freebsd-dev/usr.sbin/iscsid/iscsid.c

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/*-
* Copyright (c) 2012 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Edward Tomasz Napierala under sponsorship
* from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/types.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/linker.h>
#include <sys/socket.h>
#include <sys/capability.h>
#include <sys/wait.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <signal.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libutil.h>
#include "iscsid.h"
static volatile bool sigalrm_received = false;
static int nchildren = 0;
static void
usage(void)
{
fprintf(stderr, "usage: iscsid [-P pidfile][-d][-m maxproc][-t timeout]\n");
exit(1);
}
char *
checked_strdup(const char *s)
{
char *c;
c = strdup(s);
if (c == NULL)
log_err(1, "strdup");
return (c);
}
static void
resolve_addr(const struct connection *conn, const char *address,
struct addrinfo **ai, bool initiator_side)
{
struct addrinfo hints;
char *arg, *addr, *ch;
const char *port;
int error, colons = 0;
arg = checked_strdup(address);
if (arg[0] == '\0') {
fail(conn, "empty address");
log_errx(1, "empty address");
}
if (arg[0] == '[') {
/*
* IPv6 address in square brackets, perhaps with port.
*/
arg++;
addr = strsep(&arg, "]");
if (arg == NULL) {
fail(conn, "malformed address");
log_errx(1, "malformed address %s", address);
}
if (arg[0] == '\0') {
port = NULL;
} else if (arg[0] == ':') {
port = arg + 1;
} else {
fail(conn, "malformed address");
log_errx(1, "malformed address %s", address);
}
} else {
/*
* Either IPv6 address without brackets - and without
* a port - or IPv4 address. Just count the colons.
*/
for (ch = arg; *ch != '\0'; ch++) {
if (*ch == ':')
colons++;
}
if (colons > 1) {
addr = arg;
port = NULL;
} else {
addr = strsep(&arg, ":");
if (arg == NULL)
port = NULL;
else
port = arg;
}
}
if (port == NULL && !initiator_side)
port = "3260";
memset(&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_ADDRCONFIG | AI_NUMERICSERV;
if (initiator_side)
hints.ai_flags |= AI_PASSIVE;
error = getaddrinfo(addr, port, &hints, ai);
if (error != 0) {
fail(conn, gai_strerror(error));
log_errx(1, "getaddrinfo for %s failed: %s",
address, gai_strerror(error));
}
}
static struct connection *
connection_new(unsigned int session_id, const struct iscsi_session_conf *conf,
int iscsi_fd)
{
struct connection *conn;
struct addrinfo *from_ai, *to_ai;
const char *from_addr, *to_addr;
#ifdef ICL_KERNEL_PROXY
struct iscsi_daemon_connect idc;
#endif
int error;
conn = calloc(1, sizeof(*conn));
if (conn == NULL)
log_err(1, "calloc");
/*
* Default values, from RFC 3720, section 12.
*/
conn->conn_header_digest = CONN_DIGEST_NONE;
conn->conn_data_digest = CONN_DIGEST_NONE;
conn->conn_initial_r2t = true;
conn->conn_immediate_data = true;
conn->conn_max_data_segment_length = 8192;
conn->conn_max_burst_length = 262144;
conn->conn_first_burst_length = 65536;
conn->conn_session_id = session_id;
conn->conn_iscsi_fd = iscsi_fd;
/*
* XXX: Should we sanitize this somehow?
*/
memcpy(&conn->conn_conf, conf, sizeof(conn->conn_conf));
from_addr = conn->conn_conf.isc_initiator_addr;
to_addr = conn->conn_conf.isc_target_addr;
if (from_addr[0] != '\0')
resolve_addr(conn, from_addr, &from_ai, true);
else
from_ai = NULL;
resolve_addr(conn, to_addr, &to_ai, false);
#ifdef ICL_KERNEL_PROXY
memset(&idc, 0, sizeof(idc));
idc.idc_session_id = conn->conn_session_id;
if (conn->conn_conf.isc_iser)
idc.idc_iser = 1;
idc.idc_domain = to_ai->ai_family;
idc.idc_socktype = to_ai->ai_socktype;
idc.idc_protocol = to_ai->ai_protocol;
if (from_ai != NULL) {
idc.idc_from_addr = from_ai->ai_addr;
idc.idc_from_addrlen = from_ai->ai_addrlen;
}
idc.idc_to_addr = to_ai->ai_addr;
idc.idc_to_addrlen = to_ai->ai_addrlen;
log_debugx("connecting to %s using ICL kernel proxy", to_addr);
error = ioctl(iscsi_fd, ISCSIDCONNECT, &idc);
if (error != 0) {
fail(conn, strerror(errno));
