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ppm_events.c
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/*
Copyright (C) 2021 The Falco Authors.
This file is dual licensed under either the MIT or GPL 2. See MIT.txt
or GPL2.txt for full copies of the license.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#ifndef UDIG
#include <linux/compat.h>
#include <linux/kobject.h>
#include <linux/cdev.h>
#include <net/sock.h>
#include <net/af_unix.h>
#include <net/compat.h>
#include <net/ipv6.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/file.h>
#include <linux/fs_struct.h>
#include <linux/uaccess.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <asm/mman.h>
#include <linux/in.h>
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 20)
#include <linux/mount.h>
#include "ppm_syscall.h"
#else
#include <asm/syscall.h>
#endif
#else // UDIG
#define _GNU_SOURCE
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <stdarg.h>
#include <limits.h>
#include <unistd.h>
#include <sys/mman.h>
#include <signal.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/syscall.h>
#include <time.h>
#include <netinet/in.h>
#include <sys/param.h>
#include <sched.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <poll.h>
#include <sys/sem.h>
#include <sys/file.h>
#include <sys/quota.h>
#include <sys/ptrace.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <errno.h>
#include "udig_capture.h"
#include "ppm_ringbuffer.h"
#include "ppm_events_public.h"
#include "ppm_events.h"
#include "ppm.h"
#include "udig_inf.h"
#endif /* UDIG */
#include "ppm_ringbuffer.h"
#include "ppm_events_public.h"
#include "ppm_events.h"
#include "ppm.h"
#include "ppm_flag_helpers.h"
#include "ppm_version.h"
/*
* The kernel patched with grsecurity makes the default access_ok trigger a
* might_sleep(), so if present we use the one defined by them
*/
#ifndef UDIG
#ifdef access_ok_noprefault
#define ppm_access_ok access_ok_noprefault
#else
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)) || (PPM_RHEL_RELEASE_CODE > 0 && PPM_RHEL_RELEASE_CODE >= PPM_RHEL_RELEASE_VERSION(8, 1))
#define ppm_access_ok(type, addr, size) access_ok(addr, size)
#else
#define ppm_access_ok(type, addr, size) access_ok(type, addr, size)
#endif
#endif
extern bool g_tracers_enabled;
static void memory_dump(char *p, size_t size)
{
unsigned int j;
for (j = 0; j < size; j += 8)
pr_info("%*ph\n", 8, &p[j]);
}
#endif // UDIG
static inline bool in_port_range(uint16_t port, uint16_t min, uint16_t max)
{
return port >= min && port <= max;
}
/*
* Globals
*/
u32 g_http_options_intval;
u32 g_http_get_intval;
u32 g_http_head_intval;
u32 g_http_post_intval;
u32 g_http_put_intval;
u32 g_http_delete_intval;
u32 g_http_trace_intval;
u32 g_http_connect_intval;
u32 g_http_resp_intval;
#ifndef UDIG
/*
* What this function does is basically a special memcpy
* so that, if the page fault handler detects the address is invalid,
* won't kill the process but will return a positive number
* Plus, this doesn't sleep.
* The risk is that if the buffer is partially paged out, we get an error.
* Returns the number of bytes NOT read.
*/
unsigned long ppm_copy_from_user(void *to, const void __user *from, unsigned long n)
{
unsigned long res = n;
pagefault_disable();
if (likely(ppm_access_ok(VERIFY_READ, from, n)))
res = __copy_from_user_inatomic(to, from, n);
pagefault_enable();
return res;
}
/*
* On some kernels (e.g. 2.6.39), even with preemption disabled, the strncpy_from_user,
* instead of returning -1 after a page fault, schedules the process, so we drop events
* because of the preemption. This function reads the user buffer in atomic chunks, and
* returns when:
* 1. there's an error (returns `-1`).
