xrdp/libipm/libipm_recv.c

695 lines
19 KiB
C

/**
* Copyright (C) 2022 Matt Burt, all xrdp contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file libipm/libipm.c
* @brief Inter-Process Messaging building and parsing definitions
*/
#if defined(HAVE_CONFIG_H)
#include <config_ac.h>
#endif
#include <stdio.h>
#include <stdarg.h>
#include "libipm.h"
#include "libipm_private.h"
#include "libipm_facilities.h"
#include "trans.h"
#include "log.h"
#include "os_calls.h"
#include "string_calls.h"
/**************************************************************************//**
* Checks the message header in the input stream, and gets the size
*/
static enum libipm_status
validate_msg_header(struct trans *trans, int *size)
{
struct libipm_priv *priv = (struct libipm_priv *)trans->extra_data;
enum libipm_status rv = E_LI_BAD_HEADER;
int version;
int facility;
int reserved;
in_uint16_le(trans->in_s, version);
in_uint16_le(trans->in_s, *size);
in_uint16_le(trans->in_s, facility);
in_uint16_le(trans->in_s, priv->in_msgno);
in_uint32_le(trans->in_s, reserved);
if (version != LIBIPM_VERSION)
{
LOG(LOG_LEVEL_ERROR,
"Unexpected version number %d from IPM", version);
}
else if (*size < HEADER_SIZE || *size > LIBIPM_MAX_MSG_SIZE)
{
LOG(LOG_LEVEL_ERROR,
"Invalid message length %d from IPM", *size);
}
else if (facility != priv->facility)
{
LOG(LOG_LEVEL_ERROR,
"Invalid facility %d from IPM - expected %d",
facility, priv->facility);
}
else if (reserved != 0)
{
LOG(LOG_LEVEL_ERROR,
"Invalid reserved field %d from IPM", reserved);
}
else
{
rv = E_LI_SUCCESS;
}
return rv;
}
/*****************************************************************************/
enum libipm_status
libipm_msg_in_check_available(struct trans *trans, int *available)
{
enum libipm_status rv = E_LI_SUCCESS;
*available = 0;
if (trans == NULL || trans->extra_data == NULL)
{
LOG_DEVEL(LOG_LEVEL_ERROR, "Failed devel check");
rv = E_LI_PROGRAM_ERROR;
}
else if (trans->status != TRANS_STATUS_UP)
{
rv = E_LI_PROGRAM_ERROR; /* Caller should have checked this */
}
else
{
unsigned int len = trans->in_s->end - trans->in_s->data; /* Data read so far */
if (len == trans->header_size)
{
if (trans->extra_flags == 0)
{
/* We've read the header so far - validate it */
int size;
rv = validate_msg_header(trans, &size);
if (rv == 0)
{
/* Header is OK */
trans->extra_flags = 1;
trans->header_size = size;
*available = (size == HEADER_SIZE);
}
}
else
{
*available = 1;
}
}
}
return rv;
}
/*****************************************************************************/
enum libipm_status
libipm_msg_in_wait_available(struct trans *trans)
{
tbus wobj[1];
int ocnt = 0;
enum libipm_status rv = E_LI_SUCCESS;
if (trans == NULL || trans->extra_data == NULL ||
trans->status != TRANS_STATUS_UP)
{
LOG_DEVEL(LOG_LEVEL_ERROR, "Failed devel check");
rv = E_LI_PROGRAM_ERROR;
}
else if (trans_get_wait_objs(trans, wobj, &ocnt) != 0)
{
LOG(LOG_LEVEL_ERROR, "Can't get wait object for libipm transport");
rv = E_LI_TRANSPORT_ERROR;
}
else
{
int gotmsg = 0;
/* Prevent trans_check_wait_objs() actioning any callcacks
* when the message is complete */
ttrans_data_in saved_trans_data_in = trans->trans_data_in;
trans->trans_data_in = NULL;
while (rv == E_LI_SUCCESS && !gotmsg)
{
if (g_obj_wait(wobj, ocnt, NULL, 0, -1) != 0)
{
LOG(LOG_LEVEL_ERROR, "Error waiting on libipm transport");
rv = E_LI_TRANSPORT_ERROR;
}
else if (trans_check_wait_objs(trans) != 0)
{
LOG(LOG_LEVEL_ERROR, "Error reading libipm transport");
rv = E_LI_TRANSPORT_ERROR;
}
else
{
/* This call logs errors already */
rv = libipm_msg_in_check_available(trans, &gotmsg);
}
}
/* Restore transport callback operation */
trans->trans_data_in = saved_trans_data_in;
}
return rv;
}
/*****************************************************************************/
unsigned short
libipm_msg_in_get_msgno(const struct trans *trans)
{
struct libipm_priv *priv = (struct libipm_priv *)trans->extra_data;
return (priv == NULL) ? 0 : priv->in_msgno;
}
/*****************************************************************************/
char
libipm_msg_in_peek_type(struct trans *trans)
{
int result;
if (s_check_rem(trans->in_s, 1))
{
char c;
in_uint8_peek(trans->in_s, c);
if (g_strchr(libipm_valid_type_chars, c) != NULL)
{
result = c; /* Only return valid characters */
}
else
{
result = '?';
}
}
else
{
result = '\0';
}
return result;
}
/**************************************************************************//**
* Log an input parsing error
*
* @param trans libipm transport
* @param format printf-like format descriptor
*/
printflike(2, 3) static void
log_parse_error(struct trans *trans, const char *format, ...)
