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Diffstat (limited to 'tools/testing/selftests/net/lib/xdp_native.bpf.c')
-rw-r--r--tools/testing/selftests/net/lib/xdp_native.bpf.c621
1 files changed, 621 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/lib/xdp_native.bpf.c b/tools/testing/selftests/net/lib/xdp_native.bpf.c
new file mode 100644
index 000000000000..521ba38f2ddd
--- /dev/null
+++ b/tools/testing/selftests/net/lib/xdp_native.bpf.c
@@ -0,0 +1,621 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stddef.h>
+#include <linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/udp.h>
+#include <bpf/bpf_endian.h>
+#include <bpf/bpf_helpers.h>
+
+#define MAX_ADJST_OFFSET 256
+#define MAX_PAYLOAD_LEN 5000
+#define MAX_HDR_LEN 64
+
+enum {
+ XDP_MODE = 0,
+ XDP_PORT = 1,
+ XDP_ADJST_OFFSET = 2,
+ XDP_ADJST_TAG = 3,
+} xdp_map_setup_keys;
+
+enum {
+ XDP_MODE_PASS = 0,
+ XDP_MODE_DROP = 1,
+ XDP_MODE_TX = 2,
+ XDP_MODE_TAIL_ADJST = 3,
+ XDP_MODE_HEAD_ADJST = 4,
+} xdp_map_modes;
+
+enum {
+ STATS_RX = 0,
+ STATS_PASS = 1,
+ STATS_DROP = 2,
+ STATS_TX = 3,
+ STATS_ABORT = 4,
+} xdp_stats;
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, 5);
+ __type(key, __u32);
+ __type(value, __s32);
+} map_xdp_setup SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, 5);
+ __type(key, __u32);
+ __type(value, __u64);
+} map_xdp_stats SEC(".maps");
+
+static __u32 min(__u32 a, __u32 b)
+{
+ return a < b ? a : b;
+}
+
+static void record_stats(struct xdp_md *ctx, __u32 stat_type)
+{
+ __u64 *count;
+
+ count = bpf_map_lookup_elem(&map_xdp_stats, &stat_type);
+
+ if (count)
+ __sync_fetch_and_add(count, 1);
+}
+
+static struct udphdr *filter_udphdr(struct xdp_md *ctx, __u16 port)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct udphdr *udph = NULL;
+ struct ethhdr *eth = data;
+
+ if (data + sizeof(*eth) > data_end)
+ return NULL;
+
+ if (eth->h_proto == bpf_htons(ETH_P_IP)) {
+ struct iphdr *iph = data + sizeof(*eth);
+
+ if (iph + 1 > (struct iphdr *)data_end ||
+ iph->protocol != IPPROTO_UDP)
+ return NULL;
+
+ udph = (void *)eth + sizeof(*iph) + sizeof(*eth);
+ } else if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
+ struct ipv6hdr *ipv6h = data + sizeof(*eth);
+
+ if (ipv6h + 1 > (struct ipv6hdr *)data_end ||
+ ipv6h->nexthdr != IPPROTO_UDP)
+ return NULL;
+
+ udph = (void *)eth + sizeof(*ipv6h) + sizeof(*eth);
+ } else {
+ return NULL;
+ }
+
+ if (udph + 1 > (struct udphdr *)data_end)
+ return NULL;
+
+ if (udph->dest != bpf_htons(port))
+ return NULL;
+
+ record_stats(ctx, STATS_RX);
+
+ return udph;
+}
+
+static int xdp_mode_pass(struct xdp_md *ctx, __u16 port)
+{
+ struct udphdr *udph = NULL;
+
+ udph = filter_udphdr(ctx, port);
+ if (!udph)
+ return XDP_PASS;
+
+ record_stats(ctx, STATS_PASS);
+
+ return XDP_PASS;
+}
+
+static int xdp_mode_drop_handler(struct xdp_md *ctx, __u16 port)
+{
