git: 86a6393a7d67 - main - ng_bridge: allow to automatically assign numbers to new hooks
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Date: Mon, 08 Apr 2024 17:48:45 UTC
The branch main has been updated by glebius:
URL: https://cgit.FreeBSD.org/src/commit/?id=86a6393a7d6766875a9e03daa0273a2e55faacdd
commit 86a6393a7d6766875a9e03daa0273a2e55faacdd
Author: David Marker <dave@freedave.net>
AuthorDate: 2024-04-08 17:48:22 +0000
Commit: Gleb Smirnoff <glebius@FreeBSD.org>
CommitDate: 2024-04-08 17:48:22 +0000
ng_bridge: allow to automatically assign numbers to new hooks
This will allow a userland machinery that orchestrates a bridge (e.g. a
jail or vm manager) to not double the number allocation logic. See bug
278130 for longer description and examples.
Reviewed by: glebius, afedorov
Differential Revision: https://reviews.freebsd.org/D44615
PR: 278130
---
share/man/man4/ng_bridge.4 | 13 +++++-
sys/netgraph/ng_bridge.c | 104 +++++++++++++++++++++++++++++++++++----------
2 files changed, 93 insertions(+), 24 deletions(-)
diff --git a/share/man/man4/ng_bridge.4 b/share/man/man4/ng_bridge.4
index 45bc6b3cb6a7..7e5b4e0bd0ca 100644
--- a/share/man/man4/ng_bridge.4
+++ b/share/man/man4/ng_bridge.4
@@ -32,7 +32,7 @@
.\"
.\" Author: Archie Cobbs <archie@FreeBSD.org>
.\"
-.Dd May 13, 2021
+.Dd April 8, 2024
.Dt NG_BRIDGE 4
.Os
.Sh NAME
@@ -108,6 +108,17 @@ Frames with unknown MACs are always sent out to
.Ar uplink
hooks, so no functionality is lost.
.Pp
+The
+.Ar linkX
+and
+.Ar uplinkX
+hook numbers can be autoassigned.
+If a new hook name was specified as
+.Ar link
+or
+.Ar uplink
+the node will append lowest available valid number to the name of the new hook.
+.Pp
Frames with unknown destination MAC addresses are replicated to any
available hook, unless the first connected hook is an
.Ar uplink
diff --git a/sys/netgraph/ng_bridge.c b/sys/netgraph/ng_bridge.c
index ebe811acc5b5..70bc581f8570 100644
--- a/sys/netgraph/ng_bridge.c
+++ b/sys/netgraph/ng_bridge.c
@@ -124,6 +124,8 @@ struct ng_bridge_private {
unsigned int persistent : 1, /* can exist w/o hooks */
sendUnknown : 1;/* links receive unknowns by default */
struct callout timer; /* one second periodic timer */
+ struct unrhdr *linkUnit; /* link unit number allocator */
+ struct unrhdr *uplinkUnit; /* uplink unit number allocator */
};
typedef struct ng_bridge_private *priv_p;
typedef struct ng_bridge_private const *priv_cp; /* read only access */
@@ -140,6 +142,21 @@ struct ng_bridge_host {
/* Hash table bucket declaration */
SLIST_HEAD(ng_bridge_bucket, ng_bridge_host);
+/* [up]link prefix matching */
+struct ng_link_prefix {
+ const char * const prefix;
+ size_t len;
+};
+
+static const struct ng_link_prefix link_pfx = {
+ .prefix = NG_BRIDGE_HOOK_LINK_PREFIX,
+ .len = sizeof(NG_BRIDGE_HOOK_LINK_PREFIX) - 1,
+};
+static const struct ng_link_prefix uplink_pfx = {
+ .prefix = NG_BRIDGE_HOOK_UPLINK_PREFIX,
+ .len = sizeof(NG_BRIDGE_HOOK_UPLINK_PREFIX) - 1,
+};
+
/* Netgraph node methods */
static ng_constructor_t ng_bridge_constructor;
static ng_rcvmsg_t ng_bridge_rcvmsg;
@@ -149,6 +166,7 @@ static ng_rcvdata_t ng_bridge_rcvdata;
static ng_disconnect_t ng_bridge_disconnect;
/* Other internal functions */
+static const struct ng_link_prefix *ng_get_link_prefix(const char *name);
static void ng_bridge_free_link(link_p link);
static struct ng_bridge_host *ng_bridge_get(priv_cp priv, const u_char *addr);
static int ng_bridge_put(priv_p priv, const u_char *addr, link_p link);
@@ -350,6 +368,10 @@ ng_bridge_constructor(node_p node)
NG_NODE_SET_PRIVATE(node, priv);
priv->node = node;
+ /* Allocators for links. Historically "uplink0" is not allowed. */
+ priv->linkUnit = new_unrhdr(0, INT_MAX, NULL);
+ priv->uplinkUnit = new_unrhdr(1, INT_MAX, NULL);
+
/* Start timer; timer is always running while node is alive */
ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
