static int mov_open_dref(AVIOContext **pb, const char *src, MOVDref *ref, AVIOInterruptCB *int_cb, int use_absolute_path, AVFormatContext *fc) { /* try relative path, we do not try the absolute because it can leak information about our system to an attacker */ if (ref->nlvl_to > 0 && ref->nlvl_from > 0) { char filename[1024]; const char *src_path; int i, l; /* find a source dir */ src_path = strrchr(src, '/'); if (src_path) src_path++; else src_path = src; /* find a next level down to target */ for (i = 0, l = strlen(ref->path) - 1; l >= 0; l--) if (ref->path[l] == '/') { if (i == ref->nlvl_to - 1) break; else i++; } /* compose filename if next level down to target was found */ if (i == ref->nlvl_to - 1 && src_path - src < sizeof(filename)) { memcpy(filename, src, src_path - src); filename[src_path - src] = 0; for (i = 1; i < ref->nlvl_from; i++) av_strlcat(filename, "../", sizeof(filename)); av_strlcat(filename, ref->path + l + 1, sizeof(filename)); if (!avio_open2(pb, filename, AVIO_FLAG_READ, int_cb, NULL)) return 0; } } else if (use_absolute_path) { av_log(fc, AV_LOG_WARNING, "Using absolute path on user request, " "this is a possible security issue\n"); if (!avio_open2(pb, ref->path, AVIO_FLAG_READ, int_cb, NULL)) return 0; } return AVERROR(ENOENT); }