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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <asm/unistd.h>
#include "i386.h"
#include "ltrace.h"
#include "process.h"
#include "symbols.h"
#include "functions.h"
#include "syscall.h"
#include "signal.h"
#include "output.h"
struct process * list_of_processes = NULL;
unsigned int instruction_pointer;
int execute_process(const char * file, char * const argv[])
{
int pid = fork();
if (pid<0) {
perror("fork");
exit(1);
} else if (!pid) {
trace_me();
execvp(file, argv);
fprintf(stderr, "Can't execute \"%s\": %s\n", argv[1], sys_errlist[errno]);
exit(1);
}
return pid;
}
struct process * attach_process(int pid)
{
struct process * tmp;
tmp = (struct process *)malloc(sizeof(struct process));
tmp->pid = pid;
tmp->syscall_number = -1;
tmp->next = list_of_processes;
list_of_processes = tmp;
return tmp;
}
/*
* TODO: All the breakpoints should be disabled.
*/
void detach_process(int pid)
{
struct process *tmp, *tmp2;
if (list_of_processes && (pid == list_of_processes->pid)) {
tmp2 = list_of_processes->next;
free(list_of_processes);
list_of_processes = tmp2;
} else {
tmp = list_of_processes;
while(tmp && tmp->next) {
if (pid == tmp->next->pid) {
tmp2 = tmp->next->next;
free(tmp->next);
tmp->next = tmp2;
}
tmp = tmp->next;
}
}
if (!kill(pid,0)) {
untrace_pid(pid);
}
}
struct process * pid2proc(int pid)
{
struct process * tmp;
tmp = list_of_processes;
while(tmp) {
if (pid == tmp->pid) {
return tmp;
}
tmp = tmp->next;
}
return NULL;
}
static void chld_handler();
void init_sighandler(void)
{
signal(SIGCHLD, chld_handler);
}
static void chld_handler()
{
int pid;
unsigned long eip;
int esp;
int function_seen;
int status;
struct library_symbol * tmp = NULL;
struct process * current_process;
signal(SIGCHLD, chld_handler);
pid = wait4(-1, &status, WNOHANG, NULL);
if (!pid) {
if (errno!=0) {
perror("wait4");
exit(1);
}
return;
}
if (pid==-1) {
perror("wait4");
exit(1);
}
current_process = pid2proc(pid);
if (!current_process) {
/*
* I should assume here that this process is new, so I
* have to enable breakpoints
*/
if (opt_d>0) {
fprintf(output, "new process %d. Attaching it...\n", pid);
}
current_process = attach_process(pid);
if (opt_d>0) {
fprintf(output, "Enabling breakpoints for pid %d...\n", pid);
}
enable_all_breakpoints(pid);
}
if (WIFEXITED(status)) {
fprintf(output, "pid %u exited\n", pid);
detach_process(pid);
return;
}
if (WIFSIGNALED(status)) {
fprintf(output, "pid %u exited on signal %u\n", pid, WTERMSIG(status));
detach_process(pid);
return;
}
if (!WIFSTOPPED(status)) {
fprintf(output, "pid %u ???\n", pid);
exit(1);
}
eip = get_eip(pid);
instruction_pointer = eip;
if (WSTOPSIG(status) != SIGTRAP) {
send_line("--- %s (%s) ---\n", signal_name[WSTOPSIG(status)], strsignal(WSTOPSIG(status)));
continue_process(pid, WSTOPSIG(status));
return;
}
if (opt_d>0) {
fprintf(output, "<pid:%u> ", pid);
}
switch (type_of_stop(current_process, &status)) {
case PROC_SYSCALL:
if (status==__NR_fork) {
disable_all_breakpoints(pid);
}
if (opt_S) {
send_line("SYSCALL: %s()\n", syscall_list[status]);
}
continue_process(pid, 0);
return;
case PROC_SYSRET:
if (status==__NR_fork) {
enable_all_breakpoints(pid);
}
if (opt_S && (opt_d>0)) {
send_line("SYSRET: %u\n", status);
}
continue_process(pid, 0);
return;
case PROC_BREAKPOINT:
default:
}
/* pid is breakpointed... */
/* TODO: I may be here after a PTRACE_SINGLESTEP ... */
esp = get_esp(pid);
instruction_pointer = get_return(pid, esp);
send_line("");
tmp = library_symbols;
function_seen = 0;
while(tmp) {
if (eip == tmp->addr) {
function_seen = 1;
print_function(tmp->name, pid, esp);
continue_after_breakpoint(pid, eip, tmp->old_value, 0);
break;
}
tmp = tmp->next;
}
if (!function_seen) {
fprintf(output, "pid %u stopped; continuing it...\n", pid);
continue_process(pid, 0);
}
}
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