The branch main has been updated by kp:
URL:
https://cgit.FreeBSD.org/src/commit/?id=76e00c722bee123f902febce7b637ea7afa5e364
commit 76e00c722bee123f902febce7b637ea7afa5e364
Author: Kristof Provost <k...@freebsd.org>
AuthorDate: 2025-01-06 10:39:32 +0000
Commit: Kristof Provost <k...@freebsd.org>
CommitDate: 2025-01-17 16:00:08 +0000
dummymbuf: add 'enlarge'
Teach dummymbuf to replace mbufs with larger ones.
This can be useful for testing for bugs that depend on mbuf layout.
Sponsored by: Rubicon Communications, LLC ("Netgate")
---
share/man/man4/dummymbuf.4 | 4 +++-
sys/net/dummymbuf.c | 34 ++++++++++++++++++++++++++++++++++
2 files changed, 37 insertions(+), 1 deletion(-)
diff --git a/share/man/man4/dummymbuf.4 b/share/man/man4/dummymbuf.4
index 844a7c0565bd..08926d2824c6 100644
--- a/share/man/man4/dummymbuf.4
+++ b/share/man/man4/dummymbuf.4
@@ -26,7 +26,7 @@
.\"
.\" Note: The date here should be updated whenever a non-trivial
.\" change is made to the manual page.
-.Dd August 2, 2024
+.Dd January 6, 2025
.Dt DUMMYMBUF 4
.Os
.Sh NAME
@@ -121,6 +121,8 @@ tail mbuf(s) left empty.
.Pp
As a result, only the layout of a mbuf chain is altered, its content logically
is left intact.
+.It enlarge <number-of-bytes>
+Unconditionally replace the mbuf with an mbuf of the specified size.
.El
.Sh SYSCTL VARIABLES
The following variables are available:
diff --git a/sys/net/dummymbuf.c b/sys/net/dummymbuf.c
index ff566cfb87c3..e88087e1572f 100644
--- a/sys/net/dummymbuf.c
+++ b/sys/net/dummymbuf.c
@@ -209,6 +209,37 @@ bad:
return (NULL);
}
+static struct mbuf *
+dmb_m_enlarge(struct mbuf *m, struct rule *rule)
+{
+ struct mbuf *n;
+ int size;
+
+ size = (int)strtol(rule->opargs, NULL, 10);
+ if (size < 0 || size > MJUM16BYTES)
+ goto bad;
+
+ if (!(m->m_flags & M_PKTHDR))
+ goto bad;
+ if (m->m_pkthdr.len <= 0)
+ return (m);
+
+ if ((n = m_get3(size, M_NOWAIT, MT_DATA, M_PKTHDR)) == NULL)
+ goto bad;
+
+ m_move_pkthdr(n, m);
+ m_copydata(m, 0, m->m_pkthdr.len, n->m_ext.ext_buf);
+ n->m_len = m->m_pkthdr.len;
+
+ n->m_next = m;
+
+ return (n);
+
+bad:
+ m_freem(m);
+ return (NULL);
+}
+
static bool
read_rule(const char **cur, struct rule *rule, bool *eof)
{
@@ -278,6 +309,9 @@ read_rule(const char **cur, struct rule *rule, bool *eof)
if (strstr(*cur, "pull-head") == *cur) {
rule->op = dmb_m_pull_head;
*cur += strlen("pull-head");
+ } else if (strstr(*cur, "enlarge") == *cur) {
+ rule->op = dmb_m_enlarge;
+ *cur += strlen("enlarge");
} else {
return (false);
}
