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Merge pull request #78 from PartialVolume/reduce_log_allocation_memory_requirements

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Fix log message buffer overflow & reduce memory requirements.
This commit is contained in:
Martijn van Brummelen
2018-11-22 07:06:29 +01:00
committed by GitHub
parent 99778f187d 5f712f3b0c
commit ae51d548d4
2 changed files with 139 additions and 59 deletions
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195
src/logging.c
View File

@@ -27,8 +27,6 @@
#include "options.h"
#include "logging.h"
int const MAX_LOG_LINE_CHARS = 512;
/* Global array to hold log values to print when logging to STDOUT */
char **log_lines;
int log_current_element = 0;
@@ -44,6 +42,10 @@ void nwipe_log( nwipe_log_t level, const char* format, ... )
char **result;
char *malloc_result;
char message_buffer[MAX_LOG_LINE_CHARS * sizeof(char)];
int chars_written;
int message_buffer_length;
/* A time buffer. */
time_t t;
@@ -57,6 +59,135 @@ void nwipe_log( nwipe_log_t level, const char* format, ... )
pthread_mutex_lock( &mutex1 );
/* Position of writing to current log string */
int line_current_pos = 0;
/* Print the date. The rc script uses the same format. */
chars_written = snprintf( message_buffer, MAX_LOG_LINE_CHARS, "[%i/%02i/%02i %02i:%02i:%02i] nwipe: ", \
1900 + p->tm_year, 1 + p->tm_mon, p->tm_mday, p->tm_hour, p->tm_min, p->tm_sec );
/* Has the end of the buffer been reached ?, snprintf returns the number of characters that would have been
* written if MAX_LOG_LINE_CHARS had not been reached, it does not return the actual characters written in
* all circumstances, hence why we need to check whether it's greater than MAX_LOG_LINE_CHARS and if so set
* it to MAX_LOG_LINE_CHARS, preventing a buffer overrun further down this function.
*/
/* check if there was a complete failure to write this part of the message, in which case return */
if ( chars_written < 0 )
{
fprintf( stderr, "nwipe_log: snprintf error when writing log line to memory.\n" );
pthread_mutex_unlock( &mutex1 );
return;
}
else
{
if ( (line_current_pos + chars_written) > MAX_LOG_LINE_CHARS )
{
fprintf( stderr, "nwipe_log: Warning! The log line has been truncated as it exceeded %i characters\n", MAX_LOG_LINE_CHARS );
line_current_pos = MAX_LOG_LINE_CHARS;
}
else
{
line_current_pos += chars_written;
}
}
if ( line_current_pos < MAX_LOG_LINE_CHARS )
{
switch( level )
{
case NWIPE_LOG_NONE:
/* Do nothing. */
break;
case NWIPE_LOG_DEBUG:
chars_written = snprintf( message_buffer + line_current_pos, MAX_LOG_LINE_CHARS - line_current_pos, "debug: " );
break;
case NWIPE_LOG_INFO:
chars_written = snprintf( message_buffer + line_current_pos, MAX_LOG_LINE_CHARS - line_current_pos, "info: " );
break;
case NWIPE_LOG_NOTICE:
chars_written = snprintf( message_buffer + line_current_pos, MAX_LOG_LINE_CHARS - line_current_pos, "notice: " );
break;
case NWIPE_LOG_WARNING:
chars_written = snprintf( message_buffer + line_current_pos, MAX_LOG_LINE_CHARS - line_current_pos, "warning: " );
break;
case NWIPE_LOG_ERROR:
chars_written = snprintf( message_buffer + line_current_pos, MAX_LOG_LINE_CHARS - line_current_pos, "error: " );
break;
case NWIPE_LOG_FATAL:
chars_written = snprintf( message_buffer + line_current_pos, MAX_LOG_LINE_CHARS - line_current_pos, "fatal: " );
break;
case NWIPE_LOG_SANITY:
/* TODO: Request that the user report the log. */
chars_written = snprintf( message_buffer + line_current_pos, MAX_LOG_LINE_CHARS - line_current_pos, "sanity: " );
break;
default:
chars_written = snprintf( message_buffer + line_current_pos, MAX_LOG_LINE_CHARS - line_current_pos, "level %i: ", level );
}
/* Has the end of the buffer been reached ?
*/
if ( chars_written < 0 )
{
fprintf( stderr, "nwipe_log: snprintf error when writing log line to memory.\n" );
pthread_mutex_unlock( &mutex1 );