{
struct libipm_priv *priv = (struct libipm_priv *)trans->extra_data;
const char *msgno_str = NULL;
char msgno_str_buff[32];
char buff[256];
unsigned int len;
/* Find a string for the message number */
if (priv->msgno_to_str != NULL)
{
msgno_str = priv->msgno_to_str(priv->in_msgno);
}
if (msgno_str == NULL)
{
g_snprintf(msgno_str_buff, sizeof(msgno_str_buff),
"[code #%d]", priv->in_msgno);
msgno_str = msgno_str_buff;
}
len = g_snprintf(buff, sizeof(buff),
"Error parsing ipm message for %s, parameter %d :",
msgno_str, priv->in_param_count);
if (len < sizeof(buff))
{
va_list ap;
va_start(ap, format);
vsnprintf(&buff[len], sizeof(buff) - len, format, ap);
va_end(ap);
}
LOG(LOG_LEVEL_ERROR, "%s", buff);
}
/* Common format string for overflow reporting */
static const char *
not_enough_input_msg = "Input buffer overflow for '%c'";
/**************************************************************************//**
* Extract a bool from the input stream
*
* @param c Type letter which triggered the call
* @param trans libipm transport
* @param argptr Pointer to pointer to receive the value
* @return != 0 for error
*
* The value must be a 0 or 1 on-the-wire, or an error is returned.
*/
static enum libipm_status
extract_bool_type(char c, struct trans *trans, va_list *argptr)
{
enum libipm_status rv = E_LI_SUCCESS;
struct stream *s = trans->in_s;
int b;
if (!s_check_rem(s, 1))
{
log_parse_error(trans, not_enough_input_msg, c);
rv = E_LI_BUFFER_OVERFLOW;
}
else
{
in_uint8(s, b);
if (b < 0 || b > 1)
{
log_parse_error(trans, "Boolean has value other than 0/1");
rv = E_LI_BAD_VALUE;
}
else
{
int *tmp = va_arg(*argptr, int *);
*tmp = b;
}
}
return rv;
}
/**************************************************************************//**
* Extract an octet from the input stream
*
* @param c Type letter which triggered the call
* @param trans libipm transport
* @param argptr argptr to pointer to receive the value
* @return != 0 for error
*/
static enum libipm_status
extract_int8_type(char c, struct trans *trans, va_list *argptr)
{
enum libipm_status rv = E_LI_SUCCESS;
struct stream *s = trans->in_s;
if (!s_check_rem(s, 1))
{
log_parse_error(trans, not_enough_input_msg, c);
rv = E_LI_BUFFER_OVERFLOW;
}
else
{
unsigned char *tmp = va_arg(*argptr, unsigned char *);
in_uint8(s, *tmp);
}
return rv;
}
/**************************************************************************//**
* Extract a 16-bit integer from the input stream
*
* @param c Type letter which triggered the call
* @param trans libipm transport
* @param argptr argptr to pointer to receive the value
* @return != 0 for error
*/
static enum libipm_status
extract_int16_type(char c, struct trans *trans, va_list *argptr)
{
enum libipm_status rv = E_LI_SUCCESS;
struct stream *s = trans->in_s;
if (!s_check_rem(s, 2))
{
log_parse_error(trans, not_enough_input_msg, c);
rv = E_LI_BUFFER_OVERFLOW;
}
else
{
uint16_t *tmp = va_arg(*argptr, uint16_t *);
/*
* C99 7.18.1.1 requires int16_t (if present) to be a two's
* complement representation, so this line is valid for both
* int16_t and uint16_t */
in_uint16_le(s, *tmp);
}
return rv;
}
/**************************************************************************//**
* Extract a 32-bit integer from the input stream
*
* @param c Type letter which triggered the call
* @param trans libipm transport
* @param argptr argptr to pointer to receive the value
* @return != 0 for error
*/
static enum libipm_status
extract_int32_type(char c, struct trans *trans, va_list *argptr)
{
