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author | Stephen Gallagher <sgallagh@redhat.com> | 2010-08-25 10:44:14 -0400 |
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committer | Stephen Gallagher <sgallagh@redhat.com> | 2010-10-13 09:49:37 -0400 |
commit | 3ba74ad02d3a20d50c068faa02797fafba105508 (patch) | |
tree | 2ef51784c47b23ed2e80097f1c9b5ac4c320b07d /src/sss_client/common.c | |
parent | 93109c5f1d85c028ce5cf6e31e2249ca90a7f746 (diff) | |
download | sssd-3ba74ad02d3a20d50c068faa02797fafba105508.tar.gz sssd-3ba74ad02d3a20d50c068faa02797fafba105508.tar.bz2 sssd-3ba74ad02d3a20d50c068faa02797fafba105508.zip |
Add utility function sss_strnlen()
This is useful for guaranteeing the size of an input buffer.
Diffstat (limited to 'src/sss_client/common.c')
-rw-r--r-- | src/sss_client/common.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/src/sss_client/common.c b/src/sss_client/common.c index 6b79c783..3bfa8928 100644 --- a/src/sss_client/common.c +++ b/src/sss_client/common.c @@ -761,3 +761,32 @@ const char *ssscli_err2string(int err) return _("Unexpected error while looking for an error description"); } + +/* Return strlen(str) or maxlen, whichever is shorter + * Returns EINVAL if str is NULL, EFBIG if str is longer than maxlen + * _len will return the result + * + * This function is useful for preventing buffer overflow attacks. + */ +errno_t sss_strnlen(const char *str, size_t maxlen, size_t *len) +{ + if (!str) { + return EINVAL; + } + +#if defined __USE_GNU + *len = strnlen(str, maxlen); +#else + *len = 0; + while (*len < maxlen) { + if (str[*len] == '\0') break; + len++; + } +#endif + + if (*len == maxlen && str[*len] != '\0') { + return EFBIG; + } + + return 0; +} |