* 2. the terminator is found. (the `\0` is computed in the overall length)
* 3. we have read `n` bytes. (in this case, we don't have the `\0` but it's ok we will add it in the caller)
*/
/// TODO: we need to change the return value to `int` and the third param from `unsigned long n` to 'uint32_t n`
long ppm_strncpy_from_user(char *to, const char __user *from, unsigned long n)
{
long string_length = 0;
long res = -1;
unsigned long bytes_to_read = 4;
int j;
pagefault_disable();
while (n) {
/*
* Read bytes_to_read bytes at a time, and look for the terminator. Should be fast
* since the copy_from_user is optimized for the processor
*/
if (n < bytes_to_read)
bytes_to_read = n;
if (!ppm_access_ok(VERIFY_READ, from, bytes_to_read)) {
res = -1;
goto strncpy_end;
}
if (__copy_from_user_inatomic(to, from, bytes_to_read)) {
/*
* Page fault
*/
res = -1;
goto strncpy_end;
}
n -= bytes_to_read;
from += bytes_to_read;
for (j = 0; j < bytes_to_read; ++j) {
++string_length;
/* Check if `*to` is the `\0`. */
if (!*to) {
res = string_length;
goto strncpy_end;
}
++to;
}
}
/* We read all the `n` bytes. */
res = string_length;
strncpy_end:
pagefault_enable();
return res;
}
#endif
int32_t dpi_lookahead_init(void)
{
g_http_options_intval = (*(u32 *)HTTP_OPTIONS_STR);
g_http_get_intval = (*(u32 *)HTTP_GET_STR);
g_http_head_intval = (*(u32 *)HTTP_HEAD_STR);
g_http_post_intval = (*(u32 *)HTTP_POST_STR);
g_http_put_intval = (*(u32 *)HTTP_PUT_STR);
g_http_delete_intval = (*(u32 *)HTTP_DELETE_STR);
g_http_trace_intval = (*(u32 *)HTTP_TRACE_STR);
g_http_connect_intval = (*(u32 *)HTTP_CONNECT_STR);
g_http_resp_intval = (*(u32 *)HTTP_RESP_STR);
return PPM_SUCCESS;
}
#ifndef UDIG
inline int sock_getname(struct socket* sock, struct sockaddr* sock_address, int peer)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0)
/*
* Avoid calling sock->ops->getname(), because in certain kernel versions,
* the getname functions may take a lock, which violates the limitations of
* the RCU lock execution environment which is used by the kernel module.
*
* An example is the usage of `BPF_CGROUP_RUN_SA_PROG_LOCK` since kernel version `5.8.0`
* https://elixir.bootlin.com/linux/v5.8/source/net/ipv4/af_inet.c#L785
*
* For efficiency, only fill in sockaddr fields actually used by the
* kernel module logic; in particular, skip filling in
* - sin_zero
* - sin6_scope_id
* - sin6_flowinfo
*/
struct sock *sk = sock->sk;
switch(sk->sk_family) {
case AF_INET:
{
struct sockaddr_in *sin = (struct sockaddr_in *)sock_address;
struct inet_sock *inet = (struct inet_sock *)sk;
sin->sin_family = AF_INET;
if (peer) {
if (!inet->inet_dport ||
((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT))) {
return -ENOTCONN;
}
sin->sin_port = inet->inet_dport;
sin->sin_addr.s_addr = inet->inet_daddr;
} else {
u32 addr = inet->inet_rcv_saddr;
if (!addr) {
addr = inet->inet_saddr;
}
sin->sin_port = inet->inet_sport;
sin->sin_addr.s_addr = addr;
}
break;
}
case AF_INET6:
{
struct sockaddr_in6 *sin = (struct sockaddr_in6 *)sock_address;
struct inet_sock *inet = (struct inet_sock *)sk;
struct ipv6_pinfo *np = (struct ipv6_pinfo *)inet->pinet6;
sin->sin6_family = AF_INET6;
if (peer) {
if ((!inet->inet_dport) ||
((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT))) {
return -ENOTCONN;
}
sin->sin6_port = inet->inet_dport;
sin->sin6_addr = sk->sk_v6_daddr;
} else {
sin->sin6_addr = sk->sk_v6_rcv_saddr;
if (ipv6_addr_any(&sin->sin6_addr)) {
sin->sin6_addr = np->saddr;
}
sin->sin6_port = inet->inet_sport;
}
break;
}
case AF_UNIX:
{
struct sockaddr_un *sunaddr = (struct sockaddr_un *)sock_address;
struct unix_sock *u;
struct unix_address *u_addr = NULL;
if (peer) {
sk = ((struct unix_sock *)sk)->peer;
if (!sk) {
return -ENOTCONN;
}
}
u = (struct unix_sock *)sk;
u_addr = u->addr;
if (!u_addr) {
sunaddr->sun_family = AF_UNIX;
sunaddr->sun_path[0] = 0;
} else {
unsigned int len = u_addr->len;
if (unlikely(len > sizeof(struct sockaddr_storage))) {
len = sizeof(struct sockaddr_storage);
}
memcpy(sunaddr, u_addr->name, len);
}
break;
}
default:
return -ENOTCONN;
}
return 0;
#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 17, 0)
int ret = sock->ops->getname(sock, sock_address, peer);
if (ret >= 0)
ret = 0;
return ret;
#else
int sockaddr_len;
return sock->ops->getname(sock, sock_address, &sockaddr_len, peer);
#endif
}
/**
* Compute the snaplen for the arguments.
