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/*
* SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
*/
#ifdef USE_BPF
#include <linux/bpf.h>
#include <linux/filter.h>
#include "arch.h"
#include "bpf.h"
#include "net.h"
#include "random.h"
#include "sanitise.h"
static unsigned long bpf_prog_types[] = {
BPF_PROG_TYPE_UNSPEC,
BPF_PROG_TYPE_SOCKET_FILTER,
BPF_PROG_TYPE_KPROBE,
BPF_PROG_TYPE_SCHED_CLS,
BPF_PROG_TYPE_SCHED_ACT,
BPF_PROG_TYPE_TRACEPOINT,
BPF_PROG_TYPE_XDP,
BPF_PROG_TYPE_PERF_EVENT,
};
static const char license[] = "GPLv2";
static void bpf_prog_load(union bpf_attr *attr)
{
unsigned long *insns = NULL, len = 0;
attr->prog_type = RAND_ARRAY(bpf_prog_types);
switch (attr->prog_type) {
case BPF_PROG_TYPE_SOCKET_FILTER:
bpf_gen_filter(&insns, &len);
break;
default:
// this will go away when all the other cases are enumerated
insns = zmalloc(page_size);
generate_rand_bytes((unsigned char *)insns, len);
break;
}
attr->insn_cnt = len;
attr->insns = (u64) insns;
attr->license = (u64) license;
attr->log_level = 0;
attr->log_size = rnd() % page_size;
attr->log_buf = (u64) get_writable_address(page_size);
attr->kern_version = rnd(); // TODO: stick uname in here.
}
#ifndef BPF_OBJ_PIN
#define BPF_OBJ_PIN 6
#define BPF_OBJ_GET 7
#endif
static void sanitise_bpf(struct syscallrecord *rec)
{
union bpf_attr *attr;
unsigned long bpf_map_types[] = {
BPF_MAP_TYPE_HASH, BPF_MAP_TYPE_ARRAY, BPF_MAP_TYPE_PROG_ARRAY, BPF_MAP_TYPE_PERF_EVENT_ARRAY,
BPF_MAP_TYPE_PERCPU_HASH, BPF_MAP_TYPE_PERCPU_ARRAY, BPF_MAP_TYPE_STACK_TRACE, BPF_MAP_TYPE_CGROUP_ARRAY,
BPF_MAP_TYPE_LRU_HASH, BPF_MAP_TYPE_LRU_HASH, BPF_MAP_TYPE_LRU_PERCPU_HASH, BPF_MAP_TYPE_LPM_TRIE,
};
attr = zmalloc(sizeof(union bpf_attr));
rec->a2 = (unsigned long) attr;
switch (rec->a1) {
case BPF_MAP_CREATE:
attr->map_type = RAND_ARRAY(bpf_map_types);
attr->key_size = rnd() % 1024;
attr->value_size = rnd() % (1024 * 64);
attr->max_entries = rnd() % 1024;
attr->flags = RAND_RANGE(0, 4);
rec->a3 = 20;
break;
case BPF_MAP_LOOKUP_ELEM:
attr->map_fd = get_rand_bpf_fd();
attr->key = RAND_RANGE(0, 10);
attr->value = rnd();
rec->a3 = 32;
break;
case BPF_MAP_UPDATE_ELEM:
attr->map_fd = get_rand_bpf_fd();
attr->key = RAND_RANGE(0, 10);
attr->value = rnd();
attr->next_key = rnd();
attr->flags = RAND_RANGE(0, 4);
rec->a3 = 32;
break;
case BPF_MAP_DELETE_ELEM:
attr->map_fd = get_rand_bpf_fd();
attr->key = RAND_RANGE(0, 10);
rec->a3 = 32;
break;
case BPF_MAP_GET_NEXT_KEY:
attr->map_fd = get_rand_bpf_fd();
attr->key = RAND_RANGE(0, 10);
attr->value = rnd();
rec->a3 = 32;
break;
case BPF_OBJ_PIN:
case BPF_OBJ_GET:
attr->map_fd = get_rand_bpf_fd();
rec->a3 = 32;
break;
case BPF_PROG_LOAD:
bpf_prog_load(attr);
rec->a3 = 48;
break;
default:
break;
}
}
static void post_bpf(struct syscallrecord *rec)
{
union bpf_attr *attr = (union bpf_attr *) rec->a2;
switch (rec->a1) {
case BPF_MAP_CREATE:
//TODO: add fd to local object cache
break;
case BPF_PROG_LOAD:
//TODO: add fd to local object cache
if (attr->prog_type == BPF_PROG_TYPE_SOCKET_FILTER) {
void *ptr = (void *) attr->insns;
free(ptr);
}
break;
default:
break;
}
freeptr(&rec->a2);
}
static unsigned long bpf_cmds[] = {
BPF_MAP_CREATE, BPF_MAP_LOOKUP_ELEM, BPF_MAP_UPDATE_ELEM, BPF_MAP_DELETE_ELEM,
BPF_MAP_GET_NEXT_KEY, BPF_PROG_LOAD, BPF_OBJ_PIN, BPF_OBJ_GET,
};
struct syscallentry syscall_bpf = {
.name = "bpf",
.num_args = 3,
.arg1name = "cmd",
.arg1type = ARG_OP,
.arg1list = ARGLIST(bpf_cmds),
.arg2name = "uattr",
.arg3name = "size",
.sanitise = sanitise_bpf,
.post = post_bpf,
};
#endif
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