diff options
Diffstat (limited to 'freebsd/contrib/tcpdump/util-print.c')
| -rw-r--r-- | freebsd/contrib/tcpdump/util-print.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/freebsd/contrib/tcpdump/util-print.c b/freebsd/contrib/tcpdump/util-print.c index ef1454a1..49bcfe6c 100644 --- a/freebsd/contrib/tcpdump/util-print.c +++ b/freebsd/contrib/tcpdump/util-print.c @@ -126,10 +126,21 @@ fn_print(netdissect_options *ndo, /* * Print out a null-terminated filename (or other ascii string) from - * a fixed-length buffer. - * If ep is NULL, assume no truncation check is needed. + * a fixed-length field in the packet buffer, or from what remains of + * the packet. + * + * n is the length of the fixed-length field, or the number of bytes + * remaining in the packet based on its on-the-network length. + * + * If ep is non-null, it should point just past the last captured byte + * of the packet, e.g. ndo->ndo_snapend. If ep is NULL, we assume no + * truncation check, other than the checks of the field length/remaining + * packet data length, is needed. + * * Return the number of bytes of string processed, including the - * terminating null, if not truncated. Return 0 if truncated. + * terminating null, if not truncated; as the terminating null is + * included in the count, and as there must be a terminating null, + * this will always be non-zero. Return 0 if truncated. */ u_int fn_printztn(netdissect_options *ndo, @@ -143,7 +154,8 @@ fn_printztn(netdissect_options *ndo, if (n == 0 || (ep != NULL && s >= ep)) { /* * Truncated. This includes "no null before we - * got to the end of the fixed-length buffer". + * got to the end of the fixed-length buffer or + * the end of the packet". * * XXX - BOOTP says "null-terminated", which * means the maximum length of the string, in |