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author | Lawrence Brakmo <brakmo@fb.com> | 2017-06-30 20:02:41 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2017-07-01 16:15:13 -0700 |
commit | ae16189efb0fe2bdc5e702bd6221ed6d0ff5babd (patch) | |
tree | 59dfe86ee7237f06ac230eacc7bf5bddf6dbdb77 /samples/bpf/load_sock_ops.c | |
parent | 40304b2a1567fecc321f640ee4239556dd0f3ee0 (diff) | |
download | linux-stable-ae16189efb0fe2bdc5e702bd6221ed6d0ff5babd.tar.gz linux-stable-ae16189efb0fe2bdc5e702bd6221ed6d0ff5babd.tar.bz2 linux-stable-ae16189efb0fe2bdc5e702bd6221ed6d0ff5babd.zip |
bpf: program to load and attach sock_ops BPF progs
The program load_sock_ops can be used to load sock_ops bpf programs and
to attach it to an existing (v2) cgroup. It can also be used to detach
sock_ops programs.
Examples:
load_sock_ops [-l] <cg-path> <prog filename>
Load and attaches a sock_ops program at the specified cgroup.
If "-l" is used, the program will continue to run to output the
BPF log buffer.
If the specified filename does not end in ".o", it appends
"_kern.o" to the name.
load_sock_ops -r <cg-path>
Detaches the currently attached sock_ops program from the
specified cgroup.
Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'samples/bpf/load_sock_ops.c')
-rw-r--r-- | samples/bpf/load_sock_ops.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/samples/bpf/load_sock_ops.c b/samples/bpf/load_sock_ops.c new file mode 100644 index 000000000000..e5da6cf71a3e --- /dev/null +++ b/samples/bpf/load_sock_ops.c @@ -0,0 +1,97 @@ +/* Copyright (c) 2017 Facebook + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <linux/bpf.h> +#include "libbpf.h" +#include "bpf_load.h" +#include <unistd.h> +#include <errno.h> +#include <fcntl.h> +#include <linux/unistd.h> + +static void usage(char *pname) +{ + printf("USAGE:\n %s [-l] <cg-path> <prog filename>\n", pname); + printf("\tLoad and attach a sock_ops program to the specified " + "cgroup\n"); + printf("\tIf \"-l\" is used, the program will continue to run\n"); + printf("\tprinting the BPF log buffer\n"); + printf("\tIf the specified filename does not end in \".o\", it\n"); + printf("\tappends \"_kern.o\" to the name\n"); + printf("\n"); + printf(" %s -r <cg-path>\n", pname); + printf("\tDetaches the currently attached sock_ops program\n"); + printf("\tfrom the specified cgroup\n"); + printf("\n"); + exit(1); +} + +int main(int argc, char **argv) +{ + int logFlag = 0; + int error = 0; + char *cg_path; + char fn[500]; + char *prog; + int cg_fd; + + if (argc < 3) + usage(argv[0]); + + if (!strcmp(argv[1], "-r")) { + cg_path = argv[2]; + cg_fd = open(cg_path, O_DIRECTORY, O_RDONLY); + error = bpf_prog_detach(cg_fd, BPF_CGROUP_SOCK_OPS); + if (error) { + printf("ERROR: bpf_prog_detach: %d (%s)\n", + error, strerror(errno)); + return 2; + } + return 0; + } else if (!strcmp(argv[1], "-h")) { + usage(argv[0]); + } else if (!strcmp(argv[1], "-l")) { + logFlag = 1; + if (argc < 4) + usage(argv[0]); + } + + prog = argv[argc - 1]; + cg_path = argv[argc - 2]; + if (strlen(prog) > 480) { + fprintf(stderr, "ERROR: program name too long (> 480 chars)\n"); + return 3; + } + cg_fd = open(cg_path, O_DIRECTORY, O_RDONLY); + + if (!strcmp(prog + strlen(prog)-2, ".o")) + strcpy(fn, prog); + else + sprintf(fn, "%s_kern.o", prog); + if (logFlag) + printf("loading bpf file:%s\n", fn); + if (load_bpf_file(fn)) { + printf("ERROR: load_bpf_file failed for: %s\n", fn); + printf("%s", bpf_log_buf); + return 4; + } + if (logFlag) + printf("TCP BPF Loaded %s\n", fn); + + error = bpf_prog_attach(prog_fd[0], cg_fd, BPF_CGROUP_SOCK_OPS, 0); + if (error) { + printf("ERROR: bpf_prog_attach: %d (%s)\n", + error, strerror(errno)); + return 5; + } else if (logFlag) { + read_trace_pipe(); + } + + return error; +} |