/*
* The socket based protocol for setting up a connection with rsyncd.
*
* Copyright (C) 1998-2001 Andrew Tridgell <tridge@samba.org>
* Copyright (C) 2001-2002 Martin Pool <mbp@samba.org>
* Copyright (C) 2002-2020 Wayne Davison
*
* 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 3 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, visit the http://fsf.org website.
*/
#include "rsync.h"
#include "itypes.h"
#include "ifuncs.h"
extern int quiet;
extern int dry_run;
extern int output_motd;
extern int list_only;
extern int am_sender;
extern int am_server;
extern int am_daemon;
extern int am_root;
extern int msgs2stderr;
extern int rsync_port;
extern int protect_args;
extern int ignore_errors;
extern int preserve_xattrs;
extern int kluge_around_eof;
extern int munge_symlinks;
extern int open_noatime;
extern int sanitize_paths;
extern int numeric_ids;
extern int filesfrom_fd;
extern int remote_protocol;
extern int protocol_version;
extern int always_checksum;
extern int checksum_files;
extern int io_timeout;
extern int no_detach;
extern int write_batch;
extern int default_af_hint;
extern int logfile_format_has_i;
extern int logfile_format_has_o_or_i;
extern char *bind_address;
extern char *config_file;
extern char *link_by_hash_dir;
extern char *logfile_format;
extern char *files_from;
extern char *tmpdir;
extern char *early_input_file;
extern struct chmod_mode_struct *chmod_modes;
extern filter_rule_list daemon_filter_list;
#ifdef ICONV_OPTION
extern char *iconv_opt;
extern iconv_t ic_send, ic_recv;
#endif
extern uid_t our_uid;
extern gid_t our_gid;
char *auth_user;
int read_only = 0;
int module_id = -1;
int pid_file_fd = -1;
int early_input_len = 0;
char *early_input = NULL;
pid_t namecvt_pid = 0;
struct chmod_mode_struct *daemon_chmod_modes;
#define EARLY_INPUT_CMD "#early_input="
#define EARLY_INPUT_CMDLEN (sizeof EARLY_INPUT_CMD - 1)
/* module_dirlen is the length of the module_dir string when in daemon
* mode and module_dir is not "/"; otherwise 0. (Note that a chroot-
* enabled module can have a non-"/" module_dir these days.) */
char *module_dir = NULL;
unsigned int module_dirlen = 0;
char *full_module_path;
static int rl_nulls = 0;
static int namecvt_fd_req = -1, namecvt_fd_ans = -1;
#ifdef HAVE_SIGACTION
static struct sigaction sigact;
#endif
static item_list gid_list = EMPTY_ITEM_LIST;
/* Used when "reverse lookup" is off. */
const char undetermined_hostname[] = "UNDETERMINED";
/**
* Run a client connected to an rsyncd. The alternative to this
* function for remote-shell connections is do_cmd().
*
* After negotiating which module to use and reading the server's
* motd, this hands over to client_run(). Telling the server the
* module will cause it to chroot/setuid/etc.
*
* Instead of doing a transfer, the client may at this stage instead
* get a listing of remote modules and exit.
*
* @return -1 for error in startup, or the result of client_run().
* Either way, it eventually gets passed to exit_cleanup().
**/
int start_socket_client(char *host, int remote_argc, char *remote_argv[],
int argc, char *argv[])
{
int fd, ret;
char *p, *user = NULL;
/* This is redundant with code in start_inband_exchange(), but this
* short-circuits a problem in the client before we open a socket,
* and the extra check won't hurt. */
if (**remote_argv == '/') {
rprintf(FERROR,
"ERROR: The remote path must start with a module name not a /\n");
return -1;
}
if ((p = strrchr(host, '@')) != NULL) {
user = host;
host = p+1;
*p = '\0';
}
fd = open_socket_out_wrapped(host, rsync_port, bind_address, default_af_hint);
if (fd == -1)
exit_cleanup(RERR_SOCKETIO);
#ifdef ICONV_CONST
setup_iconv();
#endif
ret = start_inband_exchange(fd, fd, user, host, remote_argc, remote_argv);
return ret ? ret : client_run(fd, fd, -1, argc, argv);
}
static int exchange_protocols(int f_in, int f_out, char *buf, size_t bufsiz, int am_client)
{
int remote_sub = -1;
#if SUBPROTOCOL_VERSION != 0
int our_sub = protocol_version < PROTOCOL_VERSION ? 0 : SUBPROTOCOL_VERSION;
#else
int our_sub = 0;
#endif
io_printf(f_out, "@RSYNCD: %d.%d\n", protocol_version, our_sub);
if (!am_client) {
char *motd = lp_motd_file();
