The branch main has been updated by mjg:
URL:
https://cgit.FreeBSD.org/src/commit/?id=0359e7a5e49f3fa8f9e87923a0830239d3372132
commit 0359e7a5e49f3fa8f9e87923a0830239d3372132
Author: Mateusz Guzik <m...@freebsd.org>
AuthorDate: 2021-11-10 17:15:51 +0000
Commit: Mateusz Guzik <m...@freebsd.org>
CommitDate: 2021-11-12 15:40:28 +0000
net: sprinkle __predict_false in ip_input on error conditions
While here rearrange the RVSP check to inspect proto first and avoid
evaluating V_rsvp in the common case to begin with (most notably avoid
the expensive read).
Reviewed by: glebius
Sponsored by: Rubicon Communications, LLC ("Netgate")
Differential Revision: https://reviews.freebsd.org/D32929
---
sys/netinet/ip_input.c | 27 +++++++++++++++------------
1 file changed, 15 insertions(+), 12 deletions(-)
diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c
index dc122dd62e99..be04e27b8224 100644
--- a/sys/netinet/ip_input.c
+++ b/sys/netinet/ip_input.c
@@ -476,28 +476,31 @@ ip_input(struct mbuf *m)
IPSTAT_INC(ips_total);
- if (m->m_pkthdr.len < sizeof(struct ip))
+ if (__predict_false(m->m_pkthdr.len < sizeof(struct ip)))
goto tooshort;
- if (m->m_len < sizeof (struct ip) &&
- (m = m_pullup(m, sizeof (struct ip))) == NULL) {
- IPSTAT_INC(ips_toosmall);
- return;
+ if (m->m_len < sizeof(struct ip)) {
+ m = m_pullup(m, sizeof(struct ip));
+ if (__predict_false(m == NULL)) {
+ IPSTAT_INC(ips_toosmall);
+ return;
+ }
}
ip = mtod(m, struct ip *);
- if (ip->ip_v != IPVERSION) {
+ if (__predict_false(ip->ip_v != IPVERSION)) {
IPSTAT_INC(ips_badvers);
goto bad;
}
hlen = ip->ip_hl << 2;
- if (hlen < sizeof(struct ip)) { /* minimum header length */
+ if (__predict_false(hlen < sizeof(struct ip))) { /* minimum
header length */
IPSTAT_INC(ips_badhlen);
goto bad;
}
if (hlen > m->m_len) {
- if ((m = m_pullup(m, hlen)) == NULL) {
+ m = m_pullup(m, hlen);
+ if (__predict_false(m == NULL)) {
IPSTAT_INC(ips_badhlen);
return;
}
@@ -525,7 +528,7 @@ ip_input(struct mbuf *m)
sum = in_cksum(m, hlen);
}
}
- if (sum) {
+ if (__predict_false(sum)) {
IPSTAT_INC(ips_badsum);
goto bad;
}
@@ -537,7 +540,7 @@ ip_input(struct mbuf *m)
#endif
ip_len = ntohs(ip->ip_len);
- if (ip_len < hlen) {
+ if (__predict_false(ip_len < hlen)) {
IPSTAT_INC(ips_badlen);
goto bad;
}
@@ -548,7 +551,7 @@ ip_input(struct mbuf *m)
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
- if (m->m_pkthdr.len < ip_len) {
+ if (__predict_false(m->m_pkthdr.len < ip_len)) {
tooshort:
IPSTAT_INC(ips_tooshort);
goto bad;
@@ -650,7 +653,7 @@ passin:
* anywhere else. Also checks if the rsvp daemon is running before
* grabbing the packet.
*/
- if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
+ if (ip->ip_p == IPPROTO_RSVP && V_rsvp_on)
goto ours;
/*
