From: Denis Ovsienko <denis@ovsienko.info>
Date: Mon, 25 Jan 2021 12:51:54 +0000 (+0000)
Subject: OpenFlow 1.0: Simplify the snapend management. [skip ci]
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/6c982c49c695e958f6e881874b7ba1cc447588a0?ds=sidebyside

OpenFlow 1.0: Simplify the snapend management. [skip ci]

As Guy explains it, nd_push_snapend() makes it easy to save and to
restore the snapend from different functions or different invocations
of the same function. In a simple case a local variable and ND_MIN()
do the job just as well without the associated memory management and
error checking.
---

diff --git a/print-openflow-1.0.c b/print-openflow-1.0.c
index 7751f2d9..82a4f0ba 100644
--- a/print-openflow-1.0.c
+++ b/print-openflow-1.0.c
@@ -1025,11 +1025,10 @@ of10_packet_data_print(netdissect_options *ndo,
 	 * what ether_print() needs to decode an Ethernet frame nested in
 	 * the middle of a TCP payload.
 	 */
-	if (!nd_push_snapend(ndo, cp + len))
-		(*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
-		                  "%s: failed to adjust snapend", __func__);
+	const u_char *snapend_save = ndo->ndo_snapend;
+	ndo->ndo_snapend = ND_MIN(cp + len, ndo->ndo_snapend);
 	ether_print(ndo, cp, len, ND_BYTES_AVAILABLE_AFTER(cp), NULL, NULL);
-	nd_pop_packet_info(ndo);
+	ndo->ndo_snapend = snapend_save;
 	ndo->ndo_vflag += 3;
 }