static void explain(void)
{
fprintf(stderr, "Usage: ... bpf ... [ index INDEX ]\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 ACT_NAME ] [ export UDS_FILE ]");
fprintf(stderr, " [ verbose ]\n");
fprintf(stderr, " object-pinned FILE\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, or a\n");
fprintf(stderr, "pinned eBPF program.\n");
fprintf(stderr, "\n");
fprintf(stderr, "Where ACT_NAME refers to the section name containing the\n");
fprintf(stderr, "action (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, "Where optionally INDEX points to an existing action, or\n");
fprintf(stderr, "explicitly specifies an action index upon creation.\n");
}
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 ACT_NAME ] [ export UDS_FILE ]\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 ACT_NAME refers to the section name containing the\n");
fprintf(stderr, "action (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");
}
static int parse_bpf(struct action_util *a, int *argc_p, char ***argv_p,
int tca_id, struct nlmsghdr *n)
{
char **argv = *argv_p, bpf_name[256];
struct rtattr *tail;
struct tc_act_bpf parm = { 0 };
struct sock_filter bpf_ops[BPF_MAXINSNS];
bool ebpf = false, seen_run = false;
const char *bpf_uds_name = NULL;
const char *bpf_sec_name = NULL;
char *bpf_obj = NULL;
int argc = *argc_p, ret = 0;
__u16 bpf_len = 0;
__u32 bpf_fd = 0;
if (matches(*argv, "bpf") != 0)
return -1;
NEXT_ARG();
while (argc > 0) {
if (matches(*argv, "run") == 0) {
bool from_file;
int ret;
NEXT_ARG();
opt_bpf:
bpf_sec_name = bpf_default_section(bpf_type);
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, "unexpected \"%s\"\n", *argv);
explain();
return -1;
}
NEXT_ARG();
if (ebpf) {
bpf_obj = *argv;
NEXT_ARG();
if (strcmp(*argv, "section") == 0 ||
strcmp(*argv, "sec") == 0) {
NEXT_ARG();
bpf_sec_name = *argv;
NEXT_ARG();
}
if (strcmp(*argv, "export") == 0 ||
strcmp(*argv, "exp") == 0) {
NEXT_ARG();
bpf_uds_name = *argv;
NEXT_ARG();
}
PREV_ARG();
}
ret = ebpf ? bpf_open_object(bpf_obj, bpf_type, bpf_sec_name) :
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) {
bpf_obj = basename(bpf_obj);
snprintf(bpf_name, sizeof(bpf_name), "%s:[%s]",
bpf_obj, bpf_sec_name);
bpf_fd = ret;
} else {
bpf_len = ret;
}
} else if (matches(*argv, "help") == 0) {
usage();
} else {
if (!seen_run)
goto opt_bpf;
break;
}
argc--;
argv++;
}
parm.action = TC_ACT_PIPE;
if (argc) {
if (matches(*argv, "reclassify") == 0) {
parm.action = TC_ACT_RECLASSIFY;
argc--;
argv++;
} else if (matches(*argv, "pipe") == 0) {
parm.action = TC_ACT_PIPE;
argc--;
argv++;
} else if (matches(*argv, "drop") == 0 ||
matches(*argv, "shot") == 0) {
parm.action = TC_ACT_SHOT;
argc--;
argv++;
} else if (matches(*argv, "continue") == 0) {
parm.action = TC_ACT_UNSPEC;
argc--;
argv++;
} else if (matches(*argv, "pass") == 0) {
parm.action = TC_ACT_OK;
argc--;
argv++;
}
}
if (argc) {
if (matches(*argv, "index") == 0) {
NEXT_ARG();
if (get_u32(&parm.index, *argv, 10)) {
fprintf(stderr, "bpf: Illegal \"index\"\n");
return -1;
}
argc--;
argv++;
}
}
if ((!bpf_len && !ebpf) || (!bpf_fd && ebpf)) {
fprintf(stderr, "bpf: Bytecode needs to be passed\n");
explain();
return -1;
}
tail = NLMSG_TAIL(n);
addattr_l(n, MAX_MSG, tca_id, NULL, 0);
addattr_l(n, MAX_MSG, TCA_ACT_BPF_PARMS, &parm, sizeof(parm));
if (ebpf) {
addattr32(n, MAX_MSG, TCA_ACT_BPF_FD, bpf_fd);
addattrstrz(n, MAX_MSG, TCA_ACT_BPF_NAME, bpf_name);
} else {
addattr16(n, MAX_MSG, TCA_ACT_BPF_OPS_LEN, bpf_len);
addattr_l(n, MAX_MSG, TCA_ACT_BPF_OPS, &bpf_ops,
bpf_len * sizeof(struct sock_filter));
}
tail->rta_len = (char *)NLMSG_TAIL(n) - (char *)tail;
*argc_p = argc;
*argv_p = argv;
if (bpf_uds_name)
ret = bpf_send_map_fds(bpf_uds_name, bpf_obj);
return ret;
}