log_err(1, "failed to connect to %s using ICL kernel proxy",
to_addr);
}
#else /* !ICL_KERNEL_PROXY */
if (conn->conn_conf.isc_iser) {
fail(conn, "iSER not supported");
log_errx(1, "iscsid(8) compiled without ICL_KERNEL_PROXY "
"does not support iSER");
}
conn->conn_socket = socket(to_ai->ai_family, to_ai->ai_socktype,
to_ai->ai_protocol);
if (conn->conn_socket < 0) {
fail(conn, strerror(errno));
log_err(1, "failed to create socket for %s", from_addr);
}
if (from_ai != NULL) {
error = bind(conn->conn_socket, from_ai->ai_addr,
from_ai->ai_addrlen);
if (error != 0) {
fail(conn, strerror(errno));
log_err(1, "failed to bind to %s", from_addr);
}
}
log_debugx("connecting to %s", to_addr);
error = connect(conn->conn_socket, to_ai->ai_addr, to_ai->ai_addrlen);
if (error != 0) {
fail(conn, strerror(errno));
log_err(1, "failed to connect to %s", to_addr);
}
#endif /* !ICL_KERNEL_PROXY */
return (conn);
}
static void
handoff(struct connection *conn)
{
struct iscsi_daemon_handoff idh;
int error;
log_debugx("handing off connection to the kernel");
memset(&idh, 0, sizeof(idh));
idh.idh_session_id = conn->conn_session_id;
#ifndef ICL_KERNEL_PROXY
idh.idh_socket = conn->conn_socket;
#endif
strlcpy(idh.idh_target_alias, conn->conn_target_alias,
sizeof(idh.idh_target_alias));
memcpy(idh.idh_isid, conn->conn_isid, sizeof(idh.idh_isid));
idh.idh_statsn = conn->conn_statsn;
idh.idh_header_digest = conn->conn_header_digest;
idh.idh_data_digest = conn->conn_data_digest;
idh.idh_initial_r2t = conn->conn_initial_r2t;
idh.idh_immediate_data = conn->conn_immediate_data;
idh.idh_max_data_segment_length = conn->conn_max_data_segment_length;
idh.idh_max_burst_length = conn->conn_max_burst_length;
idh.idh_first_burst_length = conn->conn_first_burst_length;
error = ioctl(conn->conn_iscsi_fd, ISCSIDHANDOFF, &idh);
if (error != 0)
log_err(1, "ISCSIDHANDOFF");
}
void
fail(const struct connection *conn, const char *reason)
{
struct iscsi_daemon_fail idf;
int error;
memset(&idf, 0, sizeof(idf));
idf.idf_session_id = conn->conn_session_id;
strlcpy(idf.idf_reason, reason, sizeof(idf.idf_reason));
error = ioctl(conn->conn_iscsi_fd, ISCSIDFAIL, &idf);
if (error != 0)
log_err(1, "ISCSIDFAIL");
}
/*
* XXX: I CANT INTO LATIN
*/
static void
capsicate(struct connection *conn)
{
int error;
cap_rights_t rights;
#ifdef ICL_KERNEL_PROXY
const unsigned long cmds[] = { ISCSIDCONNECT, ISCSIDSEND, ISCSIDRECEIVE,
ISCSIDHANDOFF, ISCSIDFAIL, ISCSISADD, ISCSISREMOVE };
#else
const unsigned long cmds[] = { ISCSIDHANDOFF, ISCSIDFAIL, ISCSISADD,
ISCSISREMOVE };
#endif
cap_rights_init(&rights, CAP_IOCTL);
error = cap_rights_limit(conn->conn_iscsi_fd, &rights);
if (error != 0 && errno != ENOSYS)
log_err(1, "cap_rights_limit");
error = cap_ioctls_limit(conn->conn_iscsi_fd, cmds,
sizeof(cmds) / sizeof(cmds[0]));
if (error != 0 && errno != ENOSYS)
log_err(1, "cap_ioctls_limit");
error = cap_enter();
if (error != 0 && errno != ENOSYS)
log_err(1, "cap_enter");
if (cap_sandboxed())
log_debugx("Capsicum capability mode enabled");
else
log_warnx("Capsicum capability mode not supported");
}
bool
timed_out(void)
{
return (sigalrm_received);
}
static void
sigalrm_handler(int dummy __unused)
{
/*
* It would be easiest to just log an error and exit. We can't
* do this, though, because log_errx() is not signal safe, since
* it calls syslog(3). Instead, set a flag checked by pdu_send()
* and pdu_receive(), to call log_errx() there. Should they fail
* to notice, we'll exit here one second later.
*/
if (sigalrm_received) {
/*
* Oh well. Just give up and quit.
*/
_exit(2);
}
sigalrm_received = true;
}
static void
set_timeout(int timeout)
{
struct sigaction sa;
struct itimerval itv;
int error;
if (timeout <= 0) {
log_debugx("session timeout disabled");
return;
}
bzero(&sa, sizeof(sa));
sa.sa_handler = sigalrm_handler;
sigfillset(&sa.sa_mask);
error = sigaction(SIGALRM, &sa, NULL);
if (error != 0)
log_err(1, "sigaction");
/*
* First SIGALRM will arive after conf_timeout seconds.