+ struct udphdr *udph = NULL;
+
+ udph = filter_udphdr(ctx, port);
+ if (!udph)
+ return XDP_PASS;
+
+ record_stats(ctx, STATS_DROP);
+
+ return XDP_DROP;
+}
+
+static void swap_machdr(void *data)
+{
+ struct ethhdr *eth = data;
+ __u8 tmp_mac[ETH_ALEN];
+
+ __builtin_memcpy(tmp_mac, eth->h_source, ETH_ALEN);
+ __builtin_memcpy(eth->h_source, eth->h_dest, ETH_ALEN);
+ __builtin_memcpy(eth->h_dest, tmp_mac, ETH_ALEN);
+}
+
+static int xdp_mode_tx_handler(struct xdp_md *ctx, __u16 port)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct udphdr *udph = NULL;
+ struct ethhdr *eth = data;
+
+ if (data + sizeof(*eth) > data_end)
+ return XDP_PASS;
+
+ if (eth->h_proto == bpf_htons(ETH_P_IP)) {
+ struct iphdr *iph = data + sizeof(*eth);
+ __be32 tmp_ip = iph->saddr;
+
+ if (iph + 1 > (struct iphdr *)data_end ||
+ iph->protocol != IPPROTO_UDP)
+ return XDP_PASS;
+
+ udph = data + sizeof(*iph) + sizeof(*eth);
+
+ if (udph + 1 > (struct udphdr *)data_end)
+ return XDP_PASS;
+ if (udph->dest != bpf_htons(port))
+ return XDP_PASS;
+
+ record_stats(ctx, STATS_RX);
+ swap_machdr((void *)eth);
+
+ iph->saddr = iph->daddr;
+ iph->daddr = tmp_ip;
+
+ record_stats(ctx, STATS_TX);
+
+ return XDP_TX;
+
+ } else if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
+ struct ipv6hdr *ipv6h = data + sizeof(*eth);
+ struct in6_addr tmp_ipv6;
+
+ if (ipv6h + 1 > (struct ipv6hdr *)data_end ||
+ ipv6h->nexthdr != IPPROTO_UDP)
+ return XDP_PASS;
+
+ udph = data + sizeof(*ipv6h) + sizeof(*eth);
+
+ if (udph + 1 > (struct udphdr *)data_end)
+ return XDP_PASS;
+ if (udph->dest != bpf_htons(port))
+ return XDP_PASS;
+
+ record_stats(ctx, STATS_RX);
+ swap_machdr((void *)eth);
+
+ __builtin_memcpy(&tmp_ipv6, &ipv6h->saddr, sizeof(tmp_ipv6));
+ __builtin_memcpy(&ipv6h->saddr, &ipv6h->daddr,
+ sizeof(tmp_ipv6));
+ __builtin_memcpy(&ipv6h->daddr, &tmp_ipv6, sizeof(tmp_ipv6));
+
+ record_stats(ctx, STATS_TX);
+
+ return XDP_TX;
+ }
+
+ return XDP_PASS;
+}
+
+static void *update_pkt(struct xdp_md *ctx, __s16 offset, __u32 *udp_csum)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct udphdr *udph = NULL;
+ struct ethhdr *eth = data;
+ __u32 len, len_new;
+
+ if (data + sizeof(*eth) > data_end)
+ return NULL;
+
+ if (eth->h_proto == bpf_htons(ETH_P_IP)) {
+ struct iphdr *iph = data + sizeof(*eth);
+ __u16 total_len;
+
+ if (iph + 1 > (struct iphdr *)data_end)
+ return NULL;
+
+ iph->tot_len = bpf_htons(bpf_ntohs(iph->tot_len) + offset);
+
+ udph = (void *)eth + sizeof(*iph) + sizeof(*eth);
+ if (!udph || udph + 1 > (struct udphdr *)data_end)
+ return NULL;
+
+ len_new = bpf_htons(bpf_ntohs(udph->len) + offset);
+ } else if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
+ struct ipv6hdr *ipv6h = data + sizeof(*eth);
+ __u16 payload_len;
+
+ if (ipv6h + 1 > (struct ipv6hdr *)data_end)
+ return NULL;
+
+ udph = (void *)eth + sizeof(*ipv6h) + sizeof(*eth);
