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/* backend.c - twoftpd back-end startup code
* Copyright (C) 2008 Bruce Guenter <bruce@untroubled.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <sys/types.h>
#include <grp.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <systime.h>
#include <unistd.h>
#include <sysdeps.h>
#include <path/path.h>
#include "twoftpd.h"
#include "backend.h"
uid_t uid;
gid_t gid;
const char* home;
const char* user;
unsigned user_len;
const char* group;
unsigned group_len;
time_t now;
int lockhome;
int nodotfiles;
int bind_port_fd = -1;
unsigned connect_timeout = 0;
int handle_pass(void)
{
return respond(230, 1, "Access has already been granted.");
}
static int load_tables(void)
{
/* Load some initial values that cannot be loaded once the chroot is done. */
/* A call to localtime should load and cache the timezone setting. */
now = time(0);
localtime(&now);
return 1;
}
static int parse_gids(const char* gids)
{
gid_t groups[NGROUPS_MAX];
int count;
const char* ptr;
ptr = gids;
count = 0;
while (*ptr != 0 && count < NGROUPS_MAX) {
groups[count] = strtou(ptr, &ptr);
if (*ptr != 0 && *ptr != ',') return 0;
while (*ptr == ',') ++ptr;
++count;
}
if (setgroups(count, groups) == -1) return 0;
return 1;
}
#define FAIL(MSG) do{ respond(421, 1, MSG); return 0; }while(0)
int startup(int argc, char* argv[])
{
const char* tmp;
const char* end;
const char* cwdstr;
char* ptr;
unsigned long session_timeout;
unsigned startup_code;
if ((tmp = getenv("TCPLOCALIP")) == 0) FAIL("Missing $TCPLOCALIP.");
if (!parse_localip(tmp)) FAIL("Could not parse $TCPLOCALIP.");
if ((tmp = getenv("TCPREMOTEIP")) == 0) FAIL("Missing $TCPREMOTEIP.");
if (!parse_remoteip(tmp)) FAIL("Could not parse $TCPREMOTEIP.");
if ((tmp = getenv("UID")) == 0) FAIL("Missing $UID.");
if (!(uid = strtou(tmp, &end)) || *end) FAIL("Invalid $UID.");
if ((tmp = getenv("GID")) == 0) FAIL("Missing $GID.");
if (!(gid = strtou(tmp, &end)) || *end) FAIL("Invalid $GID.");
if ((home = getenv("HOME")) == 0) FAIL("Missing $HOME.");
if ((tmp = getenv("GIDS")) != 0 && !parse_gids(tmp))
FAIL("Could not parse or set supplementary group IDs.");
/* Strip off trailing slashes in $HOME */
ptr = (char*)home + strlen(home)-1;
while (ptr > home && *ptr == '/') *ptr-- = 0;
if ((user = getenv("USER")) == 0) FAIL("Missing $USER.");
if ((group = getenv("GROUP")) == 0) group = "mygroup";
if (chdir(home)) FAIL("Could not chdir to $HOME.");
if (!load_tables()) FAIL("Loading startup tables failed.");
if (getenv("CHROOT") != 0) {
cwdstr = "/";
if (chroot(".")) FAIL("Could not chroot.");
}
else if (getenv("SOFTCHROOT") != 0) {
cwdstr = "/";
}
else {
cwdstr = home;
if (chdir("/")) FAIL("Could not chdir to '/'.");
}
if (!str_copys(&cwd, cwdstr)) FAIL("Could not set CWD string");
if (setgid(gid)) FAIL("Could not set GID.");
if (setuid(uid)) FAIL("Could not set UID.");
if ((user_len = strlen(user)) > MAX_NAME_LEN) {
user_len = MAX_NAME_LEN;
((char*)user)[MAX_NAME_LEN] = 0;
}
if ((group_len = strlen(group)) > MAX_NAME_LEN) {
group_len = MAX_NAME_LEN;
((char*)group)[MAX_NAME_LEN] = 0;
}
lockhome = (getenv("LOCKHOME") != 0);
nodotfiles = (getenv("NODOTFILES") != 0);
list_options = (nodotfiles ? 0 : PATH_MATCH_DOTFILES);
session_timeout = 0;
if ((tmp = getenv("SESSION_TIMEOUT")) != 0)
session_timeout = strtou(tmp, &tmp);
alarm(session_timeout);
connect_timeout = timeout;
if ((tmp = getenv("CONNECT_TIMEOUT")) != 0)
connect_timeout = strtou(tmp, &tmp);
if ((tmp = getenv("TWOFTPD_BIND_PORT_FD")) != 0) {
if ((bind_port_fd = strtou(tmp, &end)) == 0 || *end != 0)
FAIL("Invalid $TWOFTPD_BIND_PORT_FD");
}
else
bind_port_fd = -1;
startup_code = (getenv("AUTHENTICATED") != 0) ? 230 : 220;
if ((tmp = getenv("BANNER")) != 0) show_banner(startup_code, tmp);
message_file = getenv("MESSAGEFILE");
show_message_file(startup_code);
return respond(startup_code, 1, "Ready to transfer files.");
(void)argc;
(void)argv;
}
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