Add a devmap for XDP_REDIRECT and use it for redirect action.
Signed-off-by: Toshiaki Makita <toshiaki.maki...@gmail.com>
---
net/xdp_flow/umh_bpf.h | 1 +
net/xdp_flow/xdp_flow_kern_bpf.c | 14 +++-
net/xdp_flow/xdp_flow_kern_mod.c | 3 +
net/xdp_flow/xdp_flow_umh.c | 164 +++++++++++++++++++++++++++++++++++++--
4 files changed, 175 insertions(+), 7 deletions(-)
diff --git a/net/xdp_flow/umh_bpf.h b/net/xdp_flow/umh_bpf.h
index 4e4633f..a279d0a1 100644
--- a/net/xdp_flow/umh_bpf.h
+++ b/net/xdp_flow/umh_bpf.h
@@ -4,6 +4,7 @@
#include "msgfmt.h"
+#define MAX_PORTS 65536
#define MAX_FLOWS 1024
#define MAX_FLOW_MASKS 255
#define FLOW_MASKS_TAIL 255
diff --git a/net/xdp_flow/xdp_flow_kern_bpf.c b/net/xdp_flow/xdp_flow_kern_bpf.c
index ceb8a92..8f3d359 100644
--- a/net/xdp_flow/xdp_flow_kern_bpf.c
+++ b/net/xdp_flow/xdp_flow_kern_bpf.c
@@ -22,6 +22,13 @@ struct bpf_map_def SEC("maps") debug_stats = {
.max_entries = 256,
};
+struct bpf_map_def SEC("maps") output_map = {
+ .type = BPF_MAP_TYPE_DEVMAP,
+ .key_size = sizeof(int),
+ .value_size = sizeof(int),
+ .max_entries = MAX_PORTS,
+};
+
struct bpf_map_def SEC("maps") flow_masks_head = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(u32),
@@ -71,10 +78,13 @@ static inline int action_drop(void)
static inline int action_redirect(struct xdp_flow_action *action)
{
+ int tx_port;
+
account_action(XDP_FLOW_ACTION_REDIRECT);
- // TODO: implement this
- return XDP_ABORTED;
+ tx_port = action->ifindex;
+
+ return bpf_redirect_map(&output_map, tx_port, 0);
}
static inline int action_vlan_push(struct xdp_md *ctx,
diff --git a/net/xdp_flow/xdp_flow_kern_mod.c b/net/xdp_flow/xdp_flow_kern_mod.c
index 891b18c..caa4968 100644
--- a/net/xdp_flow/xdp_flow_kern_mod.c
+++ b/net/xdp_flow/xdp_flow_kern_mod.c
@@ -51,6 +51,9 @@ static int xdp_flow_parse_actions(struct xdp_flow_actions
*actions,
action->id = XDP_FLOW_ACTION_DROP;
break;
case FLOW_ACTION_REDIRECT:
+ action->id = XDP_FLOW_ACTION_REDIRECT;
+ action->ifindex = act->dev->ifindex;
+ break;
case FLOW_ACTION_VLAN_PUSH:
case FLOW_ACTION_VLAN_POP:
case FLOW_ACTION_VLAN_MANGLE:
diff --git a/net/xdp_flow/xdp_flow_umh.c b/net/xdp_flow/xdp_flow_umh.c
index 9a4769b..cbb766a 100644
--- a/net/xdp_flow/xdp_flow_umh.c
+++ b/net/xdp_flow/xdp_flow_umh.c
@@ -18,6 +18,7 @@
extern char xdp_flow_bpf_start;
extern char xdp_flow_bpf_end;
int progfile_fd;
+int output_map_fd;
#define zalloc(size) calloc(1, (size))
@@ -40,12 +41,22 @@ struct netdev_info {
struct netdev_info_key key;
struct hlist_node node;
struct bpf_object *obj;
+ int devmap_idx;
int free_slot_top;
int free_slots[MAX_FLOW_MASKS];
};
DEFINE_HASHTABLE(netdev_info_table, 16);
+struct devmap_idx_node {
+ int devmap_idx;
+ struct hlist_node node;
+};
+
+DEFINE_HASHTABLE(devmap_idx_table, 16);
+
+int max_devmap_idx;
+
static int libbpf_err(int err, char *errbuf)
{
libbpf_strerror(err, errbuf, ERRBUF_SIZE);
@@ -90,6 +101,15 @@ static int setup(void)
goto err;
}
+ output_map_fd = bpf_create_map(BPF_MAP_TYPE_DEVMAP, sizeof(int),