+ if (!udph || udph + 1 > (struct udphdr *)data_end)
+ return NULL;
+
+ *udp_csum = ~((__u32)udph->check);
+
+ len = ipv6h->payload_len;
+ len_new = bpf_htons(bpf_ntohs(len) + offset);
+ ipv6h->payload_len = len_new;
+
+ *udp_csum = bpf_csum_diff(&len, sizeof(len), &len_new,
+ sizeof(len_new), *udp_csum);
+
+ len = udph->len;
+ len_new = bpf_htons(bpf_ntohs(udph->len) + offset);
+ *udp_csum = bpf_csum_diff(&len, sizeof(len), &len_new,
+ sizeof(len_new), *udp_csum);
+ } else {
+ return NULL;
+ }
+
+ udph->len = len_new;
+
+ return udph;
+}
+
+static __u16 csum_fold_helper(__u32 csum)
+{
+ return ~((csum & 0xffff) + (csum >> 16)) ? : 0xffff;
+}
+
+static int xdp_adjst_tail_shrnk_data(struct xdp_md *ctx, __u16 offset,
+ __u32 hdr_len)
+{
+ char tmp_buff[MAX_ADJST_OFFSET];
+ __u32 buff_pos, udp_csum = 0;
+ struct udphdr *udph = NULL;
+ __u32 buff_len;
+
+ udph = update_pkt(ctx, 0 - offset, &udp_csum);
+ if (!udph)
+ return -1;
+
+ buff_len = bpf_xdp_get_buff_len(ctx);
+
+ offset = (offset & 0x1ff) >= MAX_ADJST_OFFSET ? MAX_ADJST_OFFSET :
+ offset & 0xff;
+ if (offset == 0)
+ return -1;
+
+ /* Make sure we have enough data to avoid eating the header */
+ if (buff_len - offset < hdr_len)
+ return -1;
+
+ buff_pos = buff_len - offset;
+ if (bpf_xdp_load_bytes(ctx, buff_pos, tmp_buff, offset) < 0)
+ return -1;
+
+ udp_csum = bpf_csum_diff((__be32 *)tmp_buff, offset, 0, 0, udp_csum);
+ udph->check = (__u16)csum_fold_helper(udp_csum);
+
+ if (bpf_xdp_adjust_tail(ctx, 0 - offset) < 0)
+ return -1;
+
+ return 0;
+}
+
+static int xdp_adjst_tail_grow_data(struct xdp_md *ctx, __u16 offset)
+{
+ char tmp_buff[MAX_ADJST_OFFSET];
+ __u32 buff_pos, udp_csum = 0;
+ __u32 buff_len, hdr_len, key;
+ struct udphdr *udph;
+ __s32 *val;
+ __u8 tag;
+
+ /* Proceed to update the packet headers before attempting to adjuste
+ * the tail. Once the tail is adjusted we lose access to the offset
+ * amount of data at the end of the packet which is crucial to update
+ * the checksum.
+ * Since any failure beyond this would abort the packet, we should
+ * not worry about passing a packet up the stack with wrong headers
+ */
+ udph = update_pkt(ctx, offset, &udp_csum);
+ if (!udph)
+ return -1;
+
+ key = XDP_ADJST_TAG;
+ val = bpf_map_lookup_elem(&map_xdp_setup, &key);
+ if (!val)
+ return -1;
+
+ tag = (__u8)(*val);
+
+ for (int i = 0; i < MAX_ADJST_OFFSET; i++)
+ __builtin_memcpy(&tmp_buff[i], &tag, 1);
+
+ offset = (offset & 0x1ff) >= MAX_ADJST_OFFSET ? MAX_ADJST_OFFSET :
+ offset & 0xff;
+ if (offset == 0)
+ return -1;
+
+ udp_csum = bpf_csum_diff(0, 0, (__be32 *)tmp_buff, offset, udp_csum);
+ udph->check = (__u16)csum_fold_helper(udp_csum);
+
+ buff_len = bpf_xdp_get_buff_len(ctx);
+
+ if (bpf_xdp_adjust_tail(ctx, offset) < 0) {
+ bpf_printk("Failed to adjust tail\n");
+ return -1;
+ }
+
+ if (bpf_xdp_store_bytes(ctx, buff_len, tmp_buff, offset) < 0)
+ return -1;
+
