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Add arguments for sendmmsg and recvmmsg #2027

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Add arguments for sendmmsg and recvmmsg #2027

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a5532b3
feat(modern_bpf): add arguments to recvmmsg and sendmmsg
Molter73 Aug 27, 2024
950d9eb
feat(tests): add tests for recvmmsg and sendmmsg
Molter73 Aug 27, 2024
68c1fd2
feat(bpf): add arguments to recvmmsg and sendmmsg
Molter73 Aug 27, 2024
6a4d60c
feat(kmod): add arguments to recvmmsg and sendmmsg
Molter73 Aug 27, 2024
ba208b1
chore(modern_bpf): add fields to enum bpf_func_id
Molter73 Oct 3, 2024
60f9fd6
cleanup(drivers): move all recvmmsg arguments to the exit event
Molter73 Oct 17, 2024
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230 changes: 230 additions & 0 deletions driver/bpf/fillers.h
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Original file line number Diff line number Diff line change
Expand Up @@ -4253,6 +4253,143 @@ FILLER(sys_recvmsg_x_2, true) {
return res;
}

FILLER(sys_recvmmsg_x, true) {
const struct iovec *iov;
struct mmsghdr mmh;
unsigned long iovcnt;
unsigned long val;
int res;
int fd;

/* Parameter 1: res (type: PT_ERRNO) */
long retval = bpf_syscall_get_retval(data->ctx);

/* If the syscall fails we are not able to collect reliable params
* so we return empty ones.
*/
if(retval < 0) {
res = bpf_push_s64_to_ring(data, retval);
CHECK_RES(res);

/* Parameter 2: fd (type: PT_FD) */
res = bpf_push_empty_param(data);
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like in the other drivers we probably want to push the fd of the syscall here

CHECK_RES(res);

/* Parameter 3: size (type: PT_UINT32) */
res = bpf_push_u32_to_ring(data, 0);
CHECK_RES(res);

/* Parameter 4: data (type: PT_BYTEBUF) */
res = bpf_push_empty_param(data);
CHECK_RES(res);

/* Parameter 5: tuple (type: PT_SOCKTUPLE) */
res = bpf_push_empty_param(data);
CHECK_RES(res);

/* Parameter 6: msg_control (type: PT_BYTEBUF) */
return bpf_push_empty_param(data);
}

fd = bpf_syscall_get_argument(data, 0);

/*
* Retrieve the message header
*/
val = bpf_syscall_get_argument(data, 1);
if(bpf_probe_read_user(&mmh, sizeof(mmh), (void *)val))
return PPM_FAILURE_INVALID_USER_MEMORY;

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can we use the usual comments like /* Parameter 1: res (type: PT_ERRNO) */ just to understand what we are pushing

res = bpf_push_s64_to_ring(data, mmh.msg_len);
CHECK_RES(res);

res = bpf_push_s64_to_ring(data, fd);
CHECK_RES(res);

/*
* data and size
*/
iov = (const struct iovec *)mmh.msg_hdr.msg_iov;
iovcnt = mmh.msg_hdr.msg_iovlen;

res = bpf_parse_readv_writev_bufs(data, iov, iovcnt, mmh.msg_len, PRB_FLAG_PUSH_ALL);
CHECK_RES(res);

bpf_tail_call(data->ctx, &tail_map, PPM_FILLER_sys_recvmmsg_x_2);
bpf_printk("Can't tail call f_sys_recvmsg_x_2 filler\n");
return PPM_FAILURE_BUG;
}

FILLER(sys_recvmmsg_x_2, true) {
struct sockaddr *usrsockaddr;
struct mmsghdr mmh;
unsigned long val;
uint16_t size = 0;
long retval;
int addrlen;
int res;
int fd;

retval = bpf_syscall_get_retval(data->ctx);

/*
* tuple and msg_control
*/

/*
* Retrieve the message header
*/
val = bpf_syscall_get_argument(data, 1);
if(bpf_probe_read_user(&mmh, sizeof(mmh), (void *)val))
return PPM_FAILURE_INVALID_USER_MEMORY;

/*
* Get the address
*/
usrsockaddr = (struct sockaddr *)mmh.msg_hdr.msg_name;
addrlen = mmh.msg_hdr.msg_namelen;

if(usrsockaddr && addrlen != 0) {
/*
* Copy the address
*/
res = bpf_addr_to_kernel(usrsockaddr, addrlen, (struct sockaddr *)data->tmp_scratch);

if(res >= 0) {
fd = bpf_syscall_get_argument(data, 0);

