| /* |
| * f_bpf.c BPF-based Classifier |
| * |
| * This program is free software; you can distribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Authors: Daniel Borkmann <dborkman@redhat.com> |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <syslog.h> |
| #include <fcntl.h> |
| #include <libgen.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| #include <string.h> |
| #include <stdbool.h> |
| #include <errno.h> |
| #include <limits.h> |
| #include <linux/filter.h> |
| #include <linux/if.h> |
| |
| #include "utils.h" |
| #include "tc_util.h" |
| #include "tc_bpf.h" |
| |
| static const enum bpf_prog_type bpf_type = BPF_PROG_TYPE_SCHED_CLS; |
| |
| static void explain(void) |
| { |
| fprintf(stderr, "Usage: ... bpf ...\n"); |
| fprintf(stderr, "\n"); |
| fprintf(stderr, "BPF use case:\n"); |
| fprintf(stderr, " bytecode BPF_BYTECODE\n"); |
| fprintf(stderr, " bytecode-file FILE\n"); |
| fprintf(stderr, "\n"); |
| fprintf(stderr, "eBPF use case:\n"); |
| fprintf(stderr, " object-file FILE [ section CLS_NAME ] [ export UDS_FILE ]"); |
| fprintf(stderr, " [ verbose ] [ direct-action ]\n"); |
| fprintf(stderr, "\n"); |
| fprintf(stderr, "Common remaining options:\n"); |
| fprintf(stderr, " [ action ACTION_SPEC ]\n"); |
| fprintf(stderr, " [ classid CLASSID ]\n"); |
| fprintf(stderr, "\n"); |
| fprintf(stderr, "Where BPF_BYTECODE := \'s,c t f k,c t f k,c t f k,...\'\n"); |
| fprintf(stderr, "c,t,f,k and s are decimals; s denotes number of 4-tuples\n"); |
| fprintf(stderr, "\n"); |
| fprintf(stderr, "Where FILE points to a file containing the BPF_BYTECODE string,\n"); |
| fprintf(stderr, "an ELF file containing eBPF map definitions and bytecode.\n"); |
| fprintf(stderr, "\n"); |
| fprintf(stderr, "Where CLS_NAME refers to the section name containing the\n"); |
| fprintf(stderr, "classifier (default \'%s\').\n", bpf_default_section(bpf_type)); |
| fprintf(stderr, "\n"); |
| fprintf(stderr, "Where UDS_FILE points to a unix domain socket file in order\n"); |
| fprintf(stderr, "to hand off control of all created eBPF maps to an agent.\n"); |
| fprintf(stderr, "\n"); |
| fprintf(stderr, "ACTION_SPEC := ... look at individual actions\n"); |
| fprintf(stderr, "NOTE: CLASSID is parsed as hexadecimal input.\n"); |
| } |
| |
| static int bpf_parse_opt(struct filter_util *qu, char *handle, |
| int argc, char **argv, struct nlmsghdr *n) |
| { |
| struct tcmsg *t = NLMSG_DATA(n); |
| const char *bpf_uds_name = NULL; |
| const char *bpf_sec_name = NULL; |
| unsigned int bpf_flags = 0; |
| char *bpf_obj = NULL; |
| struct rtattr *tail; |
| bool seen_run = false; |
| long h = 0; |
| int ret = 0; |
| |
| if (argc == 0) |
| return 0; |
| |
| if (handle) { |
| h = strtol(handle, NULL, 0); |
| if (h == LONG_MIN || h == LONG_MAX) { |
| fprintf(stderr, "Illegal handle \"%s\", must be " |
| "numeric.\n", handle); |
| return -1; |
| } |
| } |
| |
| t->tcm_handle = h; |
| |
| tail = (struct rtattr *)(((void *)n) + NLMSG_ALIGN(n->nlmsg_len)); |
| addattr_l(n, MAX_MSG, TCA_OPTIONS, NULL, 0); |
| |
| while (argc > 0) { |
| if (matches(*argv, "run") == 0) { |
| struct sock_filter bpf_ops[BPF_MAXINSNS]; |
| bool from_file, ebpf, bpf_verbose; |
| int ret; |
| |
| NEXT_ARG(); |
| opt_bpf: |
| bpf_sec_name = bpf_default_section(bpf_type); |
| bpf_verbose = false; |
| ebpf = false; |
| seen_run = true; |
| |
| if (strcmp(*argv, "bytecode-file") == 0 || |
| strcmp(*argv, "bcf") == 0) { |
| from_file = true; |
| } else if (strcmp(*argv, "bytecode") == 0 || |
| strcmp(*argv, "bc") == 0) { |
| from_file = false; |
| } else if (strcmp(*argv, "object-file") == 0 || |
| strcmp(*argv, "obj") == 0) { |
| ebpf = true; |
| } else { |
| fprintf(stderr, "What is \"%s\"?\n", *argv); |
| explain(); |
| return -1; |
| } |
| |
| NEXT_ARG(); |
| if (ebpf) { |
| bpf_uds_name = getenv(BPF_ENV_UDS); |
| bpf_obj = *argv; |
| |
| NEXT_ARG_FWD(); |
