* Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>

/* $OpenBSD$ */

/*
* Copyright (c) 2007 Nicholas Marriott <[email protected]>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/utsname.h>

#include <errno.h>
#include <fcntl.h>
#include <langinfo.h>
#include <locale.h>
#include <pwd.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "tmux.h"

struct options *global_options; /* server options */
struct options *global_s_options; /* session options */
struct options *global_w_options; /* window options */
struct environ *global_environ;

struct timeval start_time;
const char *socket_path;
int ptm_fd = -1;
const char *shell_command;

static __dead void usage(void);
static char *make_label(const char *, char **);

static int areshell(const char *);
static const char *getshell(void);

static __dead void
usage(void)
{
fprintf(stderr,
"usage: %s [-2CDlNuVv] [-c shell-command] [-f file] [-L socket-name]\n"
" [-S socket-path] [-T features] [command [flags]]\n",
getprogname());
exit(1);
}

static const char *
getshell(void)
{
struct passwd *pw;
const char *shell;

shell = getenv("SHELL");
if (checkshell(shell))
return (shell);

pw = getpwuid(getuid());
if (pw != NULL && checkshell(pw->pw_shell))
return (pw->pw_shell);

return (_PATH_BSHELL);
}

int
checkshell(const char *shell)
{
if (shell == NULL || *shell != '/')
return (0);
if (areshell(shell))
return (0);
if (access(shell, X_OK) != 0)
return (0);
return (1);
}

static int
areshell(const char *shell)
{
const char *progname, *ptr;

if ((ptr = strrchr(shell, '/')) != NULL)
ptr++;
else
ptr = shell;
progname = getprogname();
if (*progname == '-')
progname++;
if (strcmp(ptr, progname) == 0)
return (1);
return (0);
}

static char *
expand_path(const char *path, const char *home)
{
char *expanded, *name;
const char *end;
struct environ_entry *value;

if (strncmp(path, "~/", 2) == 0) {
if (home == NULL)
return (NULL);
xasprintf(&expanded, "%s%s", home, path + 1);
return (expanded);
}

if (*path == '$') {
end = strchr(path, '/');
if (end == NULL)
name = xstrdup(path + 1);
else
name = xstrndup(path + 1, end - path - 1);
value = environ_find(global_environ, name);
free(name);
if (value == NULL)
return (NULL);
if (end == NULL)
end = "";
xasprintf(&expanded, "%s%s", value->value, end);
return (expanded);
}

return (xstrdup(path));
}

static void
expand_paths(const char *s, char ***paths, u_int *n, int ignore_errors)
{
const char *home = find_home();
char *copy, *next, *tmp, resolved[PATH_MAX], *expanded;
char *path;
u_int i;

*paths = NULL;
*n = 0;

copy = tmp = xstrdup(s);
while ((next = strsep(&tmp, ":")) != NULL) {
expanded = expand_path(next, home);
if (expanded == NULL) {
log_debug("%s: invalid path: %s", __func__, next);
continue;
}
if (realpath(expanded, resolved) == NULL) {
log_debug("%s: realpath(\"%s\") failed: %s", __func__,
expanded, strerror(errno));
if (ignore_errors) {
free(expanded);
continue;
}
path = expanded;
} else {
path = xstrdup(resolved);
free(expanded);
}
for (i = 0; i < *n; i++) {
if (strcmp(path, (*paths)[i]) == 0)
break;
}
if (i != *n) {
log_debug("%s: duplicate path: %s", __func__, path);
free(path);
continue;
}
*paths = xreallocarray(*paths, (*n) + 1, sizeof *paths);
(*paths)[(*n)++] = path;
}
free(copy);
}

static char *
make_label(const char *label, char **cause)
{
char **paths, *path, *base;
u_int i, n;
struct stat sb;
uid_t uid;

