diff options
Diffstat (limited to 'lib/nlattr.c')
| -rw-r--r-- | lib/nlattr.c | 39 |
1 files changed, 25 insertions, 14 deletions
diff --git a/lib/nlattr.c b/lib/nlattr.c index 07156e581997..447182543c03 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -710,33 +710,44 @@ EXPORT_SYMBOL(nla_find); /** * nla_strlcpy - Copy string attribute payload into a sized buffer - * @dst: where to copy the string to - * @nla: attribute to copy the string from - * @dstsize: size of destination buffer + * @dst: Where to copy the string to. + * @nla: Attribute to copy the string from. + * @dstsize: Size of destination buffer. * * Copies at most dstsize - 1 bytes into the destination buffer. - * The result is always a valid NUL-terminated string. Unlike - * strlcpy the destination buffer is always padded out. + * Unlike strlcpy the destination buffer is always padded out. * - * Returns the length of the source buffer. + * Return: + * * srclen - Returns @nla length (not including the trailing %NUL). + * * -E2BIG - If @dstsize is 0 or greater than U16_MAX or @nla length greater + * than @dstsize. */ -size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize) +ssize_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize) { size_t srclen = nla_len(nla); char *src = nla_data(nla); + ssize_t ret; + size_t len; + + if (dstsize == 0 || WARN_ON_ONCE(dstsize > U16_MAX)) + return -E2BIG; if (srclen > 0 && src[srclen - 1] == '\0') srclen--; - if (dstsize > 0) { - size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen; - - memcpy(dst, src, len); - /* Zero pad end of dst. */ - memset(dst + len, 0, dstsize - len); + if (srclen >= dstsize) { + len = dstsize - 1; + ret = -E2BIG; + } else { + len = srclen; + ret = len; } - return srclen; + memcpy(dst, src, len); + /* Zero pad end of dst. */ + memset(dst + len, 0, dstsize - len); + + return ret; } EXPORT_SYMBOL(nla_strlcpy); |