*
* The snaplen is the amount of argument data returned along with the event.
* Normally, the driver performs a dynamic calculation to figure out snaplen
* per-event. However, if this calculation is disabled
* (i.e. args->consumer->do_dynamic_snaplen == false), the snaplen will always
* be args->consumer->snaplen.
*
* If dynamic snaplen is enabled, here's how the calculation works:
*
* 1. If the event is a write to /dev/null, it gets a special snaplen because
* writes to /dev/null is a backdoor method for inserting special events
* into the event stream.
* 2. If the event is NOT a socket operation, return args->consumer->snaplen.
* 3. If the sending port OR destination port falls within the fullcapture port
* range specified by the user, return 16000.
* 4. Protocol detection. A number of applications are detected heuristically
* and given a longer snaplen (2000). These applications are MYSQL, Postgres,
* HTTP, mongodb, and statsd.
* 5. If none of the above apply, return args->consumer->snaplen.
*/
inline u32 compute_snaplen(struct event_filler_arguments *args, char *buf, u32 lookahead_size)
{
u32 res = args->consumer->snaplen;
int err;
struct socket *sock;
sa_family_t family;
struct sockaddr_storage sock_address;
struct sockaddr_storage peer_address;
u16 sport, dport;
u16 min_port = 0, max_port = 0;
u32 dynamic_snaplen = 2000;
if (args->consumer->snaplen > dynamic_snaplen) {
/*
* If the user requested a default snaplen greater than the custom
* snaplen given to certain applications, just use the greater value.
*/
dynamic_snaplen = args->consumer->snaplen;
}
/* Increase snaplen on writes to /dev/null */
if (g_tracers_enabled && args->event_type == PPME_SYSCALL_WRITE_X) {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 14, 0)
struct fd f = fdget(args->fd);
if (f.file && f.file->f_inode) {
if (f.file->f_inode->i_rdev == PPM_NULL_RDEV) {
res = RW_SNAPLEN_EVENT;
fdput(f);
return res;
}
fdput(f);
}
#else
struct file* file = fget(args->fd);
/* Use cached f_inode only on kernel versions that have it
* /~https://github.com/torvalds/linux/commit/dd37978c50bc8b354e5c4633f69387f16572fdac
*/
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 9, 0)
if (file && file->f_inode) {
if (file->f_inode->i_rdev == PPM_NULL_RDEV) {
// Use f_dentry for older kernel versions
#elif LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,20)
if (file && file->f_dentry && file->f_dentry->d_inode) {
if (file->f_dentry->d_inode->i_rdev == PPM_NULL_RDEV) {
#else
if (file && file->f_path.dentry && file->f_path.dentry->d_inode) {
if (file->f_path.dentry->d_inode->i_rdev == PPM_NULL_RDEV) {
#endif
res = RW_SNAPLEN_EVENT;
fput(file);
return res;
}
fput(file);
}
#endif
}
if (!args->consumer->do_dynamic_snaplen)
return res;
sock = sockfd_lookup(args->fd, &err);
if (!sock) {
return res;
}
if (!sock->sk) {
goto done;
}
err = sock_getname(sock, (struct sockaddr *)&sock_address, 0);
if (err != 0) {
goto done;
}
/* Try to get the source and destination port */
if (args->event_type == PPME_SOCKET_SENDTO_X) {
unsigned long syscall_args[6] = {};
unsigned long val;