*cause = NULL;
if (label == NULL)
label = "default";
uid = getuid();

expand_paths(TMUX_SOCK, &paths, &n, 1);
if (n == 0) {
xasprintf(cause, "no suitable socket path");
return (NULL);
}
path = paths[0]; /* can only have one socket! */
for (i = 1; i < n; i++)
free(paths[i]);
free(paths);

xasprintf(&base, "%s/tmux-%ld", path, (long)uid);
free(path);
if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST) {
xasprintf(cause, "couldn't create directory %s (%s)", base,
strerror(errno));
goto fail;
}
if (lstat(base, &sb) != 0) {
xasprintf(cause, "couldn't read directory %s (%s)", base,
strerror(errno));
goto fail;
}
if (!S_ISDIR(sb.st_mode)) {
xasprintf(cause, "%s is not a directory", base);
goto fail;
}
if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) {
xasprintf(cause, "directory %s has unsafe permissions", base);
goto fail;
}
xasprintf(&path, "%s/%s", base, label);
free(base);
return (path);

fail:
free(base);
return (NULL);
}

char *
shell_argv0(const char *shell, int is_login)
{
const char *slash, *name;
char *argv0;

slash = strrchr(shell, '/');
if (slash != NULL && slash[1] != '\0')
name = slash + 1;
else
name = shell;
if (is_login)
xasprintf(&argv0, "-%s", name);
else
xasprintf(&argv0, "%s", name);
return (argv0);
}

void
setblocking(int fd, int state)
{
int mode;

if ((mode = fcntl(fd, F_GETFL)) != -1) {
if (!state)
mode |= O_NONBLOCK;
else
mode &= ~O_NONBLOCK;
fcntl(fd, F_SETFL, mode);
}
}

uint64_t
get_timer(void)
{
struct timespec ts;

/*
* We want a timestamp in milliseconds suitable for time measurement,
* so prefer the monotonic clock.
*/
if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0)
clock_gettime(CLOCK_REALTIME, &ts);
return ((ts.tv_sec * 1000ULL) + (ts.tv_nsec / 1000000ULL));
}

const char *
sig2name(int signo)
{
static char s[11];

#ifdef HAVE_SYS_SIGNAME
if (signo > 0 && signo < NSIG)
return (sys_signame[signo]);
#endif
xsnprintf(s, sizeof s, "%d", signo);
return (s);
}

const char *
find_cwd(void)
{
char resolved1[PATH_MAX], resolved2[PATH_MAX];
static char cwd[PATH_MAX];
const char *pwd;

if (getcwd(cwd, sizeof cwd) == NULL)
return (NULL);
if ((pwd = getenv("PWD")) == NULL || *pwd == '\0')
return (cwd);

/*
* We want to use PWD so that symbolic links are maintained,
* but only if it matches the actual working directory.
*/
if (realpath(pwd, resolved1) == NULL)
return (cwd);
if (realpath(cwd, resolved2) == NULL)
return (cwd);
if (strcmp(resolved1, resolved2) != 0)
return (cwd);
return (pwd);
}

const char *
find_home(void)
{
struct passwd *pw;
static const char *home;

if (home != NULL)
return (home);

home = getenv("HOME");
if (home == NULL || *home == '\0') {
pw = getpwuid(getuid());
if (pw != NULL)
home = pw->pw_dir;
else
home = NULL;
}

return (home);
}

const char *
getversion(void)
{
return (TMUX_VERSION);
}

int
main(int argc, char **argv)
{
char *path = NULL, *label = NULL;
char *cause, **var;
const char *s, *cwd;
int opt, keys, feat = 0, fflag = 0;
uint64_t flags = 0;
const struct options_table_entry *oe;
u_int i;

if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL &&
setlocale(LC_CTYPE, "C.UTF-8") == NULL) {
if (setlocale(LC_CTYPE, "") == NULL)
errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
s = nl_langinfo(CODESET);
if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0)
errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
}

setlocale(LC_TIME, "");
tzset();

if (**argv == '-')
flags = CLIENT_LOGIN;

global_environ = environ_create();
for (var = environ; *var != NULL; var++)
environ_put(global_environ, *var, 0);
if ((cwd = find_cwd()) != NULL)
environ_set(global_environ, "PWD", 0, "%s", cwd);
expand_paths(TMUX_CONF, &cfg_files, &cfg_nfiles, 1);

