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ly/src/login.c

682 lines
11 KiB
C

#include "dragonfail.h"
#include "termbox.h"
#include "inputs.h"
#include "draw.h"
#include "utils.h"
#include "config.h"
#include "login.h"
#include <errno.h>
#include <grp.h>
#include <pwd.h>
#include <security/pam_appl.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <utmp.h>
#include <xcb/xcb.h>
int get_free_display()
{
char xlock[1024];
uint8_t i;
for (i = 0; i < 200; ++i)
{
snprintf(xlock, 1024, "/tmp/.X%d-lock", i);
if (access(xlock, F_OK) == -1)
{
break;
}
}
return i;
}
void reset_terminal(struct passwd* pwd)
{
pid_t pid = fork();
if (pid == 0)
{
execl(pwd->pw_shell, pwd->pw_shell, "-c", config.term_reset_cmd, NULL);
exit(EXIT_SUCCESS);
}
int status;
waitpid(pid, &status, 0);
}
int login_conv(
int num_msg,
const struct pam_message** msg,
struct pam_response** resp,
void* appdata_ptr)
{
*resp = calloc(num_msg, sizeof (struct pam_response));
if (*resp == NULL)
{
return PAM_BUF_ERR;
}
char* username;
char* password;
int ok = PAM_SUCCESS;
int i;
for (i = 0; i < num_msg; ++i)
{
switch (msg[i]->msg_style)
{
case PAM_PROMPT_ECHO_ON:
{
username = ((char**) appdata_ptr)[0];
(*resp)[i].resp = strdup(username);
break;
}
case PAM_PROMPT_ECHO_OFF:
{
password = ((char**) appdata_ptr)[1];
(*resp)[i].resp = strdup(password);
break;
}
case PAM_ERROR_MSG:
{
ok = PAM_CONV_ERR;
break;
}
}
if (ok != PAM_SUCCESS)
{
break;
}
}
if (ok != PAM_SUCCESS)
{
for (i = 0; i < num_msg; ++i)
{
if ((*resp)[i].resp == NULL)
{
continue;
}
free((*resp)[i].resp);
(*resp)[i].resp = NULL;
}
free(*resp);
*resp = NULL;
}
return ok;
}
void pam_diagnose(int error, struct term_buf* buf)
{
switch (error)
{
case PAM_ACCT_EXPIRED:
{
buf->info_line = lang.err_pam_acct_expired;
break;
}
case PAM_AUTH_ERR:
{
buf->info_line = lang.err_pam_auth;
break;
}
case PAM_AUTHINFO_UNAVAIL:
{
buf->info_line = lang.err_pam_authinfo_unavail;
break;
}
case PAM_BUF_ERR:
{
buf->info_line = lang.err_pam_buf;
break;
}
case PAM_CRED_ERR:
{
buf->info_line = lang.err_pam_cred_err;
break;
}
case PAM_CRED_EXPIRED:
{
buf->info_line = lang.err_pam_cred_expired;
break;
}
case PAM_CRED_INSUFFICIENT:
{
buf->info_line = lang.err_pam_cred_insufficient;
break;
}
case PAM_CRED_UNAVAIL:
{
buf->info_line = lang.err_pam_cred_unavail;
break;
}
case PAM_MAXTRIES:
{
buf->info_line = lang.err_pam_maxtries;
break;
}
case PAM_NEW_AUTHTOK_REQD:
{
buf->info_line = lang.err_pam_authok_reqd;
break;
}
case PAM_PERM_DENIED:
{
buf->info_line = lang.err_pam_perm_denied;
break;
}
case PAM_SESSION_ERR:
{
buf->info_line = lang.err_pam_session;
break;
}
case PAM_SYSTEM_ERR:
{
buf->info_line = lang.err_pam_sys;
break;
}
case PAM_USER_UNKNOWN:
{
buf->info_line = lang.err_pam_user_unknown;
break;
}
case PAM_ABORT:
default:
{
buf->info_line = lang.err_pam_abort;
break;
}
}
dgn_throw(DGN_PAM);
}
void env_init(struct passwd* pwd)
{
extern char** environ;
char* term = getenv("TERM");
char* lang = getenv("LANG");
// clean env
environ[0] = NULL;
if (term != NULL)
{
setenv("TERM", term, 1);
}
else
{
setenv("TERM", "linux", 1);
}
setenv("HOME", pwd->pw_dir, 1);
setenv("PWD", pwd->pw_dir, 1);
setenv("SHELL", pwd->pw_shell, 1);
setenv("USER", pwd->pw_name, 1);
setenv("LOGNAME", pwd->pw_name, 1);
setenv("LANG", lang, 1);
// Set PATH if specified in the configuration
if (strlen(config.path))
{
int ok = setenv("PATH", config.path, 1);