if (motd && *motd) {
FILE *f = fopen(motd, "r");
while (f && !feof(f)) {
int len = fread(buf, 1, bufsiz - 1, f);
if (len > 0)
write_buf(f_out, buf, len);
}
if (f)
fclose(f);
write_sbuf(f_out, "\n");
}
}
/* This strips the \n. */
if (!read_line_old(f_in, buf, bufsiz, 0)) {
if (am_client)
rprintf(FERROR, "rsync: did not see server greeting\n");
return -1;
}
if (sscanf(buf, "@RSYNCD: %d.%d", &remote_protocol, &remote_sub) < 1) {
if (am_client)
rprintf(FERROR, "rsync: server sent \"%s\" rather than greeting\n", buf);
else
io_printf(f_out, "@ERROR: protocol startup error\n");
return -1;
}
if (remote_sub < 0) {
if (remote_protocol == 30) {
if (am_client)
rprintf(FERROR, "rsync: server is speaking an incompatible beta of protocol 30\n");
else
io_printf(f_out, "@ERROR: your client is speaking an incompatible beta of protocol 30\n");
return -1;
}
remote_sub = 0;
}
if (protocol_version > remote_protocol) {
protocol_version = remote_protocol;
if (remote_sub)
protocol_version--;
} else if (protocol_version == remote_protocol) {
if (remote_sub != our_sub)
protocol_version--;
}
#if SUBPROTOCOL_VERSION != 0
else if (protocol_version < remote_protocol) {
if (our_sub)
protocol_version--;
}
#endif
if (protocol_version >= 30)
rl_nulls = 1;
return 0;
}
int start_inband_exchange(int f_in, int f_out, const char *user, const char *host, int argc, char *argv[])
{
int i, modlen;
char line[BIGPATHBUFLEN];
char *sargs[MAX_ARGS];
int sargc = 0;
char *p, *modname;
assert(argc > 0 && *argv != NULL);
if (**argv == '/') {
rprintf(FERROR,
"ERROR: The remote path must start with a module name\n");
return -1;
}
if (!(p = strchr(*argv, '/')))
modlen = strlen(*argv);
else
modlen = p - *argv;
modname = new_array(char, modlen+1+1); /* room for '/' & '\0' */
strlcpy(modname, *argv, modlen + 1);
modname[modlen] = '/';
modname[modlen+1] = '\0';
if (!user)
user = getenv("USER");
if (!user)
user = getenv("LOGNAME");
if (exchange_protocols(f_in, f_out, line, sizeof line, 1) < 0)
return -1;
if (early_input_file) {
STRUCT_STAT st;
FILE *f = fopen(early_input_file, "rb");
if (!f || do_fstat(fileno(f), &st) < 0) {
rsyserr(FERROR, errno, "failed to open %s", early_input_file);
return -1;
}
early_input_len = st.st_size;
if (early_input_len > (int)sizeof line) {
rprintf(FERROR, "%s is > %d bytes.\n", early_input_file, (int)sizeof line);
return -1;
}
if (early_input_len > 0) {
io_printf(f_out, EARLY_INPUT_CMD "%d\n", early_input_len);
while (early_input_len > 0) {
int len;
if (feof(f)) {
rprintf(FERROR, "Early EOF in %s\n", early_input_file);
return -1;
}
len = fread(line, 1, early_input_len, f);
if (len > 0) {
write_buf(f_out, line, len);
early_input_len -= len;
}
}
}
fclose(f);
}
server_options(sargs, &sargc);
if (sargc >= MAX_ARGS - 2)
goto arg_overflow;
sargs[sargc++] = ".";
while (argc > 0) {
if (sargc >= MAX_ARGS - 1) {
arg_overflow:
rprintf(FERROR, "internal: args[] overflowed in do_cmd()\n");
exit_cleanup(RERR_SYNTAX);
}
if (strncmp(*argv, modname, modlen) == 0
&& argv[0][modlen] == '\0')
sargs[sargc++] = modname; /* we send "modname/" */
else if (**argv == '-') {
if (asprintf(sargs + sargc++, "./%s", *argv) < 0)
out_of_memory("start_inband_exchange");
} else
sargs[sargc++] = *argv;
argv++;
argc--;
}
sargs[sargc] = NULL;
if (DEBUG_GTE(CMD, 1))
print_child_argv("sending daemon args:", sargs);
io_printf(f_out, "%.*s\n", modlen, modname);
/* Old servers may just drop the connection here,
rather than sending a proper EXIT command. Yuck. */
kluge_around_eof = list_only && protocol_version < 25 ? 1 : 0;
while (1) {
if (!read_line_old(f_in, line, sizeof line, 0)) {
rprintf(FERROR, "rsync: didn't get server startup line\n");
return -1;
}
if (strncmp(line,"@RSYNCD: AUTHREQD ",18) == 0) {
auth_client(f_out, user, line+18);
continue;
}
if (strcmp(line, "@RSYNCD: GSS") == 0) {
#ifdef GSSAPI_OPTION
if (auth_gss_client(f_out, host) < 0)
return -1;
continue;
#else
rprintf(FERROR, "GSSAPI is not supported\n");
return -1;
#endif
}
if (strcmp(line,"@RSYNCD: OK") == 0)
break;
if (strcmp(line,"@RSYNCD: EXIT") == 0) {
/* This is sent by recent versions of the
* server to terminate the listing of modules.
