From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 samples/bpf/libbpf.c | 135 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 135 insertions(+)
 create mode 100644 samples/bpf/libbpf.c

(limited to 'samples/bpf/libbpf.c')

diff --git a/samples/bpf/libbpf.c b/samples/bpf/libbpf.c
new file mode 100644
index 000000000..7e1efa7e2
--- /dev/null
+++ b/samples/bpf/libbpf.c
@@ -0,0 +1,135 @@
+/* eBPF mini library */
+#include <stdlib.h>
+#include <stdio.h>
+#include <linux/unistd.h>
+#include <unistd.h>
+#include <string.h>
+#include <linux/netlink.h>
+#include <linux/bpf.h>
+#include <errno.h>
+#include <net/ethernet.h>
+#include <net/if.h>
+#include <linux/if_packet.h>
+#include <arpa/inet.h>
+#include "libbpf.h"
+
+static __u64 ptr_to_u64(void *ptr)
+{
+	return (__u64) (unsigned long) ptr;
+}
+
+int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
+		   int max_entries)
+{
+	union bpf_attr attr = {
+		.map_type = map_type,
+		.key_size = key_size,
+		.value_size = value_size,
+		.max_entries = max_entries
+	};
+
+	return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
+}
+
+int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags)
+{
+	union bpf_attr attr = {
+		.map_fd = fd,
+		.key = ptr_to_u64(key),
+		.value = ptr_to_u64(value),
+		.flags = flags,
+	};
+
+	return syscall(__NR_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
+}
+
+int bpf_lookup_elem(int fd, void *key, void *value)
+{
+	union bpf_attr attr = {
+		.map_fd = fd,
+		.key = ptr_to_u64(key),
+		.value = ptr_to_u64(value),
+	};
+
+	return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
+}
+
+int bpf_delete_elem(int fd, void *key)
+{
+	union bpf_attr attr = {
+		.map_fd = fd,
+		.key = ptr_to_u64(key),
+	};
+
+	return syscall(__NR_bpf, BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
+}
+
+int bpf_get_next_key(int fd, void *key, void *next_key)
+{
+	union bpf_attr attr = {
+		.map_fd = fd,
+		.key = ptr_to_u64(key),
+		.next_key = ptr_to_u64(next_key),
+	};
+
+	return syscall(__NR_bpf, BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
+}
+
+#define ROUND_UP(x, n) (((x) + (n) - 1u) & ~((n) - 1u))
+
+char bpf_log_buf[LOG_BUF_SIZE];
+
+int bpf_prog_load(enum bpf_prog_type prog_type,
+		  const struct bpf_insn *insns, int prog_len,
+		  const char *license, int kern_version)
+{
+	union bpf_attr attr = {
+		.prog_type = prog_type,
+		.insns = ptr_to_u64((void *) insns),
+		.insn_cnt = prog_len / sizeof(struct bpf_insn),
+		.license = ptr_to_u64((void *) license),
+		.log_buf = ptr_to_u64(bpf_log_buf),
+		.log_size = LOG_BUF_SIZE,
+		.log_level = 1,
+	};
+
+	/* assign one field outside of struct init to make sure any
+	 * padding is zero initialized
+	 */
+	attr.kern_version = kern_version;
+
+	bpf_log_buf[0] = 0;
+
+	return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
+}
+
+int open_raw_sock(const char *name)
+{
+	struct sockaddr_ll sll;
+	int sock;
+
+	sock = socket(PF_PACKET, SOCK_RAW | SOCK_NONBLOCK | SOCK_CLOEXEC, htons(ETH_P_ALL));
+	if (sock < 0) {
+		printf("cannot create raw socket\n");
+		return -1;
+	}
+
+	memset(&sll, 0, sizeof(sll));
+	sll.sll_family = AF_PACKET;
+	sll.sll_ifindex = if_nametoindex(name);
+	sll.sll_protocol = htons(ETH_P_ALL);
+	if (bind(sock, (struct sockaddr *)&sll, sizeof(sll)) < 0) {
+		printf("bind to %s: %s\n", name, strerror(errno));
+		close(sock);
+		return -1;
+	}
+
+	return sock;
+}
+
+int perf_event_open(struct perf_event_attr *attr, int pid, int cpu,
+		    int group_fd, unsigned long flags)
+{
+	return syscall(__NR_perf_event_open, attr, pid, cpu,
+		       group_fd, flags);
+}
-- 
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