return;
}
else
{
if ( (line_current_pos + chars_written) > MAX_LOG_LINE_CHARS )
{
fprintf( stderr, "nwipe_log: Warning! The log line has been truncated as it exceeded %i characters\n", MAX_LOG_LINE_CHARS );
line_current_pos = MAX_LOG_LINE_CHARS;
}
else
{
line_current_pos += chars_written;
}
}
}
/* The variable argument pointer. */
va_list ap;
/* Fetch the argument list. */
va_start( ap, format );
/* Print the event. */
if ( line_current_pos < MAX_LOG_LINE_CHARS )
{
chars_written = vsnprintf( message_buffer + line_current_pos, MAX_LOG_LINE_CHARS - line_current_pos -1, format, ap );
if ( chars_written < 0 )
{
fprintf( stderr, "nwipe_log: snprintf error when writing log line to memory.\n" );
pthread_mutex_unlock( &mutex1 );
return;
}
else
{
if ( (line_current_pos + chars_written) > MAX_LOG_LINE_CHARS )
{
fprintf( stderr, "nwipe_log: Warning! The log line has been truncated as it exceeded %i characters\n", MAX_LOG_LINE_CHARS );
line_current_pos = MAX_LOG_LINE_CHARS;
}
else
{
line_current_pos += chars_written;
}
}
}
/* Increase the current log element pointer - we will write here */
if (log_current_element == log_elements_allocated) {
log_elements_allocated++;
@@ -69,7 +200,8 @@ void nwipe_log( nwipe_log_t level, const char* format, ... )
}
log_lines = result;
malloc_result = malloc(MAX_LOG_LINE_CHARS * sizeof(char));
message_buffer_length = strlen( message_buffer ) * sizeof(char);
malloc_result = malloc((message_buffer_length + 1) * sizeof(char));
if (malloc_result == NULL)
{
fprintf( stderr, "nwipe_log: malloc failed when adding a log line.\n" );
@@ -79,62 +211,7 @@ void nwipe_log( nwipe_log_t level, const char* format, ... )
log_lines[log_current_element] = malloc_result;
}
/* Position of writing to current log string */
int line_current_pos = 0;
/* Print the date. The rc script uses the same format. */
line_current_pos = snprintf( log_lines[log_current_element], MAX_LOG_LINE_CHARS, "[%i/%02i/%02i %02i:%02i:%02i] nwipe: ", \
1900 + p->tm_year, 1 + p->tm_mon, p->tm_mday, p->tm_hour, p->tm_min, p->tm_sec );
switch( level )
{
case NWIPE_LOG_NONE:
/* Do nothing. */
break;
case NWIPE_LOG_DEBUG:
line_current_pos += snprintf( log_lines[log_current_element] + line_current_pos, MAX_LOG_LINE_CHARS, "debug: " );
break;
case NWIPE_LOG_INFO:
line_current_pos += snprintf( log_lines[log_current_element] + line_current_pos, MAX_LOG_LINE_CHARS, "info: " );
break;
case NWIPE_LOG_NOTICE:
line_current_pos += snprintf( log_lines[log_current_element] + line_current_pos, MAX_LOG_LINE_CHARS, "notice: " );
break;
case NWIPE_LOG_WARNING:
line_current_pos += snprintf( log_lines[log_current_element] + line_current_pos, MAX_LOG_LINE_CHARS, "warning: " );
break;
case NWIPE_LOG_ERROR:
line_current_pos += snprintf( log_lines[log_current_element] + line_current_pos, MAX_LOG_LINE_CHARS, "error: " );
break;
case NWIPE_LOG_FATAL:
line_current_pos += snprintf( log_lines[log_current_element] + line_current_pos, MAX_LOG_LINE_CHARS, "fatal: " );
break;
case NWIPE_LOG_SANITY:
/* TODO: Request that the user report the log. */
line_current_pos += snprintf( log_lines[log_current_element] + line_current_pos, MAX_LOG_LINE_CHARS, "sanity: " );
break;
default:
line_current_pos += snprintf( log_lines[log_current_element] + line_current_pos, MAX_LOG_LINE_CHARS, "level %i: ", level );
}
/* The variable argument pointer. */
va_list ap;
/* Fetch the argument list. */
va_start( ap, format );
/* Print the event. */
line_current_pos += vsnprintf( log_lines[log_current_element] + line_current_pos, MAX_LOG_LINE_CHARS, format, ap );
strcpy ( log_lines[log_current_element], message_buffer );
/*
if( level >= NWIPE_LOG_WARNING )

3
src/logging.h
View File

@@ -22,6 +22,9 @@
#ifndef LOGGING_H_
#define LOGGING_H_
/* Maximum size a log message can be */
#define MAX_LOG_LINE_CHARS 512
typedef enum nwipe_log_t_
{
NWIPE_LOG_NONE = 0,