* We don't want to go on and transfer
* anything; just exit. */
exit(0);
}
if (strncmp(line, "@ERROR", 6) == 0) {
rprintf(FERROR, "%s\n", line);
/* This is always fatal; the server will now
* close the socket. */
return -1;
}
/* This might be a MOTD line or a module listing, but there is
* no way to differentiate it. The manpage mentions this. */
if (output_motd)
rprintf(FINFO, "%s\n", line);
}
kluge_around_eof = 0;
if (rl_nulls) {
for (i = 0; i < sargc; i++) {
if (!sargs[i]) /* stop at --protect-args NULL */
break;
write_sbuf(f_out, sargs[i]);
write_byte(f_out, 0);
}
write_byte(f_out, 0);
} else {
for (i = 0; i < sargc; i++)
io_printf(f_out, "%s\n", sargs[i]);
write_sbuf(f_out, "\n");
}
if (protect_args)
send_protected_args(f_out, sargs);
if (protocol_version < 23) {
if (protocol_version == 22 || !am_sender)
io_start_multiplex_in(f_in);
}
free(modname);
return 0;
}
#ifdef HAVE_PUTENV
static int read_arg_from_pipe(int fd, char *buf, int limit)
{
char *bp = buf, *eob = buf + limit - 1;
while (1) {
int got = read(fd, bp, 1);
if (got != 1) {
if (got < 0 && errno == EINTR)
continue;
return -1;
}
if (*bp == '\0')
break;
if (bp < eob)
bp++;
}
*bp = '\0';
return bp - buf;
}
#endif
static void set_env_str(const char *var, const char *str)
{
#ifdef HAVE_PUTENV
char *mem;
if (asprintf(&mem, "%s=%s", var, str) < 0)
out_of_memory("set_env_str");
putenv(mem);
#endif
}
#ifdef HAVE_PUTENV
void set_env_num(const char *var, long num)
{
char *mem;
if (asprintf(&mem, "%s=%ld", var, num) < 0)
out_of_memory("set_env_num");
putenv(mem);
}
#endif
/* Used for "early exec", "pre-xfer exec", and the "name converter" script. */
static pid_t start_pre_exec(const char *cmd, int *arg_fd_ptr, int *error_fd_ptr)
{
int arg_fds[2], error_fds[2], arg_fd;
pid_t pid;
if ((error_fd_ptr && pipe(error_fds) < 0) || pipe(arg_fds) < 0 || (pid = fork()) < 0)
return (pid_t)-1;
if (pid == 0) {
char buf[BIGPATHBUFLEN];
int j, len, status;
if (error_fd_ptr) {
close(error_fds[0]);
set_blocking(error_fds[1]);
}
close(arg_fds[1]);
arg_fd = arg_fds[0];
set_blocking(arg_fd);
len = read_arg_from_pipe(arg_fd, buf, BIGPATHBUFLEN);
if (len <= 0)
_exit(1);
set_env_str("RSYNC_REQUEST", buf);
for (j = 0; ; j++) {
char *p;
len = read_arg_from_pipe(arg_fd, buf, BIGPATHBUFLEN);
if (len <= 0) {
if (!len)
break;
_exit(1);
}
if (asprintf(&p, "RSYNC_ARG%d=%s", j, buf) >= 0)
putenv(p);
}
dup2(arg_fd, STDIN_FILENO);
close(arg_fd);
if (error_fd_ptr) {
dup2(error_fds[1], STDOUT_FILENO);
close(error_fds[1]);
}
status = shell_exec(cmd);
if (!WIFEXITED(status))
_exit(1);
_exit(WEXITSTATUS(status));
}
if (error_fd_ptr) {
close(error_fds[1]);
*error_fd_ptr = error_fds[0];
set_blocking(error_fds[0]);
}
close(arg_fds[0]);
arg_fd = *arg_fd_ptr = arg_fds[1];
set_blocking(arg_fd);
return pid;
}
static void write_pre_exec_args(int write_fd, char *request, char **early_argv, char **argv, int exec_type)
{
int j = 0;
if (!request)
request = "(NONE)";
write_buf(write_fd, request, strlen(request)+1);
if (early_argv) {
for ( ; *early_argv; early_argv++)
write_buf(write_fd, *early_argv, strlen(*early_argv)+1);
j = 1; /* Skip arg0 name in argv. */
}
if (argv) {
for ( ; argv[j]; j++)
write_buf(write_fd, argv[j], strlen(argv[j])+1);
}
write_byte(write_fd, 0);
if (exec_type == 1 && early_input_len)
write_buf(write_fd, early_input, early_input_len);
if (exec_type != 2) /* the name converter needs this left open */
close(write_fd);
}
static char *finish_pre_exec(const char *desc, pid_t pid, int read_fd)
{
char buf[BIGPATHBUFLEN], *bp, *cr;
int j, status = -1, msglen = sizeof buf - 1;
if (read_fd >= 0) {
/* Read the stdout from the program. This it is only displayed
* to the user if the script also returns an error status. */
for (bp = buf, cr = buf; msglen > 0; msglen -= j) {
if ((j = read(read_fd, bp, msglen)) <= 0) {
if (j == 0)
break;
if (errno == EINTR)
continue;
break; /* Just ignore the read error for now... */
}
bp[j] = '\0';
while (1) {
if ((cr = strchr(cr, '\r')) == NULL) {
cr = bp + j;
break;
}
if (!cr[1])
break; /* wait for more data before we decide what to do */
if (cr[1] == '\n') {
memmove(cr, cr+1, j - (cr - bp));
j--;
} else
cr++;
}
bp += j;
}
*bp = '\0';
close(read_fd);
} else
*buf = '\0';
if (wait_process(pid, &status, 0) < 0
|| !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
char *e;
if (asprintf(&e, "%s returned failure (%d)%s%s%s\n%s",
desc, status, status < 0 ? ": " : "",
status < 0 ? strerror(errno) : "",
*buf ? ":" : "", buf) < 0)
return "out_of_memory in finish_pre_exec\n";
return e;
}
return NULL;
}
static int path_failure(int f_out, const char *dir, BOOL was_chdir)
{
if (was_chdir)
rsyserr(FLOG, errno, "chdir %s failed", dir);
else
rprintf(FLOG, "normalize_path(%s) failed\n", dir);
io_printf(f_out, "@ERROR: chdir failed\n");
return -1;
}