+ return 0;
+}
+
+static int xdp_adjst_tail(struct xdp_md *ctx, __u16 port)
+{
+ void *data = (void *)(long)ctx->data;
+ struct udphdr *udph = NULL;
+ __s32 *adjust_offset, *val;
+ __u32 key, hdr_len;
+ void *offset_ptr;
+ __u8 tag;
+ int ret;
+
+ udph = filter_udphdr(ctx, port);
+ if (!udph)
+ return XDP_PASS;
+
+ hdr_len = (void *)udph - data + sizeof(struct udphdr);
+ key = XDP_ADJST_OFFSET;
+ adjust_offset = bpf_map_lookup_elem(&map_xdp_setup, &key);
+ if (!adjust_offset)
+ return XDP_PASS;
+
+ if (*adjust_offset < 0)
+ ret = xdp_adjst_tail_shrnk_data(ctx,
+ (__u16)(0 - *adjust_offset),
+ hdr_len);
+ else
+ ret = xdp_adjst_tail_grow_data(ctx, (__u16)(*adjust_offset));
+ if (ret)
+ goto abort_pkt;
+
+ record_stats(ctx, STATS_PASS);
+ return XDP_PASS;
+
+abort_pkt:
+ record_stats(ctx, STATS_ABORT);
+ return XDP_ABORTED;
+}
+
+static int xdp_adjst_head_shrnk_data(struct xdp_md *ctx, __u64 hdr_len,
+ __u32 offset)
+{
+ char tmp_buff[MAX_ADJST_OFFSET];
+ struct udphdr *udph;
+ void *offset_ptr;
+ __u32 udp_csum = 0;
+
+ /* Update the length information in the IP and UDP headers before
+ * adjusting the headroom. This simplifies accessing the relevant
+ * fields in the IP and UDP headers for fragmented packets. Any
+ * failure beyond this point will result in the packet being aborted,
+ * so we don't need to worry about incorrect length information for
+ * passed packets.
+ */
+ udph = update_pkt(ctx, (__s16)(0 - offset), &udp_csum);
+ if (!udph)
+ return -1;
+
+ offset = (offset & 0x1ff) >= MAX_ADJST_OFFSET ? MAX_ADJST_OFFSET :
+ offset & 0xff;
+ if (offset == 0)
+ return -1;
+
+ if (bpf_xdp_load_bytes(ctx, hdr_len, tmp_buff, offset) < 0)
+ return -1;
+
+ udp_csum = bpf_csum_diff((__be32 *)tmp_buff, offset, 0, 0, udp_csum);
+
+ udph->check = (__u16)csum_fold_helper(udp_csum);
+
+ if (bpf_xdp_load_bytes(ctx, 0, tmp_buff, MAX_ADJST_OFFSET) < 0)
+ return -1;
+
+ if (bpf_xdp_adjust_head(ctx, offset) < 0)
+ return -1;
+
+ if (offset > MAX_ADJST_OFFSET)
+ return -1;
+
+ if (hdr_len > MAX_ADJST_OFFSET || hdr_len == 0)
+ return -1;
+
+ /* Added here to handle clang complain about negative value */
+ hdr_len = hdr_len & 0xff;
+
+ if (hdr_len == 0)
+ return -1;
+
+ if (bpf_xdp_store_bytes(ctx, 0, tmp_buff, hdr_len) < 0)
+ return -1;
+
+ return 0;
+}
+
+static int xdp_adjst_head_grow_data(struct xdp_md *ctx, __u64 hdr_len,
+ __u32 offset)
+{
+ char hdr_buff[MAX_HDR_LEN];
+ char data_buff[MAX_ADJST_OFFSET];
+ void *offset_ptr;
+ __s32 *val;
+ __u32 key;
+ __u8 tag;
+ __u32 udp_csum = 0;
+ struct udphdr *udph;
+
+ udph = update_pkt(ctx, (__s16)(offset), &udp_csum);
+ if (!udph)
+ return -1;
+
+ key = XDP_ADJST_TAG;
+ val = bpf_map_lookup_elem(&map_xdp_setup, &key);
+ if (!val)
+ return -1;
+
+ tag = (__u8)(*val);
+ for (int i = 0; i < MAX_ADJST_OFFSET; i++)
+ __builtin_memcpy(&data_buff[i], &tag, 1);
+
+ offset = (offset & 0x1ff) >= MAX_ADJST_OFFSET ? MAX_ADJST_OFFSET :