struct sockaddr __user * usrsockaddr;
/*
* Get the address
*/
if (!args->is_socketcall) {
ppm_syscall_get_arguments(current, args->regs, syscall_args);
val = syscall_args[4];
} else {
val = args->socketcall_args[4];
}
usrsockaddr = (struct sockaddr __user *)val;
if(usrsockaddr == NULL) {
/*
* Suppose is a connected socket, fall back to fd
*/
err = sock_getname(sock, (struct sockaddr *)&peer_address, 1);
} else {
/*
* Get the address len
*/
if (!args->is_socketcall) {
ppm_syscall_get_arguments(current, args->regs, syscall_args);
val = syscall_args[5];
} else {
val = args->socketcall_args[5];
}
if (val != 0) {
/*
* Copy the address
*/
err = addr_to_kernel(usrsockaddr, val, (struct sockaddr *)&peer_address);
} else {
/*
* This case should be very rare, fallback again to sock
*/
err = sock_getname(sock, (struct sockaddr *)&peer_address, 1);
}
}
} else if (args->event_type == PPME_SOCKET_SENDMSG_X) {
unsigned long syscall_args[6] = {};
unsigned long val;
struct sockaddr __user * usrsockaddr;
int addrlen;
#ifdef CONFIG_COMPAT
struct compat_msghdr compat_mh;
#endif
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 19, 0)
struct user_msghdr mh;
#else
struct msghdr mh;
#endif
if (!args->is_socketcall) {
ppm_syscall_get_arguments(current, args->regs, syscall_args);
val = syscall_args[1];
} else {
val = args->socketcall_args[1];
}
#ifdef CONFIG_COMPAT
if (!args->compat) {
#endif
if (unlikely(ppm_copy_from_user(&mh, (const void __user *)val, sizeof(mh)))) {
usrsockaddr = NULL;
addrlen = 0;
} else {
usrsockaddr = (struct sockaddr __user *)mh.msg_name;
addrlen = mh.msg_namelen;
}
#ifdef CONFIG_COMPAT
} else {
if (unlikely(ppm_copy_from_user(&compat_mh, (const void __user *)compat_ptr(val), sizeof(compat_mh)))) {
usrsockaddr = NULL;
addrlen = 0;
} else {
usrsockaddr = (struct sockaddr __user *)compat_ptr(compat_mh.msg_name);
addrlen = compat_mh.msg_namelen;
}
}
#endif
if (usrsockaddr != NULL && addrlen != 0) {
/*
* Copy the address
*/
err = addr_to_kernel(usrsockaddr, addrlen, (struct sockaddr *)&peer_address);
} else {
/*
* Suppose it is a connected socket, fall back to fd
*/
err = sock_getname(sock, (struct sockaddr *)&peer_address, 1);
}
} else {
err = sock_getname(sock, (struct sockaddr *)&peer_address, 1);
}
if (err != 0) {
goto done;
}
/*
* If there's a valid source / dest port, use it to run heuristics
* for determining snaplen.
*/
min_port = args->consumer->fullcapture_port_range_start;
max_port = args->consumer->fullcapture_port_range_end;
family = sock->sk->sk_family;
if (family == AF_INET) {
sport = ntohs(((struct sockaddr_in *) &sock_address)->sin_port);
dport = ntohs(((struct sockaddr_in *) &peer_address)->sin_port);
} else if (family == AF_INET6) {
sport = ntohs(((struct sockaddr_in6 *) &sock_address)->sin6_port);
dport = ntohs(((struct sockaddr_in6 *) &peer_address)->sin6_port);
} else {
sport = 0;
dport = 0;
}
if (max_port > 0 &&
(in_port_range(sport, min_port, max_port) ||
in_port_range(dport, min_port, max_port))) {
/*
* Before checking the well-known ports, see if the user has requested
* an increased snaplen for the port in question.