static int add_a_group(int f_out, const char *gname)
{
gid_t gid, *gid_p;
if (!group_to_gid(gname, &gid, True)) {
rprintf(FLOG, "Invalid gid %s\n", gname);
io_printf(f_out, "@ERROR: invalid gid %s\n", gname);
return -1;
}
gid_p = EXPAND_ITEM_LIST(&gid_list, gid_t, -32);
*gid_p = gid;
return 0;
}
#ifdef HAVE_GETGROUPLIST
static int want_all_groups(int f_out, uid_t uid)
{
const char *err;
if ((err = getallgroups(uid, &gid_list)) != NULL) {
rsyserr(FLOG, errno, "%s", err);
io_printf(f_out, "@ERROR: %s\n", err);
return -1;
}
return 0;
}
#elif defined HAVE_INITGROUPS
static struct passwd *want_all_groups(int f_out, uid_t uid)
{
struct passwd *pw;
gid_t *gid_p;
if ((pw = getpwuid(uid)) == NULL) {
rsyserr(FLOG, errno, "getpwuid failed");
io_printf(f_out, "@ERROR: getpwuid failed\n");
return NULL;
}
/* Start with the default group and initgroups() will add the rest. */
gid_p = EXPAND_ITEM_LIST(&gid_list, gid_t, -32);
*gid_p = pw->pw_gid;
return pw;
}
#endif
static int rsync_module(int f_in, int f_out, int i, const char *addr, const char *host)
{
int argc;
char **argv, **orig_argv, **orig_early_argv, *module_chdir;
char line[BIGPATHBUFLEN];
#if defined HAVE_INITGROUPS && !defined HAVE_GETGROUPLIST
struct passwd *pw = NULL;
#endif
uid_t uid;
int set_uid;
char *p, *err_msg = NULL;
char *name = lp_name(i);
int use_chroot = lp_use_chroot(i);
int ret, pre_exec_arg_fd = -1, pre_exec_error_fd = -1;
int save_munge_symlinks;
pid_t pre_exec_pid = 0;
char *request = NULL;
set_env_str("RSYNC_MODULE_NAME", name);
#ifdef ICONV_OPTION
iconv_opt = lp_charset(i);
if (*iconv_opt)
setup_iconv();
iconv_opt = NULL;
#endif
/* If reverse lookup is disabled globally but enabled for this module,
* we need to do it now before the access check. */
if (host == undetermined_hostname && lp_reverse_lookup(i))
host = client_name(client_addr(f_in));
set_env_str("RSYNC_HOST_NAME", host);
set_env_str("RSYNC_HOST_ADDR", addr);
if (!allow_access(addr, &host, i)) {
rprintf(FLOG, "rsync denied on module %s from %s (%s)\n",
name, host, addr);
if (!lp_list(i))
io_printf(f_out, "@ERROR: Unknown module '%s'\n", name);
else {
io_printf(f_out,
"@ERROR: access denied to %s from %s (%s)\n",
name, host, addr);
}
return -1;
}
if (*lp_link_by_hash_dir(i))
link_by_hash_dir = lp_link_by_hash_dir(i);
if (am_daemon > 0) {
rprintf(FLOG, "rsync allowed access on module %s from %s (%s)\n",
name, host, addr);
}
if (!claim_connection(lp_lock_file(i), lp_max_connections(i))) {
if (errno) {
rsyserr(FLOG, errno, "failed to open lock file %s",
lp_lock_file(i));
io_printf(f_out, "@ERROR: failed to open lock file\n");
} else {
rprintf(FLOG, "max connections (%d) reached\n",
lp_max_connections(i));
io_printf(f_out, "@ERROR: max connections (%d) reached -- try again later\n",
lp_max_connections(i));
}
return -1;
}
read_only = lp_read_only(i); /* may also be overridden by auth_server() */
#ifdef GSSAPI_OPTION
if (lp_use_gssapi(i))
auth_user = auth_gss_server(f_in, f_out, i, host, addr, "@RSYNCD: GSS");
else
#endif
auth_user = auth_server(f_in, f_out, i, host, addr, "@RSYNCD: AUTHREQD ");
if (!auth_user) {
io_printf(f_out, "@ERROR: auth failed on module %s\n", name);
return -1;
}
set_env_str("RSYNC_USER_NAME", auth_user);
module_id = i;
if (lp_transfer_logging(module_id) && !logfile_format)
logfile_format = lp_log_format(module_id);
if (log_format_has(logfile_format, 'i'))
logfile_format_has_i = 1;
if (logfile_format_has_i || log_format_has(logfile_format, 'o'))
logfile_format_has_o_or_i = 1;
uid = MY_UID();
am_root = (uid == ROOT_UID);
p = *lp_uid(module_id) ? lp_uid(module_id) : am_root ? NOBODY_USER : NULL;
if (p) {
if (!user_to_uid(p, &uid, True)) {
rprintf(FLOG, "Invalid uid %s\n", p);
io_printf(f_out, "@ERROR: invalid uid %s\n", p);
return -1;
}
set_uid = 1;
} else
set_uid = 0;
p = *lp_gid(module_id) ? conf_strtok(lp_gid(module_id)) : NULL;
if (p) {
/* The "*" gid must be the first item in the list. */
if (strcmp(p, "*") == 0) {
#ifdef HAVE_GETGROUPLIST
if (want_all_groups(f_out, uid) < 0)
return -1;
#elif defined HAVE_INITGROUPS
if ((pw = want_all_groups(f_out, uid)) == NULL)
return -1;
#else
rprintf(FLOG, "This rsync does not support a gid of \"*\"\n");
io_printf(f_out, "@ERROR: invalid gid setting.\n");
return -1;
#endif
} else if (add_a_group(f_out, p) < 0)
return -1;
while ((p = conf_strtok(NULL)) != NULL) {
#if defined HAVE_INITGROUPS && !defined HAVE_GETGROUPLIST
if (pw) {
rprintf(FLOG, "This rsync cannot add groups after \"*\".\n");
io_printf(f_out, "@ERROR: invalid gid setting.\n");
return -1;
}
#endif
if (add_a_group(f_out, p) < 0)
return -1;
}
} else if (am_root) {
if (add_a_group(f_out, NOBODY_GROUP) < 0)
return -1;
}
module_dir = lp_path(module_id);
if (*module_dir == '\0') {
rprintf(FLOG, "No path specified for module %s\n", name);
