ? 0 : test_cache_off (g, filename); + if (use_cache_off == -1) return -1; + + if (readonly) { + if (access (filename, F_OK) == -1) { + perrorf (g, "%s", filename); + return -1; + } } - size_t len = strlen (filename) + 64; + /* Construct the final -drive parameter. */ + size_t len = 64 + strlen (filename) + strlen (iface); + if (format) len += strlen (format); char buf[len]; - snprintf (buf, len, "file=%s,snapshot=on,if=%s", filename, drive_if); + snprintf (buf, len, "file=%s%s%s%s%s,if=%s", + filename, + readonly ? ",snapshot=on" : "", + use_cache_off ? ",cache=off" : "", + format ? ",format=" : "", + format ? format : "", + iface);

return guestfs__config (g, "-drive", buf); }