*/
sockfd_put(sock);
return RW_MAX_FULLCAPTURE_PORT_SNAPLEN;
} else if (sport == PPM_PORT_MYSQL || dport == PPM_PORT_MYSQL) {
if (lookahead_size >= 5) {
if (buf[0] == 3 || buf[1] == 3 || buf[2] == 3 || buf[3] == 3 || buf[4] == 3) {
res = dynamic_snaplen;
goto done;
} else if (buf[2] == 0 && buf[3] == 0) {
res = dynamic_snaplen;
goto done;
}
}
} else if (sport == PPM_PORT_POSTGRES || dport == PPM_PORT_POSTGRES) {
if (lookahead_size >= 2) {
if ((buf[0] == 'Q' && buf[1] == 0) || /* SimpleQuery command */
(buf[0] == 'P' && buf[1] == 0) || /* Prepare statement command */
(buf[0] == 'E' && buf[1] == 0) /* error or execute command */
) {
res = dynamic_snaplen;
goto done;
}
}
if (lookahead_size >= 7 &&
(buf[4] == 0 && buf[5] == 3 && buf[6] == 0)) { /* startup command */
res = dynamic_snaplen;
goto done;
}
} else if ((sport == PPM_PORT_MONGODB || dport == PPM_PORT_MONGODB) ||
(lookahead_size >= 16 &&
(*(int32_t *)(buf+12) == 1 || /* matches header */
*(int32_t *)(buf+12) == 2001 ||
*(int32_t *)(buf+12) == 2002 ||
*(int32_t *)(buf+12) == 2003 ||
*(int32_t *)(buf+12) == 2004 ||
*(int32_t *)(buf+12) == 2005 ||
*(int32_t *)(buf+12) == 2006 ||
*(int32_t *)(buf+12) == 2007)
)
) {
res = dynamic_snaplen;
goto done;
} else if (dport == args->consumer->statsd_port) {
res = dynamic_snaplen;
goto done;
} else {
if (lookahead_size >= 5) {
if (*(u32 *)buf == g_http_get_intval ||
*(u32 *)buf == g_http_post_intval ||
*(u32 *)buf == g_http_put_intval ||
*(u32 *)buf == g_http_delete_intval ||
*(u32 *)buf == g_http_trace_intval ||
*(u32 *)buf == g_http_connect_intval ||
*(u32 *)buf == g_http_options_intval ||
((*(u32 *)buf == g_http_resp_intval) && (buf[4] == '/'))
) {
res = dynamic_snaplen;
goto done;
}
}
}
done:
sockfd_put(sock);
return res;
}
#endif // UDIG
int push_empty_param(struct event_filler_arguments *args)
{
u16 *psize = (u16 *)(args->buffer + args->curarg * sizeof(u16));
if (unlikely(args->curarg >= args->nargs))
{
#ifndef UDIG
pr_err("(%u)val_to_ring: too many arguments for event #%u, type=%u, curarg=%u, nargs=%u tid:%u\n",
smp_processor_id(),
args->nevents,
(u32)args->event_type,
args->curarg,
args->nargs,
current->pid);
memory_dump(args->buffer - sizeof(struct ppm_evt_hdr), 32);
#endif
ASSERT(0);
return PPM_FAILURE_BUG;
}
/* We push 0 in the length array */
*psize = 0;
/* We increment the current argument */
args->curarg++;
return PPM_SUCCESS;
}
/*
* NOTES:
* - val_len is ignored for everything other than PT_BYTEBUF.
