106 lines
1.7 KiB
C++
106 lines
1.7 KiB
C++
#include <BAN/String.h>
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#include <BAN/Optional.h>
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#include <BAN/Vector.h>
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#include <ctype.h>
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#include <fcntl.h>
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#include <pwd.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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void initialize_stdio()
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{
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const char* tty = "/dev/tty0";
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if (open(tty, O_RDONLY | O_TTY_INIT) != 0) _exit(1);
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if (open(tty, O_WRONLY) != 1) _exit(1);
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if (open(tty, O_WRONLY) != 2) _exit(1);
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}
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int main()
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{
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initialize_stdio();
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if (signal(SIGINT, [](int) {}) == SIG_ERR)
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perror("signal");
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bool first = true;
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while (true)
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{
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char name_buffer[128];
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while (!first)
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{
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printf("username: ");
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fflush(stdout);
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size_t nread = fread(name_buffer, 1, sizeof(name_buffer) - 1, stdin);
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if (nread == 0)
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{
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if (ferror(stdin))
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{
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fprintf(stderr, "Could not read from stdin\n");
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return 1;
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}
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continue;
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}
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if (nread <= 1 || name_buffer[nread - 1] != '\n')
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continue;
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name_buffer[nread - 1] = '\0';
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break;
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}
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if (first)
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{
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strcpy(name_buffer, "user");
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first = false;
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}
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auto* pwd = getpwnam(name_buffer);
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if (pwd == nullptr)
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continue;
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pid_t pid = fork();
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if (pid == 0)
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{
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pid_t pgrp = setpgrp();
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if (tcsetpgrp(0, pgrp) == -1)
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{
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perror("tcsetpgrp");
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exit(1);
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}
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printf("Welcome back %s!\n", pwd->pw_name);
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if (setgid(pwd->pw_gid) == -1)
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perror("setgid");
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if (setuid(pwd->pw_uid) == -1)
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perror("setuid");
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setenv("HOME", pwd->pw_dir, 1);
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chdir(pwd->pw_dir);
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execl(pwd->pw_shell, pwd->pw_shell, nullptr);
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perror("execl");
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exit(1);
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}
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endpwent();
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if (pid == -1)
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{
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perror("fork");
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break;
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}
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int status;
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waitpid(pid, &status, 0);
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if (tcsetpgrp(0, getpgrp()) == -1)
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perror("tcsetpgrp");
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}
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}
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