* If we do nothing, another one will arrive a second later.
*/
bzero(&itv, sizeof(itv));
itv.it_interval.tv_sec = 1;
itv.it_value.tv_sec = timeout;
log_debugx("setting session timeout to %d seconds",
timeout);
error = setitimer(ITIMER_REAL, &itv, NULL);
if (error != 0)
log_err(1, "setitimer");
}
static void
handle_request(int iscsi_fd, const struct iscsi_daemon_request *request, int timeout)
{
struct connection *conn;
log_set_peer_addr(request->idr_conf.isc_target_addr);
if (request->idr_conf.isc_target[0] != '\0') {
log_set_peer_name(request->idr_conf.isc_target);
setproctitle("%s (%s)", request->idr_conf.isc_target_addr, request->idr_conf.isc_target);
} else {
setproctitle("%s", request->idr_conf.isc_target_addr);
}
conn = connection_new(request->idr_session_id, &request->idr_conf, iscsi_fd);
set_timeout(timeout);
capsicate(conn);
login(conn);
if (conn->conn_conf.isc_discovery != 0)
discovery(conn);
else
handoff(conn);
log_debugx("nothing more to do; exiting");
exit (0);
}
static int
wait_for_children(bool block)
{
pid_t pid;
int status;
int num = 0;
for (;;) {
/*
* If "block" is true, wait for at least one process.
*/
if (block && num == 0)
pid = wait4(-1, &status, 0, NULL);
else
pid = wait4(-1, &status, WNOHANG, NULL);
if (pid <= 0)
break;
if (WIFSIGNALED(status)) {
log_warnx("child process %d terminated with signal %d",
pid, WTERMSIG(status));
} else if (WEXITSTATUS(status) != 0) {
log_warnx("child process %d terminated with exit status %d",
pid, WEXITSTATUS(status));
} else {
log_debugx("child process %d terminated gracefully", pid);
}
num++;
}
return (num);
}
int
main(int argc, char **argv)
{
int ch, debug = 0, error, iscsi_fd, maxproc = 30, retval, saved_errno,
timeout = 60;
bool dont_daemonize = false;
struct pidfh *pidfh;
pid_t pid, otherpid;
const char *pidfile_path = DEFAULT_PIDFILE;
struct iscsi_daemon_request request;
while ((ch = getopt(argc, argv, "P:dl:m:t:")) != -1) {
switch (ch) {
case 'P':
pidfile_path = optarg;
break;
case 'd':
dont_daemonize = true;
debug++;
break;
case 'l':
debug = atoi(optarg);
break;
case 'm':
maxproc = atoi(optarg);
break;
case 't':
timeout = atoi(optarg);
break;
case '?':
default:
usage();
}
}
argc -= optind;
if (argc != 0)
usage();
log_init(debug);
pidfh = pidfile_open(pidfile_path, 0600, &otherpid);
if (pidfh == NULL) {
if (errno == EEXIST)
log_errx(1, "daemon already running, pid: %jd.",
(intmax_t)otherpid);
log_err(1, "cannot open or create pidfile \"%s\"",
pidfile_path);
}
iscsi_fd = open(ISCSI_PATH, O_RDWR);
if (iscsi_fd < 0 && errno == ENOENT) {
saved_errno = errno;
retval = kldload("iscsi");
if (retval != -1)
iscsi_fd = open(ISCSI_PATH, O_RDWR);
else
errno = saved_errno;
}
if (iscsi_fd < 0)
log_err(1, "failed to open %s", ISCSI_PATH);
if (dont_daemonize == false) {
if (daemon(0, 0) == -1) {
log_warn("cannot daemonize");
pidfile_remove(pidfh);
exit(1);
}
}
pidfile_write(pidfh);
for (;;) {
log_debugx("waiting for request from the kernel");
memset(&request, 0, sizeof(request));
error = ioctl(iscsi_fd, ISCSIDWAIT, &request);
if (error != 0) {
if (errno == EINTR) {
nchildren -= wait_for_children(false);
assert(nchildren >= 0);
continue;
}
log_err(1, "ISCSIDWAIT");
}
if (dont_daemonize) {
log_debugx("not forking due to -d flag; "
"will exit after servicing a single request");
} else {
nchildren -= wait_for_children(false);
assert(nchildren >= 0);
while (maxproc > 0 && nchildren >= maxproc) {
log_debugx("maxproc limit of %d child processes hit; "
"waiting for child process to exit", maxproc);
nchildren -= wait_for_children(true);
assert(nchildren >= 0);
}
log_debugx("incoming connection; forking child process #%d",
nchildren);
nchildren++;
pid = fork();
if (pid < 0)
log_err(1, "fork");
if (pid > 0)
continue;
}
pidfile_close(pidfh);
handle_request(iscsi_fd, &request, timeout);
}
return (0);
}