/*
* Convert the fd into socket endpoint information
*/
size = bpf_fd_to_socktuple(data,
fd,
(struct sockaddr *)data->tmp_scratch,
addrlen,
true,
true,
data->tmp_scratch + sizeof(struct sockaddr_storage));
}
}

data->curarg_already_on_frame = true;
res = __bpf_val_to_ring(data, 0, size, PT_SOCKTUPLE, -1, false, KERNEL);
CHECK_RES(res);

if(mmh.msg_hdr.msg_control != NULL) {
res = __bpf_val_to_ring(data,
(unsigned long)mmh.msg_hdr.msg_control,
mmh.msg_hdr.msg_controllen,
PT_BYTEBUF,
-1,
false,
USER);
} else {
res = bpf_push_empty_param(data);
}

return res;
}

FILLER(sys_sendmsg_e, true) {
struct sockaddr *usrsockaddr;
const struct iovec *iov;
Expand Down Expand Up @@ -4346,6 +4483,99 @@ FILLER(sys_sendmsg_x, true) {
return res;
}

FILLER(sys_sendmmsg_x, true) {
struct sockaddr *usrsockaddr;
struct mmsghdr mmh = {0};
struct mmsghdr *mmh_ptr;
unsigned long vlen;
unsigned long val;
uint16_t size = 0;
int addrlen;
int err = 0;
int res;
long retval = bpf_syscall_get_retval(data->ctx);
int fd;

if(retval < 0) {
/* Parameter 1: res (type: PT_ERRNO) */
res = bpf_push_s64_to_ring(data, retval);
CHECK_RES(res);

/* Parameter 2: fd (type: PT_BYTEBUF) */
bpf_push_empty_param(data);
CHECK_RES(res);

/* Parameter 3: size (type: PT_UINT32) */
bpf_push_u32_to_ring(data, 0);
CHECK_RES(res);

/* Parameter 4: data (type: PT_BYTEBUF) */
bpf_push_empty_param(data);
CHECK_RES(res);

/* Parameter 5: tuple (type: PT_SOCKTUPLE) */
return bpf_push_empty_param(data);
}

fd = bpf_syscall_get_argument(data, 0);
mmh_ptr = (struct mmsghdr *)bpf_syscall_get_argument(data, 1);
vlen = bpf_syscall_get_argument(data, 2);

/* Retrieve the message header */
if(bpf_probe_read_user(&mmh, sizeof(mmh), (void *)(mmh_ptr))) {
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so if mmh_ptr we rely on the fact that mmh is zeroed and we won't enter all the following branches, is it true?

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I missed this question the first time I went through the review, sorry.

mmh_ptr is read from the arguments, as such, I assume it will always be pointing to a valid position in memory because the syscall was successful here and we haven't returned control to userspace, so the memory must still be there. If, for whatever reason, the pointer was invalid or it was no longer readable due to a cache miss or such a situation, I would expect bpf_probe_read_user to fail and the event to be dropped altogether, (the if condition will be true).

Am I missing something here?

return PPM_FAILURE_INVALID_USER_MEMORY;
}

/* Parameter 1: res (type: PT_ERRNO) */
res = bpf_push_s64_to_ring(data, mmh.msg_len);
CHECK_RES(res);

/* Parameter 2: fd (type: PT_FD) */
res = bpf_push_s64_to_ring(data, fd);
CHECK_RES(res);

/* Parameter 3: size (type: PT_UINT32) */
/* Parameter 4: data (type: PT_BYTEBUF) */
const struct iovec *iov = (const struct iovec *)mmh.msg_hdr.msg_iov;
unsigned long iovcnt = mmh.msg_hdr.msg_iovlen;

res = bpf_parse_readv_writev_bufs(data,
iov,
iovcnt,
mmh.msg_len,
PRB_FLAG_PUSH_ALL | PRB_FLAG_IS_WRITE);
CHECK_RES(res);

/* Parameter 5: tuple (type: PT_SOCKTUPLE) */
usrsockaddr = (struct sockaddr *)mmh.msg_hdr.msg_name;
addrlen = mmh.msg_hdr.msg_namelen;

if(usrsockaddr && addrlen != 0) {
/*
* Copy the address
*/
err = bpf_addr_to_kernel(usrsockaddr, addrlen, (struct sockaddr *)data->tmp_scratch);

if(err >= 0) {
/*
* Convert the fd into socket endpoint information
*/
size = bpf_fd_to_socktuple(data,
fd,
(struct sockaddr *)data->tmp_scratch,
addrlen,
true,
false,
data->tmp_scratch + sizeof(struct sockaddr_storage));
}

data->curarg_already_on_frame = true;
res = __bpf_val_to_ring(data, 0, size, PT_SOCKTUPLE, -1, false, KERNEL);
}

