diff options
Diffstat (limited to 'lib/tar/src/number.c')
-rw-r--r-- | lib/tar/src/number.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/lib/tar/src/number.c b/lib/tar/src/number.c new file mode 100644 index 0000000..2f179df --- /dev/null +++ b/lib/tar/src/number.c @@ -0,0 +1,79 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +/* + * number.c + * + * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at> + */ +#include "config.h" + +#include "tar/format.h" + +#include <ctype.h> +#include <stdio.h> + +int read_octal(const char *str, int digits, sqfs_u64 *out) +{ + sqfs_u64 result = 0; + + while (digits > 0 && isspace(*str)) { + ++str; + --digits; + } + + while (digits > 0 && *str >= '0' && *str <= '7') { + if (result > 0x1FFFFFFFFFFFFFFFUL) { + fputs("numeric overflow parsing tar header\n", stderr); + return -1; + } + + result = (result << 3) | (*(str++) - '0'); + --digits; + } + + *out = result; + return 0; +} + +static int read_binary(const char *str, int digits, sqfs_u64 *out) +{ + sqfs_u64 x, ov, result = 0; + bool first = true; + + while (digits > 0) { + x = *((const unsigned char *)str++); + --digits; + + if (first) { + first = false; + if (x == 0xFF) { + result = 0xFFFFFFFFFFFFFFFFUL; + } else { + x &= 0x7F; + result = 0; + if (digits > 7 && x != 0) + goto fail_ov; + } + } + + ov = (result >> 56) & 0xFF; + + if (ov != 0 && ov != 0xFF) + goto fail_ov; + + result = (result << 8) | x; + } + + *out = result; + return 0; +fail_ov: + fputs("numeric overflow parsing tar header\n", stderr); + return -1; +} + +int read_number(const char *str, int digits, sqfs_u64 *out) +{ + if (*((const unsigned char *)str) & 0x80) + return read_binary(str, digits, out); + + return read_octal(str, digits, out); +} |