while ((opt = getopt(argc, argv, "2c:CDdf:lL:NqS:T:uUvV")) != -1) {
switch (opt) {
case '2':
tty_add_features(&feat, "256", ":,");
break;
case 'c':
shell_command = optarg;
break;
case 'D':
flags |= CLIENT_NOFORK;
break;
case 'C':
if (flags & CLIENT_CONTROL)
flags |= CLIENT_CONTROLCONTROL;
else
flags |= CLIENT_CONTROL;
break;
case 'f':
if (!fflag) {
fflag = 1;
for (i = 0; i < cfg_nfiles; i++)
free(cfg_files[i]);
cfg_nfiles = 0;
}
cfg_files = xreallocarray(cfg_files, cfg_nfiles + 1,
sizeof *cfg_files);
cfg_files[cfg_nfiles++] = xstrdup(optarg);
cfg_quiet = 0;
break;
case 'V':
printf("tmux %s\n", getversion());
exit(0);
case 'l':
flags |= CLIENT_LOGIN;
break;
case 'L':
free(label);
label = xstrdup(optarg);
break;
case 'N':
flags |= CLIENT_NOSTARTSERVER;
break;
case 'q':
break;
case 'S':
free(path);
path = xstrdup(optarg);
break;
case 'T':
tty_add_features(&feat, optarg, ":,");
break;
case 'u':
flags |= CLIENT_UTF8;
break;
case 'v':
log_add_level();
break;
default:
usage();
}
}
argc -= optind;
argv += optind;

if (shell_command != NULL && argc != 0)
usage();
if ((flags & CLIENT_NOFORK) && argc != 0)
usage();

if ((ptm_fd = getptmfd()) == -1)
err(1, "getptmfd");
if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
"recvfd proc exec tty ps", NULL) != 0)
err(1, "pledge");

/*
* tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
* Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
* UTF-8, it is a safe assumption that either they are using a UTF-8
* terminal, or if not they know that output from UTF-8-capable
* programs may be wrong.
*/
if (getenv("TMUX") != NULL)
flags |= CLIENT_UTF8;
else {
s = getenv("LC_ALL");
if (s == NULL || *s == '\0')
s = getenv("LC_CTYPE");
if (s == NULL || *s == '\0')
s = getenv("LANG");
if (s == NULL || *s == '\0')
s = "";
if (strcasestr(s, "UTF-8") != NULL ||
strcasestr(s, "UTF8") != NULL)
flags |= CLIENT_UTF8;
}

global_options = options_create(NULL);
global_s_options = options_create(NULL);
global_w_options = options_create(NULL);
for (oe = options_table; oe->name != NULL; oe++) {
if (oe->scope & OPTIONS_TABLE_SERVER)
options_default(global_options, oe);
if (oe->scope & OPTIONS_TABLE_SESSION)
options_default(global_s_options, oe);
if (oe->scope & OPTIONS_TABLE_WINDOW)
options_default(global_w_options, oe);
}

/*
* The default shell comes from SHELL or from the user's passwd entry
* if available.
*/
options_set_string(global_s_options, "default-shell", 0, "%s",
getshell());

/* Override keys to vi if VISUAL or EDITOR are set. */
if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
options_set_string(global_options, "editor", 0, "%s", s);
if (strrchr(s, '/') != NULL)
s = strrchr(s, '/') + 1;
if (strstr(s, "vi") != NULL)
keys = MODEKEY_VI;
else
keys = MODEKEY_EMACS;
options_set_number(global_s_options, "status-keys", keys);
options_set_number(global_w_options, "mode-keys", keys);
}

/*
* If socket is specified on the command-line with -S or -L, it is
* used. Otherwise, $TMUX is checked and if that fails "default" is
* used.
*/
if (path == NULL && label == NULL) {
s = getenv("TMUX");
if (s != NULL && *s != '\0' && *s != ',') {
path = xstrdup(s);
path[strcspn(path, ",")] = '\0';
}
}
if (path == NULL) {
if ((path = make_label(label, &cause)) == NULL) {
if (cause != NULL) {
fprintf(stderr, "%s\n", cause);
free(cause);
}
exit(1);
}
flags |= CLIENT_DEFAULTSOCKET;
}
socket_path = path;
free(label);

/* Pass control to the client. */
exit(client_main(osdep_event_init(), argc, argv, flags, feat));
}