io_printf(f_out, "@ERROR: no path setting.\n");
return -1;
}
if (use_chroot) {
if ((p = strstr(module_dir, "/./")) != NULL) {
*p = '\0'; /* Temporary... */
if (!(module_chdir = normalize_path(module_dir, True, NULL)))
return path_failure(f_out, module_dir, False);
*p = '/';
if (!(p = normalize_path(p + 2, True, &module_dirlen)))
return path_failure(f_out, strstr(module_dir, "/./"), False);
if (!(full_module_path = normalize_path(module_dir, False, NULL)))
full_module_path = module_dir;
module_dir = p;
} else {
if (!(module_chdir = normalize_path(module_dir, False, NULL)))
return path_failure(f_out, module_dir, False);
full_module_path = module_chdir;
module_dir = "/";
module_dirlen = 1;
}
} else {
if (!(module_chdir = normalize_path(module_dir, False, &module_dirlen)))
return path_failure(f_out, module_dir, False);
full_module_path = module_dir = module_chdir;
}
set_env_str("RSYNC_MODULE_PATH", full_module_path);
if (module_dirlen == 1) {
module_dirlen = 0;
set_filter_dir("/", 1);
} else
set_filter_dir(module_dir, module_dirlen);
p = lp_filter(module_id);
parse_filter_str(&daemon_filter_list, p, rule_template(FILTRULE_WORD_SPLIT),
XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3);
p = lp_include_from(module_id);
parse_filter_file(&daemon_filter_list, p, rule_template(FILTRULE_INCLUDE),
XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES | XFLG_FATAL_ERRORS);
p = lp_include(module_id);
parse_filter_str(&daemon_filter_list, p,
rule_template(FILTRULE_INCLUDE | FILTRULE_WORD_SPLIT),
XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES);
p = lp_exclude_from(module_id);
parse_filter_file(&daemon_filter_list, p, rule_template(0),
XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES | XFLG_FATAL_ERRORS);
p = lp_exclude(module_id);
parse_filter_str(&daemon_filter_list, p, rule_template(FILTRULE_WORD_SPLIT),
XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES);
log_init(1);
if (*lp_db_config(i)) {
db_read_config(FLOG, lp_db_config(i));
db_lax = lp_db_lax(i);
}
#ifdef HAVE_PUTENV
if ((*lp_early_exec(module_id) || *lp_prexfer_exec(module_id)
|| *lp_postxfer_exec(module_id) || *lp_name_converter(module_id))
&& !getenv("RSYNC_NO_XFER_EXEC")) {
set_env_num("RSYNC_PID", (long)getpid());
/* For post-xfer exec, fork a new process to run the rsync
* daemon while this process waits for the exit status and
* runs the indicated command at that point. */
if (*lp_postxfer_exec(module_id)) {
pid_t pid = fork();
if (pid < 0) {
rsyserr(FLOG, errno, "fork failed");
io_printf(f_out, "@ERROR: fork failed\n");
return -1;
}
if (pid) {
int status;
close(f_in);
if (f_out != f_in)
close(f_out);
if (wait_process(pid, &status, 0) < 0)
status = -1;
set_env_num("RSYNC_RAW_STATUS", status);
if (WIFEXITED(status))
status = WEXITSTATUS(status);
else
status = -1;
set_env_num("RSYNC_EXIT_STATUS", status);
if (shell_exec(lp_postxfer_exec(module_id)) < 0)
status = -1;
_exit(status);
}
}
/* For early exec, fork a child process to run the indicated
* command and wait for it to exit. */
if (*lp_early_exec(module_id)) {
int arg_fd;
pid_t pid = start_pre_exec(lp_early_exec(module_id), &arg_fd, NULL);
if (pid == (pid_t)-1) {
rsyserr(FLOG, errno, "early exec preparation failed");
io_printf(f_out, "@ERROR: early exec preparation failed\n");
return -1;
}
write_pre_exec_args(arg_fd, NULL, NULL, NULL, 1);
if (finish_pre_exec("early exec", pid, -1) != NULL) {
rsyserr(FLOG, errno, "early exec failed");
io_printf(f_out, "@ERROR: early exec failed\n");
return -1;
}
}
/* For pre-xfer exec, fork a child process to run the indicated
* command, though it first waits for the parent process to
* send us the user's request via a pipe. */
if (*lp_prexfer_exec(module_id)) {
pre_exec_pid = start_pre_exec(lp_prexfer_exec(module_id), &pre_exec_arg_fd, &pre_exec_error_fd);
if (pre_exec_pid == (pid_t)-1) {
rsyserr(FLOG, errno, "pre-xfer exec preparation failed");
io_printf(f_out, "@ERROR: pre-xfer exec preparation failed\n");
return -1;
}
}
if (*lp_name_converter(module_id)) {
namecvt_pid = start_pre_exec(lp_name_converter(module_id), &namecvt_fd_req, &namecvt_fd_ans);
if (namecvt_pid == (pid_t)-1) {
rsyserr(FLOG, errno, "name-converter exec preparation failed");
io_printf(f_out, "@ERROR: name-converter exec preparation failed\n");
return -1;
}
}
}
#endif
if (early_input) {
free(early_input);
early_input = NULL;
}
if (use_chroot) {
/*
* XXX: The 'use chroot' flag is a fairly reliable
* source of confusion, because it fails under two
* important circumstances: running as non-root,
* running on Win32 (or possibly others). On the
* other hand, if you are running as root, then it
* might be better to always use chroot.
*
* So, perhaps if we can't chroot we should just issue
* a warning, unless a "require chroot" flag is set,
* in which case we fail.