@@ -364,36 +386,50 @@ static int
ng_bridge_newhook(node_p node, hook_p hook, const char *name)
{
const priv_p priv = NG_NODE_PRIVATE(node);
- char linkName[NG_HOOKSIZ];
- u_int32_t linkNum;
link_p link;
- const char *prefix = NG_BRIDGE_HOOK_LINK_PREFIX;
bool isUplink;
+ uint32_t linkNum;
+ struct unrhdr *unit;
+
+ const struct ng_link_prefix *pfx = ng_get_link_prefix(name);
+ if (pfx == NULL)
+ return (EINVAL); /* not a valid prefix */
+
+ isUplink = (pfx == &uplink_pfx);
+ unit = isUplink ? priv->uplinkUnit : priv->linkUnit;
+
+ if (strlen(name) > pfx->len) { /* given number */
+ char linkName[NG_HOOKSIZ];
+ int rvnum __diagused;
+
+ linkNum = strtoul(name + pfx->len, NULL, 10);
+ /* Validate by comparing against the reconstucted name. */
+ snprintf(linkName, sizeof(linkName), "%s%u", pfx->prefix,
+ linkNum);
+ if (strcmp(linkName, name) != 0)
+ return (EINVAL);
+ if (linkNum == 0 && isUplink)
+ return (EINVAL);
+ rvnum = alloc_unr_specific(unit, linkNum);
+ MPASS(rvnum == linkNum);
+ } else {
+ /* auto-assign and update hook name */
+ linkNum = alloc_unr(unit);
+ MPASS(linkNum != -1);
+ snprintf(NG_HOOK_NAME(hook), NG_HOOKSIZ, "%s%u", pfx->prefix,
+ linkNum);
+ }
- /* Check for a link hook */
- if (strlen(name) <= strlen(prefix))
- return (EINVAL); /* Unknown hook name */
-
- isUplink = (name[0] == 'u');
- if (isUplink)
- prefix = NG_BRIDGE_HOOK_UPLINK_PREFIX;
-
- /* primitive parsing */
- linkNum = strtoul(name + strlen(prefix), NULL, 10);
- /* validation by comparing against the reconstucted name */
- snprintf(linkName, sizeof(linkName), "%s%u", prefix, linkNum);
- if (strcmp(linkName, name) != 0)
- return (EINVAL);
-
- if (linkNum == 0 && isUplink)
- return (EINVAL);
-
- if(NG_PEER_NODE(hook) == node)
+ if (NG_PEER_NODE(hook) == node) {
+ free_unr(unit, linkNum);
return (ELOOP);
+ }
link = malloc(sizeof(*link), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
- if (link == NULL)
+ if (link == NULL) {
+ free_unr(unit, linkNum);
return (ENOMEM);
+ }
#define NG_BRIDGE_COUNTER_ALLOC(f) do { \
link->stats.f = counter_u64_alloc(M_NOWAIT); \
@@ -431,6 +467,7 @@ ng_bridge_newhook(node_p node, hook_p hook, const char *name)
return (0);
nomem:
+ free_unr(unit, linkNum);
ng_bridge_free_link(link);
return (ENOMEM);
}
@@ -914,6 +951,8 @@ ng_bridge_shutdown(node_p node)
("%s: numLinks=%d numHosts=%d",
__func__, priv->numLinks, priv->numHosts));
ng_uncallout(&priv->timer, node);
+ delete_unrhdr(priv->linkUnit);
+ delete_unrhdr(priv->uplinkUnit);
NG_NODE_SET_PRIVATE(node, NULL);
NG_NODE_UNREF(node);
free(priv->tab, M_NETGRAPH_BRIDGE);
@@ -927,8 +966,11 @@ ng_bridge_shutdown(node_p node)
static int
ng_bridge_disconnect(hook_p hook)
{
+ char *name = NG_HOOK_NAME(hook);
const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
link_p link = NG_HOOK_PRIVATE(hook);
+ const struct ng_link_prefix *pfx = ng_get_link_prefix(name);
+ uint32_t linkNum;
/* Remove all hosts associated with this link */
ng_bridge_remove_hosts(priv, link);
@@ -937,6 +979,9 @@ ng_bridge_disconnect(hook_p hook)
ng_bridge_free_link(link);
priv->numLinks--;
+ linkNum = strtoul(name + pfx->len, NULL, 10);
+ free_unr(pfx == &link_pfx ? priv->linkUnit: priv->uplinkUnit, linkNum);
+
/* If no more hooks, go away */
if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
@@ -1095,6 +1140,19 @@ ng_bridge_rehash(priv_p priv)
MISC FUNCTIONS
******************************************************************/
+static const struct ng_link_prefix *
+ng_get_link_prefix(const char *name)
+{
+ static const struct ng_link_prefix *pfxs[] =
+ { &link_pfx, &uplink_pfx, };
+
+ for (u_int i = 0; i < nitems(pfxs); i++)
+ if (strncmp(pfxs[i]->prefix, name, pfxs[i]->len) == 0)
+ return (pfxs[i]);
+
+ return (NULL);
+}
+
/*
* Remove all hosts associated with a specific link from the hashtable.
* If linkNum == -1, then remove all hosts in the table.