The branch main has been updated by tuexen:
URL:
https://cgit.FreeBSD.org/src/commit/?id=e0b080f850cc0418353cc196cbfe81075cf76661
commit e0b080f850cc0418353cc196cbfe81075cf76661
Author: Michael Tuexen <tue...@freebsd.org>
AuthorDate: 2024-07-21 13:06:10 +0000
Commit: Michael Tuexen <tue...@freebsd.org>
CommitDate: 2024-07-21 13:06:10 +0000
tcp: mark TCP stacks which can serve as a default stack
Allow a TCP function block (tfb) to become the default stack only if
tfb->tfb_flags has the TCP_FUNC_DEFAULT_OK flags set. This allows a
TCP function block, that is not suitable as a default function block
to ensure that it is not set as the default via sysctl. In this case
sysctl would return EINVAL.
Reviewed by: gallatin, Peter Lei
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D45419
---
sys/netinet/tcp_stacks/bbr.c | 2 +-
sys/netinet/tcp_stacks/rack.c | 2 +-
sys/netinet/tcp_subr.c | 5 +++++
sys/netinet/tcp_var.h | 1 +
4 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/sys/netinet/tcp_stacks/bbr.c b/sys/netinet/tcp_stacks/bbr.c
index 445ba064b316..cf64451f0c87 100644
--- a/sys/netinet/tcp_stacks/bbr.c
+++ b/sys/netinet/tcp_stacks/bbr.c
@@ -14181,7 +14181,7 @@ struct tcp_function_block __tcp_bbr = {
.tfb_tcp_mtu_chg = bbr_mtu_chg,
.tfb_pru_options = bbr_pru_options,
.tfb_switch_failed = bbr_switch_failed,
- .tfb_flags = TCP_FUNC_OUTPUT_CANDROP,
+ .tfb_flags = TCP_FUNC_OUTPUT_CANDROP | TCP_FUNC_DEFAULT_OK,
};
/*
diff --git a/sys/netinet/tcp_stacks/rack.c b/sys/netinet/tcp_stacks/rack.c
index bd7583d3843a..44ddfac2a6ca 100644
--- a/sys/netinet/tcp_stacks/rack.c
+++ b/sys/netinet/tcp_stacks/rack.c
@@ -25289,7 +25289,7 @@ static struct tcp_function_block __tcp_rack = {
.tfb_compute_pipe = rack_compute_pipe,
.tfb_stack_info = rack_stack_information,
.tfb_inherit = rack_inherit,
- .tfb_flags = TCP_FUNC_OUTPUT_CANDROP,
+ .tfb_flags = TCP_FUNC_OUTPUT_CANDROP | TCP_FUNC_DEFAULT_OK,
};
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index 6dc8e0c1c46e..42d29d64e09f 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -359,6 +359,7 @@ static struct tcp_function_block tcp_def_funcblk = {
.tfb_tcp_fb_init = tcp_default_fb_init,
.tfb_tcp_fb_fini = tcp_default_fb_fini,
.tfb_switch_failed = tcp_default_switch_failed,
+ .tfb_flags = TCP_FUNC_DEFAULT_OK,
};
static int tcp_fb_cnt = 0;
@@ -676,6 +677,10 @@ sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS)
error = ENOENT;
goto done;
}
+ if ((blk->tfb_flags & TCP_FUNC_DEFAULT_OK) == 0) {
+ error = EINVAL;
+ goto done;
+ }
V_tcp_func_set_ptr = blk;
done:
rw_wunlock(&tcp_function_lock);
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index 099fb32ee613..52fd0f181e01 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -540,6 +540,7 @@ typedef enum {
/* Flags for tcp functions */
#define TCP_FUNC_BEING_REMOVED 0x01 /* Can no longer be referenced
*/
#define TCP_FUNC_OUTPUT_CANDROP 0x02 /* tfb_tcp_output may ask
tcp_drop */
+#define TCP_FUNC_DEFAULT_OK 0x04 /* Can be used as default */
/**
* tfb_tcp_handoff_ok is a mandatory function allowing