enum libipm_status rv = E_LI_SUCCESS;
struct stream *s = trans->in_s;
if (!s_check_rem(s, 4))
{
log_parse_error(trans, not_enough_input_msg, c);
rv = E_LI_BUFFER_OVERFLOW;
}
else
{
uint32_t *tmp = va_arg(*argptr, uint32_t *);
/*
* C99 7.18.1.1 requires int32_t (if present) to be a two's
* complement representation, so this line is valid for both
* int32_t and uint32_t */
in_uint32_le(s, *tmp);
}
return rv;
}
/**************************************************************************//**
* Extract a 64-bit integer from the input stream
*
* @param c Type letter which triggered the call
* @param trans libipm transport
* @param argptr argptr to pointer to receive the value
* @return != 0 for error
*/
static enum libipm_status
extract_int64_type(char c, struct trans *trans, va_list *argptr)
{
enum libipm_status rv = E_LI_SUCCESS;
struct stream *s = trans->in_s;
if (!s_check_rem(s, 8))
{
log_parse_error(trans, not_enough_input_msg, c);
rv = E_LI_BUFFER_OVERFLOW;
}
else
{
uint64_t *tmp = va_arg(*argptr, uint64_t *);
/*
* C99 7.18.1.1 requires int64_t (if present) to be a two's
* complement representation, so this line is valid for both
* int64_t and uint64_t */
in_uint64_le(s, *tmp);
}
return rv;
}
/**************************************************************************//**
* Extract a char * pointer from the input stream
*
* @param c Type letter which triggered the call
* @param trans libipm transport
* @param argptr argptr to pointer to receive the value
* @return != 0 for error
*/
static enum libipm_status
extract_char_ptr_type(char c, struct trans *trans, va_list *argptr)
{
enum libipm_status rv = E_LI_SUCCESS;
struct stream *s = trans->in_s;
/* Look for a string terminator in the rest of the input stream */
char *termptr = g_strnchr(s->p, '\0', s->end - s->p);
if (termptr == NULL)
{
log_parse_error(trans, "Unterminated string value");
rv = E_LI_BAD_VALUE;
}
else
{
char **tmp = va_arg(*argptr, char **);
*tmp = s->p;
s->p = termptr + 1;
}
return rv;
}
/**************************************************************************//**
* Extract a file descriptor from the input stream
*
* @param c Type letter which triggered the call
* @param trans libipm transport
* @param argptr argptr to pointer to receive the value
* @return != 0 for error
*/
static enum libipm_status
extract_fd_type(char c, struct trans *trans, va_list *argptr)
{
enum libipm_status rv = E_LI_SUCCESS;
struct libipm_priv *priv = (struct libipm_priv *)trans->extra_data;
/* File descriptor available? */
if (priv->in_fd_index >= priv->in_fd_count)
{
log_parse_error(trans, "No file descriptors available");
rv = E_LI_TOO_MANY_FDS;
}
else
{
int *tmp = va_arg(*argptr, int *);
*tmp = priv->in_fds[priv->in_fd_index++];
}
return rv;
}
/**************************************************************************//**
* Extract a fixed size block from the input stream
*
* @param c Type letter which triggered the call
* @param trans libipm transport
* @param argptr argptr to pointer to block descriptor
* @return != 0 for error
*/
static enum libipm_status
extract_fsb_type(char c, struct trans *trans, va_list *argptr)
{
enum libipm_status rv = E_LI_SUCCESS;
struct stream *s = trans->in_s;
const struct libipm_fsb *fsb = va_arg(*argptr, const struct libipm_fsb *);
if (fsb == NULL || fsb->data == NULL)
{
log_parse_error(trans, "Malformed descriptor for '%c'", c);
rv = E_LI_PROGRAM_ERROR;
}
else if (!s_check_rem(s, 2))
{
log_parse_error(trans, not_enough_input_msg, c);
rv = E_LI_BUFFER_OVERFLOW;
}