+ offset & 0xff;
+ if (offset == 0)
+ return -1;
+
+ udp_csum = bpf_csum_diff(0, 0, (__be32 *)data_buff, offset, udp_csum);
+ udph->check = (__u16)csum_fold_helper(udp_csum);
+
+ if (hdr_len > MAX_ADJST_OFFSET || hdr_len == 0)
+ return -1;
+
+ /* Added here to handle clang complain about negative value */
+ hdr_len = hdr_len & 0xff;
+
+ if (hdr_len == 0)
+ return -1;
+
+ if (bpf_xdp_load_bytes(ctx, 0, hdr_buff, hdr_len) < 0)
+ return -1;
+
+ if (offset > MAX_ADJST_OFFSET)
+ return -1;
+
+ if (bpf_xdp_adjust_head(ctx, 0 - offset) < 0)
+ return -1;
+
+ if (bpf_xdp_store_bytes(ctx, 0, hdr_buff, hdr_len) < 0)
+ return -1;
+
+ if (bpf_xdp_store_bytes(ctx, hdr_len, data_buff, offset) < 0)
+ return -1;
+
+ return 0;
+}
+
+static int xdp_head_adjst(struct xdp_md *ctx, __u16 port)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct udphdr *udph_ptr = NULL;
+ __u32 key, size, hdr_len;
+ __s32 *val;
+ int res;
+
+ /* Filter packets based on UDP port */
+ udph_ptr = filter_udphdr(ctx, port);
+ if (!udph_ptr)
+ return XDP_PASS;
+
+ hdr_len = (void *)udph_ptr - data + sizeof(struct udphdr);
+
+ key = XDP_ADJST_OFFSET;
+ val = bpf_map_lookup_elem(&map_xdp_setup, &key);
+ if (!val)
+ return XDP_PASS;
+
+ switch (*val) {
+ case -16:
+ case 16:
+ size = 16;
+ break;
+ case -32:
+ case 32:
+ size = 32;
+ break;
+ case -64:
+ case 64:
+ size = 64;
+ break;
+ case -128:
+ case 128:
+ size = 128;
+ break;
+ case -256:
+ case 256:
+ size = 256;
+ break;
+ default:
+ bpf_printk("Invalid adjustment offset: %d\n", *val);
+ goto abort;
+ }
+
+ if (*val < 0)
+ res = xdp_adjst_head_grow_data(ctx, hdr_len, size);
+ else
+ res = xdp_adjst_head_shrnk_data(ctx, hdr_len, size);
+
+ if (res)
+ goto abort;
+
+ record_stats(ctx, STATS_PASS);
+ return XDP_PASS;
+
+abort:
+ record_stats(ctx, STATS_ABORT);
+ return XDP_ABORTED;
+}
+
+static int xdp_prog_common(struct xdp_md *ctx)
+{
+ __u32 key, *port;
+ __s32 *mode;
+
+ key = XDP_MODE;
+ mode = bpf_map_lookup_elem(&map_xdp_setup, &key);
+ if (!mode)
+ return XDP_PASS;
+
+ key = XDP_PORT;
+ port = bpf_map_lookup_elem(&map_xdp_setup, &key);
+ if (!port)
+ return XDP_PASS;
+
+ switch (*mode) {
+ case XDP_MODE_PASS:
+ return xdp_mode_pass(ctx, (__u16)(*port));
+ case XDP_MODE_DROP:
+ return xdp_mode_drop_handler(ctx, (__u16)(*port));
+ case XDP_MODE_TX:
+ return xdp_mode_tx_handler(ctx, (__u16)(*port));
+ case XDP_MODE_TAIL_ADJST:
+ return xdp_adjst_tail(ctx, (__u16)(*port));
+ case XDP_MODE_HEAD_ADJST:
+ return xdp_head_adjst(ctx, (__u16)(*port));
+ }
+
+ /* Default action is to simple pass */
+ return XDP_PASS;
+}
+
+SEC("xdp")
+int xdp_prog(struct xdp_md *ctx)
+{
+ return xdp_prog_common(ctx);
+}
+
+SEC("xdp.frags")
+int xdp_prog_frags(struct xdp_md *ctx)
+{
+ return xdp_prog_common(ctx);
+}
+
+char _license[] SEC("license") = "GPL";
generated by cgit (git 2.34.1) at 2025-07-31 18:22:39 +0000