ft_strace/srcs/main.c

111 lines
No EOL
3.6 KiB
C

/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* main.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: thrieg <thrieg@student.42mulhouse.fr> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2025/12/11 04:07:30 by thrieg #+# #+# */
/* Updated: 2025/12/11 23:25:15 by thrieg ### ########.fr */
/* */
/* ************************************************************************** */
#include "../includes/ft_strace.h"
int main_loop(size_t binary_type, pid_t pid)
{
int in_syscall = 0;
while (1) {
// Ask kernel to run until next syscall or signal
if (ptrace(PTRACE_SYSCALL, pid, 0, 0) == -1) break;
int status;
if (waitpid(pid, &status, 0) == -1) break;
if (WIFEXITED(status)) {
// child exited normally
printf("+++ exited with %d +++\n", WEXITSTATUS(status));
break;
}
if (WIFSIGNALED(status)) {
// killed by a signal
printf("+++ killed by %s +++\n", strsignal(WTERMSIG(status)));
break;
}
if (!WIFSTOPPED(status))
continue;
int sig = WSTOPSIG(status);
if (sig == (SIGTRAP | 0x80)) {
// syscall-enter or syscall-exit
if (!in_syscall) {
// ENTRY
read_regs_and_print_entry(pid, binary_type);
in_syscall = 1;
} else {
// EXIT
read_regs_and_print_exit(pid, binary_type);
in_syscall = 0;
}
} else {
// A real signal: print it
print_signal(pid, sig);
// pass down the signal to the actual program
if (ptrace(PTRACE_SYSCALL, pid, 0, sig) == -1) break;
//waitpid(pid, &status, 0);
}
}
return (EXIT_SUCCESS);
}
int main(int argc, char **argv)
{
if (argc < 2)
{
dprintf(2, "usage: %s <path/to/program> <arg1> <arg2> ...\n", argv[0]);
return (EXIT_FAILURE);
}
//determine if this file is an executable, and if so, 64 or 32 bits
ssize_t binary_bits = binary_type(argv[1]);
if (binary_bits < 0)
{
if (binary_bits == -1)
{
dprintf(2, "couldn't read that file, make sure you have the read and execute permissions on %s\n", argv[1]);
}
else if (binary_bits == -2)
{
dprintf(2, "%s is not a supported binary\n", argv[1]);
}
return (EXIT_FAILURE);
}
pid_t pid = fork();
if (pid == 0) {
execvp(argv[1], argv + 1);
perror("execvp");
return (EXIT_FAILURE);
}
else {
// 1) Seize the child
if (ptrace(PTRACE_SEIZE, pid, 0, 0) == -1) perror("PTRACE_SEIZE");
// 2) Interrupt it to force a stop
if (ptrace(PTRACE_INTERRUPT, pid, 0, 0) == -1) perror("PTRACE_INTERRUPT");
// 3) Wait for it to stop
int status;
waitpid(pid, &status, 0);
// 4) Set options
long opts = PTRACE_O_TRACESYSGOOD;
ptrace(PTRACE_SETOPTIONS, pid, 0, opts);
// 5) Enter main trace loop
return (main_loop((size_t)binary_bits, pid));
}
return (EXIT_SUCCESS);
}