| |
| if (argc > 0 && |
| (strcmp(*argv, "section") == 0 || |
| strcmp(*argv, "sec") == 0)) { |
| NEXT_ARG(); |
| bpf_sec_name = *argv; |
| NEXT_ARG_FWD(); |
| } |
| if (argc > 0 && !bpf_uds_name && |
| (strcmp(*argv, "export") == 0 || |
| strcmp(*argv, "exp") == 0)) { |
| NEXT_ARG(); |
| bpf_uds_name = *argv; |
| NEXT_ARG_FWD(); |
| } |
| if (argc > 0 && |
| (strcmp(*argv, "verbose") == 0 || |
| strcmp(*argv, "verb") == 0)) { |
| bpf_verbose = true; |
| NEXT_ARG_FWD(); |
| } |
| |
| PREV_ARG(); |
| } |
| |
| ret = ebpf ? bpf_open_object(bpf_obj, bpf_type, bpf_sec_name, |
| bpf_verbose) : |
| bpf_parse_ops(argc, argv, bpf_ops, from_file); |
| if (ret < 0) { |
| fprintf(stderr, "%s\n", ebpf ? |
| "Could not load object" : |
| "Illegal \"bytecode\""); |
| return -1; |
| } |
| |
| if (ebpf) { |
| char bpf_name[256]; |
| |
| bpf_obj = basename(bpf_obj); |
| |
| snprintf(bpf_name, sizeof(bpf_name), "%s:[%s]", |
| bpf_obj, bpf_sec_name); |
| |
| addattr32(n, MAX_MSG, TCA_BPF_FD, ret); |
| addattrstrz(n, MAX_MSG, TCA_BPF_NAME, bpf_name); |
| } else { |
| addattr16(n, MAX_MSG, TCA_BPF_OPS_LEN, ret); |
| addattr_l(n, MAX_MSG, TCA_BPF_OPS, &bpf_ops, |
| ret * sizeof(struct sock_filter)); |
| } |
| } else if (matches(*argv, "classid") == 0 || |
| strcmp(*argv, "flowid") == 0) { |
| unsigned int handle; |
| |
| NEXT_ARG(); |
| if (get_tc_classid(&handle, *argv)) { |
| fprintf(stderr, "Illegal \"classid\"\n"); |
| return -1; |
| } |
| addattr32(n, MAX_MSG, TCA_BPF_CLASSID, handle); |
| } else if (matches(*argv, "direct-action") == 0 || |
| matches(*argv, "da") == 0) { |
| bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT; |
| } else if (matches(*argv, "action") == 0) { |
| NEXT_ARG(); |
| if (parse_action(&argc, &argv, TCA_BPF_ACT, n)) { |
| fprintf(stderr, "Illegal \"action\"\n"); |
| return -1; |
| } |
| continue; |
| } else if (matches(*argv, "police") == 0) { |
| NEXT_ARG(); |
| if (parse_police(&argc, &argv, TCA_BPF_POLICE, n)) { |
| fprintf(stderr, "Illegal \"police\"\n"); |
| return -1; |
| } |
| continue; |
| } else if (strcmp(*argv, "help") == 0) { |
| explain(); |
| return -1; |
| } else { |
| if (!seen_run) |
| goto opt_bpf; |
| |
| fprintf(stderr, "What is \"%s\"?\n", *argv); |
| explain(); |
| return -1; |
| } |
| |
| NEXT_ARG_FWD(); |
| } |
| |
| if (bpf_obj && bpf_flags) |
| addattr32(n, MAX_MSG, TCA_BPF_FLAGS, bpf_flags); |
| |
| tail->rta_len = (((void *)n) + n->nlmsg_len) - (void *)tail; |
| |
| if (bpf_uds_name) |
| ret = bpf_send_map_fds(bpf_uds_name, bpf_obj); |
| |
| return ret; |
| } |
| |
| static int bpf_print_opt(struct filter_util *qu, FILE *f, |
| struct rtattr *opt, __u32 handle) |
| { |
| struct rtattr *tb[TCA_BPF_MAX + 1]; |
| |
| if (opt == NULL) |
| return 0; |
| |
| parse_rtattr_nested(tb, TCA_BPF_MAX, opt); |
| |
| if (handle) |
| fprintf(f, "handle 0x%x ", handle); |
| |
| if (tb[TCA_BPF_CLASSID]) { |
| SPRINT_BUF(b1); |
| fprintf(f, "flowid %s ", |
| sprint_tc_classid(rta_getattr_u32(tb[TCA_BPF_CLASSID]), b1)); |
| } |
| |
| if (tb[TCA_BPF_NAME]) |
| fprintf(f, "%s ", rta_getattr_str(tb[TCA_BPF_NAME])); |
| else if (tb[TCA_BPF_FD]) |
| fprintf(f, "pfd %u ", rta_getattr_u32(tb[TCA_BPF_FD])); |
| |
| if (tb[TCA_BPF_FLAGS]) { |
| unsigned int flags = rta_getattr_u32(tb[TCA_BPF_FLAGS]); |
| |
| if (flags & TCA_BPF_FLAG_ACT_DIRECT) |
| fprintf(f, "direct-action "); |
| } |
| |
| if (tb[TCA_BPF_OPS] && tb[TCA_BPF_OPS_LEN]) { |
| bpf_print_ops(f, tb[TCA_BPF_OPS], |
| rta_getattr_u16(tb[TCA_BPF_OPS_LEN])); |
| fprintf(f, "\n"); |
| } |
| |
| if (tb[TCA_BPF_POLICE]) { |
| fprintf(f, "\n"); |
| tc_print_police(f, tb[TCA_BPF_POLICE]); |
| } |
| |
| if (tb[TCA_BPF_ACT]) { |
| tc_print_action(f, tb[TCA_BPF_ACT]); |
| } |
| |
| return 0; |
| } |
| |
| struct filter_util bpf_filter_util = { |
| .id = "bpf", |
| .parse_fopt = bpf_parse_opt, |
| .print_fopt = bpf_print_opt, |
| }; |