if (ok != 0)
{
dgn_throw(DGN_PATH);
}
}
}
void env_xdg(const char* tty_id, const enum display_server display_server)
{
char user[15];
snprintf(user, 15, "/run/user/%d", getuid());
setenv("XDG_RUNTIME_DIR", user, 0);
setenv("XDG_SESSION_CLASS", "user", 0);
setenv("XDG_SEAT", "seat0", 0);
setenv("XDG_VTNR", tty_id, 0);
switch (display_server)
{
case DS_WAYLAND:
{
setenv("XDG_SESSION_TYPE", "wayland", 1);
break;
}
case DS_SHELL:
{
setenv("XDG_SESSION_TYPE", "tty", 0);
break;
}
case DS_XINITRC:
case DS_XORG:
{
setenv("XDG_SESSION_TYPE", "x11", 0);
break;
}
}
}
void add_utmp_entry(
struct utmp *entry,
char *username,
pid_t display_pid
) {
entry->ut_type = USER_PROCESS;
entry->ut_pid = display_pid;
strcpy(entry->ut_line, ttyname(STDIN_FILENO) + strlen("/dev/"));
/* only correct for ptys named /dev/tty[pqr][0-9a-z] */
strcpy(entry->ut_id, ttyname(STDIN_FILENO) + strlen("/dev/tty"));
time((long int *) &entry->ut_time);
strncpy(entry->ut_user, username, UT_NAMESIZE);
memset(entry->ut_host, 0, UT_HOSTSIZE);
entry->ut_addr = 0;
setutent();
pututline(entry);
}
void remove_utmp_entry(struct utmp *entry) {
entry->ut_type = DEAD_PROCESS;
memset(entry->ut_line, 0, UT_LINESIZE);
entry->ut_time = 0;
memset(entry->ut_user, 0, UT_NAMESIZE);
setutent();
pututline(entry);
endutent();
}
void xauth(const char* display_name, const char* shell, const char* dir)
{
char xauthority[256];
snprintf(xauthority, 256, "%s/%s", dir, ".lyxauth");
setenv("XAUTHORITY", xauthority, 1);
setenv("DISPLAY", display_name, 1);
FILE* fp = fopen(xauthority, "ab+");
if (fp != NULL)
{
fclose(fp);
}
pid_t pid = fork();
if (pid == 0)
{
char cmd[1024];
snprintf(
cmd,
1024,
"%s add %s . `%s`",
config.xauth_cmd,
display_name,
config.mcookie_cmd);
execl(shell, shell, "-c", cmd, NULL);
exit(EXIT_SUCCESS);
}
int status;
waitpid(pid, &status, 0);
}
void xorg(
struct passwd* pwd,
const char* vt,
const char* desktop_cmd)
{
// generate xauthority file
const char* xauth_dir = getenv("XDG_CONFIG_HOME");
if ((xauth_dir == NULL) || (*xauth_dir == '\0'))
{
xauth_dir = pwd->pw_dir;
}
char display_name[4];
snprintf(display_name, 3, ":%d", get_free_display());
xauth(display_name, pwd->pw_shell, xauth_dir);
// start xorg
pid_t pid = fork();
if (pid == 0)
{
char x_cmd[1024];
snprintf(
x_cmd,
1024,
"%s %s %s",
config.x_cmd,
display_name,
vt);
execl(pwd->pw_shell, pwd->pw_shell, "-c", x_cmd, NULL);
exit(EXIT_SUCCESS);
}
int ok;
xcb_connection_t* xcb;
do
{
xcb = xcb_connect(NULL, NULL);
ok = xcb_connection_has_error(xcb);
kill(pid, 0);
}
while((ok != 0) && (errno != ESRCH));
if (ok != 0)
{
return;
}
pid_t xorg_pid = fork();
if (xorg_pid == 0)
{
char de_cmd[1024];
snprintf(
de_cmd,
1024,
"%s %s",
config.x_cmd_setup,
desktop_cmd);
execl(pwd->pw_shell, pwd->pw_shell, "-c", de_cmd, NULL);
exit(EXIT_SUCCESS);
}
int status;
waitpid(xorg_pid, &status, 0);
xcb_disconnect(xcb);
kill(pid, 0);
if (errno != ESRCH)
{
kill(pid, SIGTERM);
waitpid(pid, &status, 0);
}
}
void wayland(
struct passwd* pwd,
const char* desktop_cmd)
{
char cmd[1024];
snprintf(cmd, 1024, "%s %s", config.wayland_cmd, desktop_cmd);
execl(pwd->pw_shell, pwd->pw_shell, "-c", cmd, NULL);
}
void shell(struct passwd* pwd)
{
const char* pos = strrchr(pwd->pw_shell, '/');
char args[1024];
args[0] = '-';
if (pos != NULL)
{
pos = pos + 1;
}
else
{
pos = pwd->pw_shell;
}
strncpy(args + 1, pos, 1023);
execl(pwd->pw_shell, args, NULL);