*/
if (chroot(module_chdir)) {
rsyserr(FLOG, errno, "chroot %s failed", module_chdir);
io_printf(f_out, "@ERROR: chroot failed\n");
return -1;
}
module_chdir = module_dir;
}
if (!change_dir(module_chdir, CD_NORMAL))
return path_failure(f_out, module_chdir, True);
if (module_dirlen || (!use_chroot && !*lp_daemon_chroot()))
sanitize_paths = 1;
if ((munge_symlinks = lp_munge_symlinks(module_id)) < 0)
munge_symlinks = !use_chroot || module_dirlen;
if (munge_symlinks) {
STRUCT_STAT st;
char prefix[SYMLINK_PREFIX_LEN]; /* NOT +1 ! */
strlcpy(prefix, SYMLINK_PREFIX, sizeof prefix); /* trim the trailing slash */
if (do_stat(prefix, &st) == 0 && S_ISDIR(st.st_mode)) {
rprintf(FLOG, "Symlink munging is unsafe when a %s directory exists.\n",
prefix);
io_printf(f_out, "@ERROR: daemon security issue -- contact admin\n", name);
exit_cleanup(RERR_UNSUPPORTED);
}
}
if (gid_list.count) {
gid_t *gid_array = gid_list.items;
if (setgid(gid_array[0])) {
rsyserr(FLOG, errno, "setgid %ld failed", (long)gid_array[0]);
io_printf(f_out, "@ERROR: setgid failed\n");
return -1;
}
#ifdef HAVE_SETGROUPS
/* Set the group(s) we want to be active. */
if (setgroups(gid_list.count, gid_array)) {
rsyserr(FLOG, errno, "setgroups failed");
io_printf(f_out, "@ERROR: setgroups failed\n");
return -1;
}
#endif
#if defined HAVE_INITGROUPS && !defined HAVE_GETGROUPLIST
/* pw is set if the user wants all the user's groups. */
if (pw && initgroups(pw->pw_name, pw->pw_gid) < 0) {
rsyserr(FLOG, errno, "initgroups failed");
io_printf(f_out, "@ERROR: initgroups failed\n");
return -1;
}
#endif
our_gid = MY_GID();
}
if (set_uid) {
if (setuid(uid) < 0
#ifdef HAVE_SETEUID
|| seteuid(uid) < 0
#endif
) {
rsyserr(FLOG, errno, "setuid %ld failed", (long)uid);
io_printf(f_out, "@ERROR: setuid failed\n");
return -1;
}
our_uid = MY_UID();
am_root = (our_uid == ROOT_UID);
}
if (lp_temp_dir(module_id) && *lp_temp_dir(module_id)) {
tmpdir = lp_temp_dir(module_id);
if (strlen(tmpdir) >= MAXPATHLEN - 10) {
rprintf(FLOG,
"the 'temp dir' value for %s is WAY too long -- ignoring.\n",
name);
tmpdir = NULL;
}
}
io_printf(f_out, "@RSYNCD: OK\n");
read_args(f_in, name, line, sizeof line, rl_nulls, &argv, &argc, &request);
orig_argv = argv;
save_munge_symlinks = munge_symlinks;
reset_output_levels(); /* future verbosity is controlled by client options */
ret = parse_arguments(&argc, (const char ***) &argv);
if (protect_args && ret) {
orig_early_argv = orig_argv;
protect_args = 2;
read_args(f_in, name, line, sizeof line, 1, &argv, &argc, &request);
orig_argv = argv;
ret = parse_arguments(&argc, (const char ***) &argv);
} else
orig_early_argv = NULL;
/* The default is to use the user's setting unless the module sets True or False. */
if (lp_open_noatime(module_id) >= 0)
open_noatime = lp_open_noatime(module_id);
munge_symlinks = save_munge_symlinks; /* The client mustn't control this. */
if (am_daemon > 0)
msgs2stderr = 0; /* A non-rsh-run daemon doesn't have stderr for msgs. */
if (pre_exec_pid) {
write_pre_exec_args(pre_exec_arg_fd, request, orig_early_argv, orig_argv, 0);
err_msg = finish_pre_exec("pre-xfer exec", pre_exec_pid, pre_exec_error_fd);
}
if (namecvt_pid)
write_pre_exec_args(namecvt_fd_req, request, orig_early_argv, orig_argv, 2);
if (orig_early_argv)
free(orig_early_argv);
am_server = 1; /* Don't let someone try to be tricky. */
quiet = 0;
db_config = NULL;
if (lp_ignore_errors(module_id))
ignore_errors = 1;
if (write_batch < 0)
dry_run = 1;
if (lp_fake_super(module_id)) {
if (preserve_xattrs > 1)
preserve_xattrs = 1;
am_root = -1;
} else if (am_root < 0) /* Treat --fake-super from client as --super. */
am_root = 2;
checksum_files = always_checksum ? lp_checksum_files(i)
: CSF_IGNORE_FILES;
if (filesfrom_fd == 0)
filesfrom_fd = f_in;
if (request) {
if (*auth_user) {
rprintf(FLOG, "rsync %s %s from %s@%s (%s)\n",
am_sender ? "on" : "to",
request, auth_user, host, addr);
} else {
rprintf(FLOG, "rsync %s %s from %s (%s)\n",
am_sender ? "on" : "to",
request, host, addr);
}
free(request);
}
#ifndef DEBUG
/* don't allow the logs to be flooded too fast */
limit_output_verbosity(lp_max_verbosity(module_id));
#endif
if (protocol_version < 23 && (protocol_version == 22 || am_sender))
io_start_multiplex_out(f_out);
else if (!ret || err_msg) {
/* We have to get I/O multiplexing started so that we can
* get the error back to the client. This means getting
* the protocol setup finished first in later versions. */
setup_protocol(f_out, f_in);
if (!am_sender) {
/* Since we failed in our option parsing, we may not
* have finished parsing that the client sent us a
* --files-from option, so look for it manually.