return res;
}

FILLER(sys_creat_e, true) {
unsigned long val;
unsigned long mode;
Expand Down
21 changes: 19 additions & 2 deletions driver/event_table.c
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Original file line number Diff line number Diff line change
Expand Up @@ -311,7 +311,15 @@ const struct ppm_event_info g_event_info[] = {
2,
{{"res", PT_ERRNO, PF_DEC}, {"data", PT_BYTEBUF, PF_NA}}},
[PPME_SOCKET_SENDMMSG_E] = {"sendmmsg", EC_IO_WRITE | EC_SYSCALL, EF_NONE, 0},
[PPME_SOCKET_SENDMMSG_X] = {"sendmmsg", EC_IO_WRITE | EC_SYSCALL, EF_NONE, 0},
[PPME_SOCKET_SENDMMSG_X] = {"sendmmsg",
EC_IO_WRITE | EC_SYSCALL,
EF_USES_FD | EF_WRITES_TO_FD | EF_MODIFIES_STATE,
5,
{{"res", PT_ERRNO, PF_DEC},
{"fd", PT_FD, PF_DEC},
{"size", PT_UINT32, PF_DEC},
{"data", PT_BYTEBUF, PF_NA},
{"tuple", PT_SOCKTUPLE, PF_NA}}},
[PPME_SOCKET_RECVMSG_E] = {"recvmsg",
EC_IO_READ | EC_SYSCALL,
EF_USES_FD | EF_READS_FROM_FD | EF_MODIFIES_STATE,
Expand All @@ -327,7 +335,16 @@ const struct ppm_event_info g_event_info[] = {
{"tuple", PT_SOCKTUPLE, PF_NA},
{"msgcontrol", PT_BYTEBUF, PF_NA}}},
[PPME_SOCKET_RECVMMSG_E] = {"recvmmsg", EC_IO_READ | EC_SYSCALL, EF_NONE, 0},
[PPME_SOCKET_RECVMMSG_X] = {"recvmmsg", EC_IO_READ | EC_SYSCALL, EF_NONE, 0},
[PPME_SOCKET_RECVMMSG_X] = {"recvmmsg",
EC_IO_READ | EC_SYSCALL,
EF_USES_FD | EF_READS_FROM_FD | EF_MODIFIES_STATE,
6,
{{"res", PT_ERRNO, PF_DEC},
{"fd", PT_FD, PF_DEC},
{"size", PT_UINT32, PF_DEC},
{"data", PT_BYTEBUF, PF_NA},
{"tuple", PT_SOCKTUPLE, PF_NA},
{"msgcontrol", PT_BYTEBUF, PF_NA}}},
[PPME_SOCKET_ACCEPT4_E] = {"accept",
EC_NET | EC_SYSCALL,
EF_CREATES_FD | EF_MODIFIES_STATE | EF_OLD_VERSION,
Expand Down
4 changes: 2 additions & 2 deletions driver/fillers_table.c
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Original file line number Diff line number Diff line change
Expand Up @@ -67,11 +67,11 @@ const struct ppm_event_entry g_ppm_events[PPM_EVENT_MAX] = {
[PPME_SOCKET_SENDMSG_E] = {FILLER_REF(sys_sendmsg_e)},
[PPME_SOCKET_SENDMSG_X] = {FILLER_REF(sys_sendmsg_x)},
[PPME_SOCKET_SENDMMSG_E] = {FILLER_REF(sys_empty)},
[PPME_SOCKET_SENDMMSG_X] = {FILLER_REF(sys_empty)},
[PPME_SOCKET_SENDMMSG_X] = {FILLER_REF(sys_sendmmsg_x)},
[PPME_SOCKET_RECVMSG_E] = {FILLER_REF(sys_recvmsg_e)},
[PPME_SOCKET_RECVMSG_X] = {FILLER_REF(sys_recvmsg_x)},
[PPME_SOCKET_RECVMMSG_E] = {FILLER_REF(sys_empty)},
[PPME_SOCKET_RECVMMSG_X] = {FILLER_REF(sys_empty)},
[PPME_SOCKET_RECVMMSG_X] = {FILLER_REF(sys_recvmmsg_x)},
[PPME_SYSCALL_CREAT_E] = {FILLER_REF(sys_creat_e)},
[PPME_SYSCALL_CREAT_X] = {FILLER_REF(sys_creat_x)},
[PPME_SYSCALL_PIPE_E] = {FILLER_REF(sys_empty)},
Expand Down
33 changes: 32 additions & 1 deletion driver/modern_bpf/definitions/aarch64/vmlinux.h
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Original file line number Diff line number Diff line change
Expand Up @@ -7538,7 +7538,38 @@ enum bpf_func_id {
BPF_FUNC_ktime_get_coarse_ns = 160,
BPF_FUNC_ima_inode_hash = 161,
BPF_FUNC_sock_from_file = 162,
__BPF_FUNC_MAX_ID = 163,
BPF_FUNC_check_mtu = 163,
BPF_FUNC_for_each_map_elem = 164,
BPF_FUNC_snprintf = 165,
BPF_FUNC_sys_bpf = 166,
BPF_FUNC_btf_find_by_name_kind = 167,
BPF_FUNC_sys_close = 168,
BPF_FUNC_timer_init = 169,
BPF_FUNC_timer_set_callback = 170,
BPF_FUNC_timer_start = 171,
BPF_FUNC_timer_cancel = 172,
BPF_FUNC_get_func_ip = 173,
BPF_FUNC_get_attach_cookie = 174,
BPF_FUNC_task_pt_regs = 175,
BPF_FUNC_get_branch_snapshot = 176,
BPF_FUNC_trace_vprintk = 177,
BPF_FUNC_skc_to_unix_sock = 178,
BPF_FUNC_kallsyms_lookup_name = 179,
BPF_FUNC_find_vma = 180,
BPF_FUNC_loop = 181,
BPF_FUNC_strncmp = 182,
BPF_FUNC_get_func_arg = 183,
BPF_FUNC_get_func_ret = 184,
BPF_FUNC_get_func_arg_cnt = 185,
BPF_FUNC_get_retval = 186,
BPF_FUNC_set_retval = 187,
BPF_FUNC_xdp_get_buff_len = 188,
BPF_FUNC_xdp_load_bytes = 189,
BPF_FUNC_xdp_store_bytes = 190,
BPF_FUNC_copy_from_user_task = 191,
BPF_FUNC_skb_set_tstamp = 192,
BPF_FUNC_ima_file_hash = 193,
__BPF_FUNC_MAX_ID = 194,
};

