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#include <errno.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ptrace.h>
#include <sys/types.h>
#include <unistd.h>
#include "config.h"
#include "log.h"
#include "ptrace_utils.h"
#include "tracer.h"
static long tracee_getword(pid_t tid, const void *addr)
{
long res;
errno = 0;
res = ptrace(PTRACE_PEEKDATA, tid, addr, NULL);
if(errno)
{
/* LCOV_EXCL_START : We only do that on things that went through the
* kernel successfully, and so should be valid. The exception is
* execve(), which will dup arguments when entering the syscall */
log_error(tid, "tracee_getword() failed: %s", strerror(errno));
return 0;
/* LCOV_EXCL_STOP */
}
return res;
}
void *tracee_getptr(int mode, pid_t tid, const void *addr)
{
if(mode == MODE_I386)
{
/* Pointers are 32 bits */
uint32_t ptr;
tracee_read(tid, (void*)&ptr, addr, sizeof(ptr));
return (void*)(uint64_t)ptr;
}
else /* mode == MODE_X86_64 */
{
/* Pointers are 64 bits */
uint64_t ptr;
tracee_read(tid, (void*)&ptr, addr, sizeof(ptr));
return (void*)ptr;
}
}
uint64_t tracee_getlong(int mode, pid_t tid, const void *addr)
{
if(mode == MODE_I386)
{
/* Longs are 32 bits */
uint32_t val;
tracee_read(tid, (void*)&val, addr, sizeof(val));
return (uint64_t)val;
}
else /* mode == MODE_X86_64 */
{
/* Longs are 64 bits */
uint64_t val;
tracee_read(tid, (void*)&val, addr, sizeof(val));
return val;
}
}
uint64_t tracee_getu64(pid_t tid, const void *addr)
{
/* Longs are 64 bits */
uint64_t val;
tracee_read(tid, (void*)&val, addr, sizeof(val));
return val;
}
size_t tracee_getwordsize(int mode)
{
if(mode == MODE_I386)
/* Pointers are 32 bits */
return 4;
else /* mode == MODE_X86_64 */
/* Pointers are 64 bits */
return 8;
}
size_t tracee_strlen(pid_t tid, const char *str)
{
uintptr_t ptr = (uintptr_t)str;
size_t j = ptr % WORD_SIZE;
uintptr_t i = ptr - j;
size_t size = 0;
int done = 0;
for(; !done; i += WORD_SIZE)
{
unsigned long data = tracee_getword(tid, (const void*)i);
for(; !done && j < WORD_SIZE; ++j)
{
unsigned char byte = data >> (8 * j);
if(byte == 0)
done = 1;
else
++size;
}
j = 0;
}
return size;
}
void tracee_read(pid_t tid, char *dst, const char *src, size_t size)
{
uintptr_t ptr = (uintptr_t)src;
size_t j = ptr % WORD_SIZE;
uintptr_t i = ptr - j;
uintptr_t end = ptr + size;
for(; i < end; i += WORD_SIZE)
{
unsigned long data = tracee_getword(tid, (const void*)i);
for(; j < WORD_SIZE && i + j < end; ++j)
*dst++ = data >> (8 * j);
j = 0;
}
}
char *tracee_strdup(pid_t tid, const char *str)
{
size_t length = tracee_strlen(tid, str);
char *res = malloc(length + 1);
tracee_read(tid, res, str, length);
res[length] = '\0';
return res;
}
char **tracee_strarraydup(int mode, pid_t tid, const char *const *argv)
{
/* FIXME : This is probably broken on x32 */
char **array;
/* Reads number of pointers in pointer array */
size_t nb_args = 0;
{
const char *const *a = argv;
/* xargv = *a */
const char *xargv = tracee_getptr(mode, tid, a);
while(xargv != NULL)
{
++nb_args;
++a;
xargv = tracee_getptr(mode, tid, a);
}
}
/* Allocs pointer array */
array = malloc((nb_args + 1) * sizeof(char*));
/* Dups array elements */
{
size_t i = 0;
/* xargv = argv[0] */
const char *xargv = tracee_getptr(mode, tid, argv);
while(xargv != NULL)
{
array[i] = tracee_strdup(tid, xargv);
++i;
/* xargv = argv[i] */
xargv = tracee_getptr(mode, tid, argv + i);
}
array[i] = NULL;
}
return array;
}
void free_strarray(char **array)
{
char **ptr = array;
while(*ptr)
{
free(*ptr);
++ptr;
}
free(array);
}
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