* Without this, the socket would be in the wrong
* state for the upcoming error message. */
if (!files_from) {
int i;
for (i = 0; i < argc; i++) {
if (strncmp(argv[i], "--files-from", 12) == 0) {
files_from = "";
break;
}
}
}
if (files_from)
write_byte(f_out, 0);
}
io_start_multiplex_out(f_out);
}
if (!ret || err_msg) {
if (err_msg) {
while ((p = strchr(err_msg, '\n')) != NULL) {
int len = p - err_msg + 1;
rwrite(FERROR, err_msg, len, 0);
err_msg += len;
}
if (*err_msg)
rprintf(FERROR, "%s\n", err_msg);
io_flush(MSG_FLUSH);
} else
option_error();
msleep(400);
exit_cleanup(RERR_UNSUPPORTED);
}
#ifdef ICONV_OPTION
if (!iconv_opt) {
if (ic_send != (iconv_t)-1) {
iconv_close(ic_send);
ic_send = (iconv_t)-1;
}
if (ic_recv != (iconv_t)-1) {
iconv_close(ic_recv);
ic_recv = (iconv_t)-1;
}
}
#endif
if (!numeric_ids
&& (use_chroot ? lp_numeric_ids(module_id) != False && !*lp_name_converter(module_id)
: lp_numeric_ids(module_id) == True))
numeric_ids = -1; /* Set --numeric-ids w/o breaking protocol. */
if (lp_timeout(module_id) && (!io_timeout || lp_timeout(module_id) < io_timeout))
set_io_timeout(lp_timeout(module_id));
/* If we have some incoming/outgoing chmod changes, append them to
* any user-specified changes (making our changes have priority).
* We also get a pointer to just our changes so that a receiver
* process can use them separately if --perms wasn't specified. */
if (am_sender)
p = lp_outgoing_chmod(module_id);
else
p = lp_incoming_chmod(module_id);
if (*p && !(daemon_chmod_modes = parse_chmod(p, &chmod_modes))) {
rprintf(FLOG, "Invalid \"%sing chmod\" directive: %s\n",
am_sender ? "outgo" : "incom", p);
}
start_server(f_in, f_out, argc, argv);
return 0;
}
BOOL namecvt_call(const char *cmd, const char **name_p, id_t *id_p)
{
char buf[1024];
int got, len;
if (*name_p)
len = snprintf(buf, sizeof buf, "%s %s\n", cmd, *name_p);
else
len = snprintf(buf, sizeof buf, "%s %ld\n", cmd, (long)*id_p);
if (len >= (int)sizeof buf) {
rprintf(FERROR, "namecvt_call() request was too large.\n");
exit_cleanup(RERR_UNSUPPORTED);
}
while ((got = write(namecvt_fd_req, buf, len)) != len) {
if (got < 0 && errno == EINTR)
continue;
rprintf(FERROR, "Connection to name-converter failed.\n");
exit_cleanup(RERR_SOCKETIO);
}
if (!read_line_old(namecvt_fd_ans, buf, sizeof buf, 0))
return False;
if (*name_p)
*id_p = (id_t)atol(buf);
else
*name_p = strdup(buf);
return True;
}
/* send a list of available modules to the client. Don't list those
with "list = False". */
static void send_listing(int fd)
{
int n = lp_num_modules();
int i;
for (i = 0; i < n; i++) {
if (lp_list(i))
io_printf(fd, "%-15s\t%s\n", lp_name(i), lp_comment(i));
}
if (protocol_version >= 25)
io_printf(fd,"@RSYNCD: EXIT\n");
}
static int load_config(int globals_only)
{
if (!config_file) {
if (am_daemon < 0 && am_root <= 0)
config_file = RSYNCD_USERCONF;
else
config_file = RSYNCD_SYSCONF;
}
return lp_load(config_file, globals_only);
}
/* this is called when a connection is established to a client
and we want to start talking. The setup of the system is done from
here */
int start_daemon(int f_in, int f_out)
{
char line[1024];
const char *addr, *host;
char *p;
int i;
/* At this point, am_server is only set for a daemon started via rsh.
* Because am_server gets forced on soon, we'll set am_daemon to -1 as
* a flag that can be checked later on to distinguish a normal daemon
* from an rsh-run daemon. */
if (am_server)
am_daemon = -1;
io_set_sock_fds(f_in, f_out);
/* We must load the config file before calling any function that
* might cause log-file output to occur. This ensures that the
* "log file" param gets honored for the 2 non-forked use-cases
* (when rsync is run by init and run by a remote shell). */
if (!load_config(0))
exit_cleanup(RERR_SYNTAX);
if (lp_proxy_protocol() && !read_proxy_protocol_header(f_in))
return -1;
p = lp_daemon_chroot();
if (*p) {
log_init(0); /* Make use we've initialized syslog before chrooting. */
if (chroot(p) < 0 || chdir("/") < 0) {
rsyserr(FLOG, errno, "daemon chroot %s failed", p);
return -1;
}
}
p = lp_daemon_gid();
if (*p) {
gid_t gid;
if (!group_to_gid(p, &gid, True)) {
rprintf(FLOG, "Invalid daemon gid: %s\n", p);
return -1;
}
if (setgid(gid) < 0) {
rsyserr(FLOG, errno, "Unable to set group to daemon gid %ld", (long)gid);
return -1;
}
our_gid = MY_GID();
}
p = lp_daemon_uid();
if (*p) {
uid_t uid;
if (!user_to_uid(p, &uid, True)) {
rprintf(FLOG, "Invalid daemon uid: %s\n", p);
return -1;
}
if (setuid(uid) < 0) {
rsyserr(FLOG, errno, "Unable to set user to daemon uid %ld", (long)uid);
return -1;
}
our_uid = MY_UID();
am_root = (our_uid == ROOT_UID);
}
addr = client_addr(f_in);
host = lp_reverse_lookup(-1) ? client_name(addr) : undetermined_hostname;
rprintf(FLOG, "connect from %s (%s)\n", host, addr);
if (am_daemon > 0) {
set_socket_options(f_in, "SO_KEEPALIVE");
set_nonblocking(f_in);
}
if (exchange_protocols(f_in, f_out, line, sizeof line, 0) < 0)