}
// pam_do performs the pam action specified in pam_action
// on pam_action fail, call diagnose and end pam session
int pam_do(
int (pam_action)(struct pam_handle *, int),
struct pam_handle *handle,
int flags,
struct term_buf *buf)
{
int status = pam_action(handle, flags);
if (status != PAM_SUCCESS) {
pam_diagnose(status, buf);
pam_end(handle, status);
}
return status;
}
void auth(
struct desktop* desktop,
struct text* login,
struct text* password,
struct term_buf* buf)
{
int ok;
// open pam session
const char* creds[2] = {login->text, password->text};
struct pam_conv conv = {login_conv, creds};
struct pam_handle* handle;
ok = pam_start(config.service_name, NULL, &conv, &handle);
if (ok != PAM_SUCCESS)
{
pam_diagnose(ok, buf);
pam_end(handle, ok);
return;
}
ok = pam_do(pam_authenticate, handle, 0, buf);
if (ok != PAM_SUCCESS)
{
return;
}
ok = pam_do(pam_acct_mgmt, handle, 0, buf);
if (ok != PAM_SUCCESS)
{
return;
}
ok = pam_do(pam_setcred, handle, PAM_ESTABLISH_CRED, buf);
if (ok != PAM_SUCCESS)
{
return;
}
ok = pam_do(pam_open_session, handle, 0, buf);
if (ok != PAM_SUCCESS)
{
return;
}
// clear the credentials
input_text_clear(password);
// get passwd structure
struct passwd* pwd = getpwnam(login->text);
endpwent();
if (pwd == NULL)
{
dgn_throw(DGN_PWNAM);
pam_end(handle, ok);
return;
}
// set user shell
if (pwd->pw_shell[0] == '\0')
{
setusershell();
char* shell = getusershell();
if (shell != NULL)
{
strcpy(pwd->pw_shell, shell);
}
endusershell();
}
// restore regular terminal mode
tb_clear();
tb_present();
tb_shutdown();
// start desktop environment
pid_t pid = fork();
if (pid == 0)
{
// set user info
ok = initgroups(pwd->pw_name, pwd->pw_gid);
if (ok != 0)
{
dgn_throw(DGN_USER_INIT);
exit(EXIT_FAILURE);
}
ok = setgid(pwd->pw_gid);
if (ok != 0)
{
dgn_throw(DGN_USER_GID);
exit(EXIT_FAILURE);
}
ok = setuid(pwd->pw_uid);
if (ok != 0)
{
dgn_throw(DGN_USER_UID);
exit(EXIT_FAILURE);
}
// get a display
char tty_id [3];
char vt[5];
snprintf(tty_id, 3, "%d", config.tty);
snprintf(vt, 5, "vt%d", config.tty);
// set env
env_init(pwd);
if (dgn_catch())
{
exit(EXIT_FAILURE);
}
// add pam variables
char** env = pam_getenvlist(handle);
for (uint16_t i = 0; env && env[i]; ++i)
{
putenv(env[i]);
}
// add xdg variables
env_xdg(tty_id, desktop->display_server[desktop->cur]);
// execute
int ok = chdir(pwd->pw_dir);
if (ok != 0)
{
dgn_throw(DGN_CHDIR);
exit(EXIT_FAILURE);
}
reset_terminal(pwd);
switch (desktop->display_server[desktop->cur])
{
case DS_WAYLAND:
{
wayland(pwd, desktop->cmd[desktop->cur]);
break;
}
case DS_SHELL:
{
shell(pwd);
break;
}
case DS_XINITRC:
case DS_XORG:
{
xorg(pwd, vt, desktop->cmd[desktop->cur]);
break;
}
}
exit(EXIT_SUCCESS);
}
// add utmp audit
struct utmp entry;
add_utmp_entry(&entry, pwd->pw_name, pid);
// wait for the session to stop
int status;
waitpid(pid, &status, 0);
remove_utmp_entry(&entry);
reset_terminal(pwd);
// reinit termbox
tb_init();
tb_select_output_mode(TB_OUTPUT_NORMAL);
// reload the desktop environment list on logout
input_desktop_free(desktop);
input_desktop(desktop);
desktop_load(desktop);
// close pam session
ok = pam_do(pam_close_session, handle, 0, buf);
if (ok != PAM_SUCCESS)
{
return;
}
ok = pam_do(pam_setcred, handle, PAM_DELETE_CRED, buf);
if (ok != PAM_SUCCESS)
{
return;
}
ok = pam_end(handle, 0);
if (ok != PAM_SUCCESS)
{
pam_diagnose(ok, buf);
}
}