* - fromuser is ignored for numeric types
* - dyn_idx is ignored for everything other than PT_DYN
*/
int val_to_ring(struct event_filler_arguments *args, uint64_t val, u32 val_len, bool fromuser, u8 dyn_idx)
{
const struct ppm_param_info *param_info;
int len = -1;
u16 *psize = (u16 *)(args->buffer + args->curarg * sizeof(u16));
u32 max_arg_size = args->arg_data_size;
if (unlikely(args->curarg >= args->nargs)) {
#ifndef UDIG
pr_err("(%u)val_to_ring: too many arguments for event #%u, type=%u, curarg=%u, nargs=%u tid:%u\n",
smp_processor_id(),
args->nevents,
(u32)args->event_type,
args->curarg,
args->nargs,
current->pid);
memory_dump(args->buffer - sizeof(struct ppm_evt_hdr), 32);
#endif
ASSERT(0);
return PPM_FAILURE_BUG;
}
if (unlikely(args->arg_data_size == 0))
return PPM_FAILURE_BUFFER_FULL;
if (max_arg_size > PPM_MAX_ARG_SIZE)
max_arg_size = PPM_MAX_ARG_SIZE;
param_info = &(g_event_info[args->event_type].params[args->curarg]);
if (param_info->type == PT_DYN && param_info->info != NULL) {
const struct ppm_param_info *dyn_params;
if (unlikely(dyn_idx >= param_info->ninfo)) {
ASSERT(0);
return PPM_FAILURE_BUG;
}
#if defined(UDIG)
dyn_params = (const struct ppm_param_info *)patch_pointer((uint8_t*)param_info->info);
#else
dyn_params = (const struct ppm_param_info *)param_info->info;
#endif
param_info = &dyn_params[dyn_idx];
if (likely(max_arg_size >= sizeof(u8))) {
*(u8 *)(args->buffer + args->arg_data_offset) = dyn_idx;
len = sizeof(u8);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
args->arg_data_offset += len;
args->arg_data_size -= len;
max_arg_size -= len;
*psize = (u16)len;
} else {
*psize = 0;
}
switch (param_info->type) {
case PT_CHARBUF:
case PT_FSPATH:
case PT_FSRELPATH:
if(unlikely(val == 0))
{
/* Send an empty param when we have a null pointer `val==0` */
len = 0;
break;
}
if(fromuser)
{
len = ppm_strncpy_from_user(args->buffer + args->arg_data_offset,
(const char __user *)(syscall_arg_t)val, max_arg_size);
if(unlikely(len < 0))
{
len = 0;
break;
}
/* Two possible cases here:
*
* 1. `len < max_arg_size`, the terminator is always there, and `len` takes it into account,
* so we need to do nothing. We just push a `\0` to an empty byte to avoid an if
* case.
*
* 2. `len == max_arg_size`, the terminator is not there but we cannot push an additional
* char for this reason we overwrite the last char and we don't increment `len`.
*/
*(char *)(args->buffer + args->arg_data_offset + max_arg_size - 1) = '\0';
}
else
{
len = (int)strlcpy(args->buffer + args->arg_data_offset,
(const char *)(syscall_arg_t)val,
max_arg_size);
/* WARNING: `strlcpy` returns the length of the string it tries to create
* so `len` could also be greater than `max_arg_size`, but please note that the copied
* charbuf is at max `max_arg_size` (where the last byte is used for the `\0`).
* The copied string is always `\0` terminated but the returned `len` doesn't
* take into consideration the `\0` like `strlen()` function.
*
* Two possible cases here:
*
* 1. `len < max_arg_size`, the terminator is always there, but `len` doesn't take it into account,
* so we need to increment the `len`. Note that if the source string has exactly `max_arg_size`
* characters the returned `len` is `max_arg_size-1` so we need to do `len++` to obtain the copied size.
*
* 2. `len >= max_arg_size`, the source string is greater than `max_arg_size`. `strlcpy` copied
* `max_arg_size - 1` and added the `\0` at the end, so our final copied `len` is `max_arg_size` we have just
* to resize it and we have done.