struct bpf_func_info {
Expand Down
2 changes: 0 additions & 2 deletions driver/modern_bpf/definitions/events_dimensions.h
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Original file line number Diff line number Diff line change
Expand Up @@ -206,9 +206,7 @@
HEADER_LEN + sizeof(int64_t) * 2 + sizeof(uint64_t) + sizeof(uint32_t) + PARAM_LEN * 4
#define SPLICE_X_SIZE HEADER_LEN + sizeof(int64_t) + PARAM_LEN
#define RECVMMSG_E_SIZE HEADER_LEN
#define RECVMMSG_X_SIZE HEADER_LEN
#define SENDMMSG_E_SIZE HEADER_LEN
#define SENDMMSG_X_SIZE HEADER_LEN
#define SEMOP_E_SIZE HEADER_LEN + sizeof(int32_t) + PARAM_LEN
#define SEMOP_X_SIZE \
HEADER_LEN + sizeof(int64_t) + sizeof(uint32_t) + sizeof(uint16_t) * 4 + sizeof(int16_t) * 2 + \
Expand Down
33 changes: 32 additions & 1 deletion driver/modern_bpf/definitions/x86_64/vmlinux.h
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Original file line number Diff line number Diff line change
Expand Up @@ -39754,7 +39754,38 @@ enum bpf_func_id {
BPF_FUNC_ktime_get_coarse_ns = 160,
BPF_FUNC_ima_inode_hash = 161,
BPF_FUNC_sock_from_file = 162,
__BPF_FUNC_MAX_ID = 163,
BPF_FUNC_check_mtu = 163,
BPF_FUNC_for_each_map_elem = 164,
BPF_FUNC_snprintf = 165,
BPF_FUNC_sys_bpf = 166,
BPF_FUNC_btf_find_by_name_kind = 167,
BPF_FUNC_sys_close = 168,
BPF_FUNC_timer_init = 169,
BPF_FUNC_timer_set_callback = 170,
BPF_FUNC_timer_start = 171,
BPF_FUNC_timer_cancel = 172,
BPF_FUNC_get_func_ip = 173,
BPF_FUNC_get_attach_cookie = 174,
BPF_FUNC_task_pt_regs = 175,
BPF_FUNC_get_branch_snapshot = 176,
BPF_FUNC_trace_vprintk = 177,
BPF_FUNC_skc_to_unix_sock = 178,
BPF_FUNC_kallsyms_lookup_name = 179,
BPF_FUNC_find_vma = 180,
BPF_FUNC_loop = 181,
BPF_FUNC_strncmp = 182,
BPF_FUNC_get_func_arg = 183,
BPF_FUNC_get_func_ret = 184,
BPF_FUNC_get_func_arg_cnt = 185,
BPF_FUNC_get_retval = 186,
BPF_FUNC_set_retval = 187,
BPF_FUNC_xdp_get_buff_len = 188,
BPF_FUNC_xdp_load_bytes = 189,
BPF_FUNC_xdp_store_bytes = 190,
BPF_FUNC_copy_from_user_task = 191,
BPF_FUNC_skb_set_tstamp = 192,
BPF_FUNC_ima_file_hash = 193,
__BPF_FUNC_MAX_ID = 194,
};

enum {
Expand Down
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