else
{
unsigned int len;
in_uint16_le(s, len);
if (len != fsb->datalen)
{
log_parse_error(trans, "Type '%c'. Expected %u bytes, but got %u",
c, fsb->datalen, len);
rv = E_LI_BAD_VALUE;
}
else if (!s_check_rem(s, len))
{
log_parse_error(trans, not_enough_input_msg, c);
rv = E_LI_BUFFER_OVERFLOW;
}
else
{
in_uint8a(s, fsb->data, len);
rv = E_LI_SUCCESS;
}
}
return rv;
}
/**************************************************************************//**
* Local function to pull data from the input stream
*
* @param trans libipm transport
* @param format type-system compatible string
* @param argptr Pointers to variables to receive extracted data
* @pre - trans->priv has been checked to be non-NULL
* @return != 0 for error
*/
static enum libipm_status
libipm_msg_in_parsev(struct trans *trans, const char *format, va_list *argptr)
{
enum libipm_status rv = E_LI_SUCCESS;
struct stream *s = trans->in_s;
struct libipm_priv *priv = (struct libipm_priv *)trans->extra_data;
const char *cp;
if (format != NULL)
{
for (cp = format; rv == 0 && *cp != '\0' ; ++cp)
{
char c = *cp;
char actual_c;
++priv->in_param_count; /* Count the parameter */
/* Check the type of the input is supported */
if (g_strchr(libipm_valid_type_chars, c) == NULL)
{
log_parse_error(trans,
"Type code '%c' is not supported", c);
rv = E_LI_UNSUPPORTED_TYPE;
break;
}
/* Check the type of the input matches the stream */
if (!s_check_rem(s, 1))
{
log_parse_error(trans, not_enough_input_msg, c);
rv = E_LI_BUFFER_OVERFLOW;
break;
}
in_uint8(s, actual_c);
if (c != actual_c)
{
log_parse_error(trans, "Expected '%c', got '%c'", c, actual_c);
rv = E_LI_UNEXPECTED_TYPE;
break;
}
switch (c)
{
case 'y':
rv = extract_int8_type(c, trans, argptr);
break;
case 'b':
rv = extract_bool_type(c, trans, argptr);
break;
case 'n':
case 'q':
rv = extract_int16_type(c, trans, argptr);
break;
case 'i':
case 'u':
rv = extract_int32_type(c, trans, argptr);
break;
case 'x':
case 't':
rv = extract_int64_type(c, trans, argptr);
break;
case 's':
rv = extract_char_ptr_type(c, trans, argptr);
break;
case 'h':
rv = extract_fd_type(c, trans, argptr);
break;
case 'B':
rv = extract_fsb_type(c, trans, argptr);
break;
default:
log_parse_error(trans,
"Reserved type code '%c' "
"is unimplemented", c);
rv = E_LI_UNIMPLEMENTED_TYPE;
break;
}
}
}
return rv;
}
/*****************************************************************************/
enum libipm_status
libipm_msg_in_parse(struct trans *trans, const char *format, ...)
{
enum libipm_status rv;
struct libipm_priv *priv = (struct libipm_priv *)trans->extra_data;
if (priv == NULL)
{
LOG_DEVEL(LOG_LEVEL_ERROR, "uninitialised transport");
rv = E_LI_PROGRAM_ERROR;
}
else
{
va_list argptr;
va_start(argptr, format);
rv = libipm_msg_in_parsev(trans, format, &argptr);
va_end(argptr);
}
return rv;
}
/*****************************************************************************/
void
libipm_msg_in_reset(struct trans *trans)
{
struct libipm_priv *priv = (struct libipm_priv *)trans->extra_data;
if (priv == NULL)
{
LOG_DEVEL(LOG_LEVEL_ERROR, "uninitialised transport");
}
else
{
if ((priv->flags & LIBIPM_E_MSG_IN_ERASE_AFTER_USE) != 0)
{
struct stream *s = trans->in_s;
g_memset(s->data, '\0', s->end - s->data);
priv->flags &= ~LIBIPM_E_MSG_IN_ERASE_AFTER_USE;
}
priv->in_msgno = 0;
priv->in_param_count = 0;
libipm_msg_in_close_file_descriptors(trans);
}
trans->extra_flags = 0;
trans->header_size = HEADER_SIZE;
trans->no_stream_init_on_data_in = 1;
init_stream(trans->in_s, LIBIPM_MAX_MSG_SIZE);
}