*/
if(++len >= max_arg_size)
{
len = max_arg_size;
}
}
break;
case PT_BYTEBUF:
if (likely(val != 0 && val_len)) {
if (fromuser)
{
/*
* Copy the lookahead portion of the buffer that we will use DPI-based
* snaplen calculation
*/
u32 dpi_lookahead_size = DPI_LOOKAHEAD_SIZE;
if (dpi_lookahead_size > val_len)
dpi_lookahead_size = val_len;
if (unlikely(dpi_lookahead_size >= max_arg_size))
return PPM_FAILURE_BUFFER_FULL;
/* Returns the number of bytes NOT read. */
len = (int)ppm_copy_from_user(args->buffer + args->arg_data_offset,
(const void __user *)(syscall_arg_t)val,
dpi_lookahead_size);
if(unlikely(len != 0))
{
goto send_empty_bytebuf_param;
}
/*
* Check if there's more to copy
*/
if (likely((dpi_lookahead_size != val_len))) {
/*
* Calculate the snaplen
*/
if (likely(args->enforce_snaplen)) {
u32 sl = args->consumer->snaplen;
#ifndef UDIG
sl = compute_snaplen(args, args->buffer + args->arg_data_offset, dpi_lookahead_size);
#endif
if (val_len > sl)
val_len = sl;
}
if (unlikely((val_len) >= max_arg_size))
val_len = max_arg_size;
if (val_len > dpi_lookahead_size) {
len = (int)ppm_copy_from_user(args->buffer + args->arg_data_offset + dpi_lookahead_size,
(const uint8_t __user *)(syscall_arg_t)val + dpi_lookahead_size,
val_len - dpi_lookahead_size);
if (unlikely(len != 0))
{
goto send_empty_bytebuf_param;
}
}
}
len = val_len;
}
else
{
if (likely(args->enforce_snaplen)) {
#ifdef UDIG
u32 sl = args->consumer->snaplen;
#else
u32 sl = compute_snaplen(args, (char *)(syscall_arg_t)val, val_len);
#endif
if (val_len > sl)
val_len = sl;
}
if (unlikely(val_len >= max_arg_size))
return PPM_FAILURE_BUFFER_FULL;
memcpy(args->buffer + args->arg_data_offset,
(void *)(syscall_arg_t)val, val_len);
len = val_len;
}
/* If we arrive here we have something to send. */
break;
}
/* Send an empty param in all these cases:
* - we have a null pointer `val==0` or `val_len==0`.
* - we have read `0` bytes.
* - we faced an error while reading.
*/
send_empty_bytebuf_param:
len = 0;
break;
case PT_SOCKADDR:
case PT_SOCKTUPLE:
case PT_FDLIST:
if(likely(val != 0))
{
if (unlikely(val_len >= max_arg_size))
return PPM_FAILURE_BUFFER_FULL;
if(fromuser)
{
len = (int)ppm_copy_from_user(args->buffer + args->arg_data_offset,
(const void __user *)(syscall_arg_t)val,
val_len);
if(unlikely(len != 0))
{
goto send_empty_sock_param;
}
len = val_len;
}
else
{
memcpy(args->buffer + args->arg_data_offset,
(void *)(syscall_arg_t)val, val_len);
len = val_len;
}
/* If we arrive here we have something to send. */
break;
}
send_empty_sock_param:
len = 0;
break;
case PT_FLAGS8:
case PT_ENUMFLAGS8:
case PT_UINT8:
case PT_SIGTYPE:
if (likely(max_arg_size >= sizeof(u8))) {
*(u8 *)(args->buffer + args->arg_data_offset) = (u8)val;
len = sizeof(u8);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_FLAGS16:
case PT_ENUMFLAGS16:
case PT_UINT16:
case PT_SYSCALLID:
if (likely(max_arg_size >= sizeof(u16))) {
*(u16 *)(args->buffer + args->arg_data_offset) = (u16)val;
len = sizeof(u16);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_FLAGS32:
case PT_UINT32:
case PT_MODE:
case PT_UID:
case PT_GID:
case PT_SIGSET:
case PT_ENUMFLAGS32:
if (likely(max_arg_size >= sizeof(u32))) {
*(u32 *)(args->buffer + args->arg_data_offset) = (u32)val;
len = sizeof(u32);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_RELTIME:
case PT_ABSTIME:
case PT_UINT64:
if (likely(max_arg_size >= sizeof(u64))) {
*(u64 *)(args->buffer + args->arg_data_offset) = (u64)val;
len = sizeof(u64);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_INT8:
if (likely(max_arg_size >= sizeof(s8))) {
*(s8 *)(args->buffer + args->arg_data_offset) = (s8)(long)val;
len = sizeof(s8);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_INT16:
if (likely(max_arg_size >= sizeof(s16))) {
*(s16 *)(args->buffer + args->arg_data_offset) = (s16)(long)val;
len = sizeof(s16);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_INT32:
if (likely(max_arg_size >= sizeof(s32))) {
*(s32 *)(args->buffer + args->arg_data_offset) = (s32)(long)val;
len = sizeof(s32);
} else {
return PPM_FAILURE_BUFFER_FULL;
}