BPF适配不同的编译环境

bpf/bpf_obj.cpp

@@ -0,0 +1,125 @@
+#include <errno.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <linux/if_tun.h>
+
+#ifdef SUPPORT_BPF
+#include "bpf_config_user.h"
+
+#define MIN(a, b) ((a) > (b) ? (b) : (a))
+
+struct bpf_obj_ctx
+{
+    char obj_file[1024];
+    struct bpf_config config;
+
+    int prog_fd;
+    struct bpf_object *prog_obj;
+};
+
+void bpf_obj_unload(struct bpf_obj_ctx *ctx)
+{
+    if (ctx)
+    {
+        if (ctx->prog_fd > 0)
+        {
+            close(ctx->prog_fd);
+        }
+
+        if (ctx->prog_obj)
+        {
+            bpf_object__close(ctx->prog_obj);
+            ctx->prog_obj = NULL;
+        }
+
+        free(ctx);
+        ctx = NULL;
+    }
+}
+
+/*
+ * queue_num : same as worker thread number
+ * hash_mode : 2: hash with src/dst addr
+ *             4: hash with src/dst addr and src/dst port
+ * debug_log : 0 for disable(only use for debug, printf bpf debug log(cat /sys/kernel/debug/tracing/trace_pipe)
+ */
+struct bpf_obj_ctx *bpf_obj_load(const char *obj_file, uint32_t queue_num, uint32_t hash_mode, uint32_t debug_log)
+{
+    struct bpf_obj_ctx *ctx = (struct bpf_obj_ctx *)calloc(1, sizeof(struct bpf_obj_ctx));
+
+    strncpy(ctx->obj_file, obj_file, MIN(strlen(obj_file), sizeof(ctx->obj_file)));
+    bpf_config_set_queue_num(&ctx->config, queue_num);
+    bpf_config_set_hash_mode(&ctx->config, hash_mode);
+    bpf_config_set_debug_log(&ctx->config, debug_log);
+
+    if (bpf_prog_load(ctx->obj_file, BPF_PROG_TYPE_SOCKET_FILTER, &ctx->prog_obj, &ctx->prog_fd) < 0)
+    {
+        printf("ERROR: Unable to load bpf object %s, %s.\n", ctx->obj_file, strerror(errno));
+        goto error;
+    }
+
+    if (bpf_config_update_map(&ctx->config, ctx->prog_obj) == -1)
+    {
+        goto error;
+    }
+
+    return ctx;
+
+error:
+    bpf_obj_unload(ctx);
+
+    return NULL;
+}
+
+/*
+ * return  0 : success
+ * return -1 : error
+ */
+int bpf_obj_attach(struct bpf_obj_ctx *ctx, int fd)
+{
+    if (ctx && ctx->prog_fd > 0)
+    {
+        if (ioctl(fd, TUNSETSTEERINGEBPF, (void *)&ctx->prog_fd) == -1)
+        {
+            printf("ERROR: Unable to set bpf on sockfd %d, %s.\n", fd, strerror(errno));
+            return -1;
+        }
+        else
+        {
+            printf("Set TUNSETSTEERINGEBPF on fd: %d\n", fd);
+            return 0;
+        }
+    }
+    else
+    {
+        return -1;
+    }
+}
+#else
+
+struct bpf_obj_ctx
+{
+};
+
+#include <sys/types.h>
+
+void bpf_obj_unload(struct bpf_obj_ctx *ctx)
+{
+    printf("ERROR: BPF feature not support on current system\n");
+}
+
+struct bpf_obj_ctx *bpf_obj_load(const char *obj_file, uint32_t queue_num, uint32_t hash_mode, uint32_t debug_log)
+{
+    printf("ERROR: BPF feature not support on current system\n");
+    return NULL;
+}
+
+int bpf_obj_attach(struct bpf_obj_ctx *ctx, int fd)
+{
+    printf("ERROR: BPF feature not support on current system\n");
+    return -1;
+}
+#endif