+ sizeof(int), MAX_PORTS, 0);
+ if (output_map_fd < 0) {
+ err = -errno;
+ pr_err("map creation for output_map failed: %s\n",
+ strerror(errno));
+ goto err;
+ }
+
return 0;
err:
close(progfile_fd);
@@ -97,10 +117,23 @@ static int setup(void)
return err;
}
-static int load_bpf(int ifindex, struct bpf_object **objp)
+static void delete_output_map_elem(int idx)
+{
+ char errbuf[ERRBUF_SIZE];
+ int err;
+
+ err = bpf_map_delete_elem(output_map_fd, &idx);
+ if (err) {
+ libbpf_err(err, errbuf);
+ pr_warn("Failed to delete idx %d from output_map: %s\n",
+ idx, errbuf);
+ }
+}
+
+static int load_bpf(int ifindex, int devmap_idx, struct bpf_object **objp)
{
int prog_fd, flow_tables_fd, flow_meta_fd, flow_masks_head_fd, err;
- struct bpf_map *flow_tables, *flow_masks_head;
+ struct bpf_map *output_map, *flow_tables, *flow_masks_head;
int zero = 0, flow_masks_tail = FLOW_MASKS_TAIL;
struct bpf_object_open_attr attr = {};
char path[256], errbuf[ERRBUF_SIZE];
@@ -133,6 +166,27 @@ static int load_bpf(int ifindex, struct bpf_object **objp)
bpf_object__for_each_program(prog, obj)
bpf_program__set_type(prog, attr.prog_type);
+ output_map = bpf_object__find_map_by_name(obj, "output_map");
+ if (!output_map) {
+ pr_err("Cannot find output_map\n");
+ err = -ENOENT;
+ goto err_obj;
+ }
+
+ err = bpf_map__reuse_fd(output_map, output_map_fd);
+ if (err) {
+ err = libbpf_err(err, errbuf);
+ pr_err("Failed to reuse output_map fd: %s\n", errbuf);
+ goto err_obj;
+ }
+
+ if (bpf_map_update_elem(output_map_fd, &devmap_idx, &ifindex, 0)) {
+ err = -errno;
+ pr_err("Failed to insert idx %d if %d into output_map: %s\n",
+ devmap_idx, ifindex, strerror(errno));
+ goto err_obj;
+ }
+
flow_meta_fd = bpf_create_map(BPF_MAP_TYPE_HASH,
sizeof(struct xdp_flow_key),
sizeof(struct xdp_flow_actions),
@@ -222,6 +276,8 @@ static int load_bpf(int ifindex, struct bpf_object **objp)
return prog_fd;
err:
+ delete_output_map_elem(devmap_idx);
+err_obj:
bpf_object__close(obj);
return err;
}
@@ -272,6 +328,56 @@ static struct netdev_info *get_netdev_info(const struct
mbox_request *req)
return netdev_info;
}
+static struct devmap_idx_node *find_devmap_idx(int devmap_idx)
+{
+ struct devmap_idx_node *node;
+
+ hash_for_each_possible(devmap_idx_table, node, node, devmap_idx) {
+ if (node->devmap_idx == devmap_idx)
+ return node;
+ }
+
+ return NULL;
+}
+
+static int get_new_devmap_idx(void)
+{
+ int offset;
+
+ for (offset = 0; offset < MAX_PORTS; offset++) {
+ int devmap_idx = max_devmap_idx++;
+
+ if (max_devmap_idx >= MAX_PORTS)
+ max_devmap_idx -= MAX_PORTS;
+
+ if (!find_devmap_idx(devmap_idx)) {
+ struct devmap_idx_node *node;
+
+ node = malloc(sizeof(*node));
+ if (!node) {
+ pr_err("malloc for devmap_idx failed\n");
+ return -ENOMEM;
+ }
+ node->devmap_idx = devmap_idx;
+ hash_add(devmap_idx_table, &node->node, devmap_idx);
+
+ return devmap_idx;
+ }
+ }
+
+ return -ENOSPC;
+}
+
+static void delete_devmap_idx(int devmap_idx)
+{
