d4fffba4d0
Currently old compile rule (CLANG-bpf) doesn't contains VMLINUX_H define
flag which is essential for the bpf program that includes "vmlinux.h".
Also old compile rule doesn't directly specify the compile target as bpf,
instead it uses bunch of extra options with clang followed by long chain
of commands. (e.g. clang | opt | llvm-dis | llc)
In Makefile, there is already new compile rule which is more simple and
neat. And it also has -D__VMLINUX_H__ option. By just changing the _kern
suffix to .bpf will inherit the benefit of the new CLANG-BPF compile
target.
Also, this commit adds dummy gnu/stub.h to the samples/bpf directory.
As commit 1c2dd16add7e ("selftests/bpf: get rid of -D__x86_64__") noted,
compiling with 'clang -target bpf' will raise an error with stubs.h
unless workaround (-D__x86_64) is used. This commit solves this problem
by adding dummy stub.h to make /usr/include/features.h to follow the
expected path as the same way selftests/bpf dealt with.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-4-danieltimlee@gmail.com
109 lines
3.3 KiB
C
109 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <stdio.h>
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#include <assert.h>
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#include <unistd.h>
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#include <bpf/bpf.h>
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#include <bpf/libbpf.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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int main(int ac, char **argv)
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{
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struct sockaddr_in *serv_addr_in, *mapped_addr_in, *tmp_addr_in;
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struct sockaddr serv_addr, mapped_addr, tmp_addr;
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int serverfd, serverconnfd, clientfd, map_fd;
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struct bpf_link *link = NULL;
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struct bpf_program *prog;
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struct bpf_object *obj;
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socklen_t sockaddr_len;
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char filename[256];
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char *ip;
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serv_addr_in = (struct sockaddr_in *)&serv_addr;
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mapped_addr_in = (struct sockaddr_in *)&mapped_addr;
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tmp_addr_in = (struct sockaddr_in *)&tmp_addr;
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snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
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obj = bpf_object__open_file(filename, NULL);
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if (libbpf_get_error(obj)) {
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fprintf(stderr, "ERROR: opening BPF object file failed\n");
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return 0;
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}
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prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
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if (libbpf_get_error(prog)) {
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fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
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goto cleanup;
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}
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/* load BPF program */
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if (bpf_object__load(obj)) {
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fprintf(stderr, "ERROR: loading BPF object file failed\n");
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goto cleanup;
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}
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map_fd = bpf_object__find_map_fd_by_name(obj, "dnat_map");
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if (map_fd < 0) {
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fprintf(stderr, "ERROR: finding a map in obj file failed\n");
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goto cleanup;
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}
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link = bpf_program__attach(prog);
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if (libbpf_get_error(link)) {
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fprintf(stderr, "ERROR: bpf_program__attach failed\n");
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link = NULL;
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goto cleanup;
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}
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assert((serverfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
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assert((clientfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
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/* Bind server to ephemeral port on lo */
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memset(&serv_addr, 0, sizeof(serv_addr));
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serv_addr_in->sin_family = AF_INET;
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serv_addr_in->sin_port = 0;
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serv_addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
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assert(bind(serverfd, &serv_addr, sizeof(serv_addr)) == 0);
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sockaddr_len = sizeof(serv_addr);
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assert(getsockname(serverfd, &serv_addr, &sockaddr_len) == 0);
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ip = inet_ntoa(serv_addr_in->sin_addr);
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printf("Server bound to: %s:%d\n", ip, ntohs(serv_addr_in->sin_port));
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memset(&mapped_addr, 0, sizeof(mapped_addr));
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mapped_addr_in->sin_family = AF_INET;
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mapped_addr_in->sin_port = htons(5555);
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mapped_addr_in->sin_addr.s_addr = inet_addr("255.255.255.255");
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assert(!bpf_map_update_elem(map_fd, &mapped_addr, &serv_addr, BPF_ANY));
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assert(listen(serverfd, 5) == 0);
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ip = inet_ntoa(mapped_addr_in->sin_addr);
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printf("Client connecting to: %s:%d\n",
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ip, ntohs(mapped_addr_in->sin_port));
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assert(connect(clientfd, &mapped_addr, sizeof(mapped_addr)) == 0);
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sockaddr_len = sizeof(tmp_addr);
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ip = inet_ntoa(tmp_addr_in->sin_addr);
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assert((serverconnfd = accept(serverfd, &tmp_addr, &sockaddr_len)) > 0);
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printf("Server received connection from: %s:%d\n",
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ip, ntohs(tmp_addr_in->sin_port));
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sockaddr_len = sizeof(tmp_addr);
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assert(getpeername(clientfd, &tmp_addr, &sockaddr_len) == 0);
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ip = inet_ntoa(tmp_addr_in->sin_addr);
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printf("Client's peer address: %s:%d\n",
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ip, ntohs(tmp_addr_in->sin_port));
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/* Is the server's getsockname = the socket getpeername */
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assert(memcmp(&serv_addr, &tmp_addr, sizeof(struct sockaddr_in)) == 0);
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cleanup:
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bpf_link__destroy(link);
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bpf_object__close(obj);
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return 0;
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}
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