return -1;
line[0] = 0;
if (!read_line_old(f_in, line, sizeof line, 0))
return -1;
if (strncmp(line, EARLY_INPUT_CMD, EARLY_INPUT_CMDLEN) == 0) {
early_input_len = strtol(line + EARLY_INPUT_CMDLEN, NULL, 10);
if (early_input_len <= 0 || early_input_len > BIGPATHBUFLEN) {
io_printf(f_out, "@ERROR: invalid early_input length\n");
return -1;
}
early_input = new_array(char, early_input_len);
read_buf(f_in, early_input, early_input_len);
if (!read_line_old(f_in, line, sizeof line, 0))
return -1;
}
if (!*line || strcmp(line, "#list") == 0) {
rprintf(FLOG, "module-list request from %s (%s)\n",
host, addr);
send_listing(f_out);
return -1;
}
if (*line == '#') {
/* it's some sort of command that I don't understand */
io_printf(f_out, "@ERROR: Unknown command '%s'\n", line);
return -1;
}
if ((i = lp_number(line)) < 0) {
rprintf(FLOG, "unknown module '%s' tried from %s (%s)\n",
line, host, addr);
io_printf(f_out, "@ERROR: Unknown module '%s'\n", line);
return -1;
}
#ifdef HAVE_SIGACTION
sigact.sa_flags = SA_NOCLDSTOP;
#endif
SIGACTION(SIGCHLD, remember_children);
return rsync_module(f_in, f_out, i, addr, host);
}
static void create_pid_file(void)
{
char *pid_file = lp_pid_file();
char pidbuf[32];
STRUCT_STAT st1, st2;
char *fail = NULL;
if (!pid_file || !*pid_file)
return;
#ifdef O_NOFOLLOW
#define SAFE_OPEN_FLAGS (O_CREAT|O_NOFOLLOW)
#else
#define SAFE_OPEN_FLAGS (O_CREAT)
#endif
/* These tests make sure that a temp-style lock dir is handled safely. */
st1.st_mode = 0;
if (do_lstat(pid_file, &st1) == 0 && !S_ISREG(st1.st_mode) && unlink(pid_file) < 0)
fail = "unlink";
else if ((pid_file_fd = do_open(pid_file, O_RDWR|SAFE_OPEN_FLAGS, 0664)) < 0)
fail = S_ISREG(st1.st_mode) ? "open" : "create";
else if (!lock_range(pid_file_fd, 0, 4))
fail = "lock";
else if (do_fstat(pid_file_fd, &st1) < 0)
fail = "fstat opened";
else if (st1.st_size > (int)sizeof pidbuf)
fail = "find small";
else if (do_lstat(pid_file, &st2) < 0)
fail = "lstat";
else if (!S_ISREG(st1.st_mode))
fail = "avoid file overwrite race for";
else if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
fail = "verify stat info for";
#ifdef HAVE_FTRUNCATE
else if (do_ftruncate(pid_file_fd, 0) < 0)
fail = "truncate";
#endif
else {
pid_t pid = getpid();
int len = snprintf(pidbuf, sizeof pidbuf, "%d\n", (int)pid);
#ifndef HAVE_FTRUNCATE
/* What can we do with a too-long file and no truncate? I guess we'll add extra newlines. */
while (len < st1.st_size) /* We already verified that st_size chars fits in the buffer. */
pidbuf[len++] = '\n';
/* We don't need the buffer to end in a '\0' (and we may not have room to add it). */
#endif
if (write(pid_file_fd, pidbuf, len) != len)
fail = "write";
cleanup_set_pid(pid); /* Mark the file for removal on exit, even if the write failed. */
}
if (fail) {
char msg[1024];
snprintf(msg, sizeof msg, "failed to %s pid file %s: %s\n",
fail, pid_file, strerror(errno));
fputs(msg, stderr);
rprintf(FLOG, "%s", msg);
exit_cleanup(RERR_FILEIO);
}
/* The file is left open so that the lock remains valid. It is closed in our forked child procs. */
}
/* Become a daemon, discarding the controlling terminal. */
static void become_daemon(void)
{
int i;
pid_t pid = fork();
if (pid) {
if (pid < 0) {
fprintf(stderr, "failed to fork: %s\n", strerror(errno));
exit_cleanup(RERR_FILEIO);
}
_exit(0);
}
create_pid_file();
/* detach from the terminal */
#ifdef HAVE_SETSID
setsid();
#elif defined TIOCNOTTY
i = open("/dev/tty", O_RDWR);
if (i >= 0) {
ioctl(i, (int)TIOCNOTTY, (char *)0);
close(i);
}
#endif
/* make sure that stdin, stdout an stderr don't stuff things
* up (library functions, for example) */
for (i = 0; i < 3; i++) {
close(i);
open("/dev/null", O_RDWR);
}
}
int daemon_main(void)
{
if (is_a_socket(STDIN_FILENO)) {
int i;
/* we are running via inetd - close off stdout and
* stderr so that library functions (and getopt) don't
* try to use them. Redirect them to /dev/null */
for (i = 1; i < 3; i++) {
close(i);
open("/dev/null", O_RDWR);
}
return start_daemon(STDIN_FILENO, STDIN_FILENO);
}
if (!load_config(1)) {
fprintf(stderr, "Failed to parse config file: %s\n", config_file);
exit_cleanup(RERR_SYNTAX);
}
set_dparams(0);
if (no_detach)
create_pid_file();
else
become_daemon();
if (rsync_port == 0 && (rsync_port = lp_rsync_port()) == 0)
rsync_port = RSYNC_PORT;
if (bind_address == NULL && *lp_bind_address())
bind_address = lp_bind_address();
log_init(0);
rprintf(FLOG, "rsyncd version %s starting, listening on port %d\n",
rsync_version(), rsync_port);
/* TODO: If listening on a particular address, then show that
* address too. In fact, why not just do getnameinfo on the
* local address??? */
#ifdef HAVE_LIBSLP
if (lp_use_slp() && register_services()) {
rprintf(FINFO,
"Couldn't register with service discovery protocol, continuing anyway\n");
}
#endif
start_accept_loop(rsync_port, start_daemon);
return -1;
}
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