+ struct devmap_idx_node *node = find_devmap_idx(devmap_idx);
+
+ if (node) {
+ hash_del(&node->node);
+ free(node);
+ }
+}
+
static void init_flow_masks_free_slot(struct netdev_info *netdev_info)
{
int i;
@@ -325,11 +431,11 @@ static void delete_flow_masks_free_slot(struct
netdev_info *netdev_info,
static int handle_load(const struct mbox_request *req, __u32 *prog_id)
{
+ int err, prog_fd, devmap_idx = -1;
struct netdev_info *netdev_info;
struct bpf_prog_info info = {};
struct netdev_info_key key;
__u32 len = sizeof(info);
- int err, prog_fd;
err = get_netdev_info_key(req, &key);
if (err)
@@ -346,12 +452,19 @@ static int handle_load(const struct mbox_request *req,
__u32 *prog_id)
}
netdev_info->key.ifindex = key.ifindex;
+ devmap_idx = get_new_devmap_idx();
+ if (devmap_idx < 0) {
+ err = devmap_idx;
+ goto err_netdev_info;
+ }
+ netdev_info->devmap_idx = devmap_idx;
+
init_flow_masks_free_slot(netdev_info);
- prog_fd = load_bpf(req->ifindex, &netdev_info->obj);
+ prog_fd = load_bpf(req->ifindex, devmap_idx, &netdev_info->obj);
if (prog_fd < 0) {
err = prog_fd;
- goto err_netdev_info;
+ goto err_devmap_idx;
}
err = bpf_obj_get_info_by_fd(prog_fd, &info, &len);
@@ -366,6 +479,8 @@ static int handle_load(const struct mbox_request *req,
__u32 *prog_id)
return 0;
err_obj:
bpf_object__close(netdev_info->obj);
+err_devmap_idx:
+ delete_devmap_idx(devmap_idx);
err_netdev_info:
free(netdev_info);
@@ -382,12 +497,45 @@ static int handle_unload(const struct mbox_request *req)
hash_del(&netdev_info->node);
bpf_object__close(netdev_info->obj);
+ delete_output_map_elem(netdev_info->devmap_idx);
+ delete_devmap_idx(netdev_info->devmap_idx);
free(netdev_info);
pr_debug("XDP program for if %d was closed\n", req->ifindex);
return 0;
}
+static int convert_ifindex_to_devmap_idx(struct mbox_request *req)
+{
+ int i;
+
+ for (i = 0; i < req->flow.actions.num_actions; i++) {
+ struct xdp_flow_action *action = &req->flow.actions.actions[i];
+
+ if (action->id == XDP_FLOW_ACTION_REDIRECT) {
+ struct netdev_info *netdev_info;
+ struct netdev_info_key key;
+ int err;
+
+ err = get_netdev_info_key(req, &key);
+ if (err)
+ return err;
+ key.ifindex = action->ifindex;
+
+ netdev_info = find_netdev_info(&key);
+ if (!netdev_info) {
+ pr_err("Cannot redirect to ifindex %d. Please
setup xdp_flow on ifindex %d in advance.\n",
+ key.ifindex, key.ifindex);
+ return -ENOENT;
+ }
+
+ action->ifindex = netdev_info->devmap_idx;
+ }
+ }
+
+ return 0;
+}
+
static int get_table_fd(const struct netdev_info *netdev_info,
const char *table_name)
{
@@ -784,6 +932,11 @@ static int handle_replace(struct mbox_request *req)
if (IS_ERR(netdev_info))
return PTR_ERR(netdev_info);
+ /* TODO: Use XDP_TX for redirect action when possible */
+ err = convert_ifindex_to_devmap_idx(req);
+ if (err)
+ return err;
+
err = flow_table_insert_elem(netdev_info, &req->flow);
if (err)
return err;
@@ -875,6 +1028,7 @@ int main(void)
return -1;
loop();
close(progfile_fd);
+ close(output_map_fd);
return 0;
}
--
1.8.3.1
