usr.sbin/ctld/discovery.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2012 The FreeBSD Foundation
   5  * All rights reserved.
   6  *
   7  * This software was developed by Edward Tomasz Napierala under sponsorship
   8  * from the FreeBSD Foundation.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  */
  32
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD$");
  35
  36 #include <assert.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <netinet/in.h>
  41 #include <netdb.h>
  42 #include <sys/socket.h>
  43
  44 #include "ctld.h"
  45 #include "iscsi_proto.h"
  46
  47 static struct pdu *
  48 text_receive(struct connection *conn)
  49 {
  50         struct pdu *request;
  51         struct iscsi_bhs_text_request *bhstr;
  52
  53         request = pdu_new(conn);
  54         pdu_receive(request);
  55         if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
  56             ISCSI_BHS_OPCODE_TEXT_REQUEST)
  57                 log_errx(1, "protocol error: received invalid opcode 0x%x",
  58                     request->pdu_bhs->bhs_opcode);
  59         bhstr = (struct iscsi_bhs_text_request *)request->pdu_bhs;
  60 #if 0
  61         if ((bhstr->bhstr_flags & ISCSI_BHSTR_FLAGS_FINAL) == 0)
  62                 log_errx(1, "received Text PDU without the \"F\" flag");
  63 #endif
  64         /*
  65          * XXX: Implement the C flag some day.
  66          */
  67         if ((bhstr->bhstr_flags & BHSTR_FLAGS_CONTINUE) != 0)
  68                 log_errx(1, "received Text PDU with unsupported \"C\" flag");
  69         if (ISCSI_SNLT(ntohl(bhstr->bhstr_cmdsn), conn->conn_cmdsn)) {
  70                 log_errx(1, "received Text PDU with decreasing CmdSN: "
  71                     "was %u, is %u", conn->conn_cmdsn, ntohl(bhstr->bhstr_cmdsn));
  72         }
  73         if (ntohl(bhstr->bhstr_expstatsn) != conn->conn_statsn) {
  74                 log_errx(1, "received Text PDU with wrong ExpStatSN: "
  75                     "is %u, should be %u", ntohl(bhstr->bhstr_expstatsn),
  76                     conn->conn_statsn);
  77         }
  78         conn->conn_cmdsn = ntohl(bhstr->bhstr_cmdsn);
  79         if ((bhstr->bhstr_opcode & ISCSI_BHS_OPCODE_IMMEDIATE) == 0)
  80                 conn->conn_cmdsn++;
  81
  82         return (request);
  83 }
  84
  85 static struct pdu *
  86 text_new_response(struct pdu *request)
  87 {
  88         struct pdu *response;
  89         struct connection *conn;
  90         struct iscsi_bhs_text_request *bhstr;
  91         struct iscsi_bhs_text_response *bhstr2;
  92
  93         bhstr = (struct iscsi_bhs_text_request *)request->pdu_bhs;
  94         conn = request->pdu_connection;
  95
  96         response = pdu_new_response(request);
  97         bhstr2 = (struct iscsi_bhs_text_response *)response->pdu_bhs;
  98         bhstr2->bhstr_opcode = ISCSI_BHS_OPCODE_TEXT_RESPONSE;
  99         bhstr2->bhstr_flags = BHSTR_FLAGS_FINAL;
 100         bhstr2->bhstr_lun = bhstr->bhstr_lun;
 101         bhstr2->bhstr_initiator_task_tag = bhstr->bhstr_initiator_task_tag;
 102         bhstr2->bhstr_target_transfer_tag = bhstr->bhstr_target_transfer_tag;
 103         bhstr2->bhstr_statsn = htonl(conn->conn_statsn++);
 104         bhstr2->bhstr_expcmdsn = htonl(conn->conn_cmdsn);
 105         bhstr2->bhstr_maxcmdsn = htonl(conn->conn_cmdsn);
 106
 107         return (response);
 108 }
 109
 110 static struct pdu *
 111 logout_receive(struct connection *conn)
 112 {
 113         struct pdu *request;
 114         struct iscsi_bhs_logout_request *bhslr;
 115
 116         request = pdu_new(conn);
 117         pdu_receive(request);
 118         if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
 119             ISCSI_BHS_OPCODE_LOGOUT_REQUEST)
 120                 log_errx(1, "protocol error: received invalid opcode 0x%x",
 121                     request->pdu_bhs->bhs_opcode);
 122         bhslr = (struct iscsi_bhs_logout_request *)request->pdu_bhs;
 123         if ((bhslr->bhslr_reason & 0x7f) != BHSLR_REASON_CLOSE_SESSION)
 124                 log_debugx("received Logout PDU with invalid reason 0x%x; "
 125                     "continuing anyway", bhslr->bhslr_reason & 0x7f);
 126         if (ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) {
 127                 log_errx(1, "received Logout PDU with decreasing CmdSN: "
 128                     "was %u, is %u", conn->conn_cmdsn,
 129                     ntohl(bhslr->bhslr_cmdsn));
 130         }
 131         if (ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) {
 132                 log_errx(1, "received Logout PDU with wrong ExpStatSN: "
 133                     "is %u, should be %u", ntohl(bhslr->bhslr_expstatsn),
 134                     conn->conn_statsn);
 135         }
 136         conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
 137         if ((bhslr->bhslr_opcode & ISCSI_BHS_OPCODE_IMMEDIATE) == 0)
 138                 conn->conn_cmdsn++;
 139
 140         return (request);
 141 }
 142
 143 static struct pdu *
 144 logout_new_response(struct pdu *request)
 145 {
 146         struct pdu *response;
 147         struct connection *conn;
 148         struct iscsi_bhs_logout_request *bhslr;
 149         struct iscsi_bhs_logout_response *bhslr2;
 150
 151         bhslr = (struct iscsi_bhs_logout_request *)request->pdu_bhs;
 152         conn = request->pdu_connection;
 153
 154         response = pdu_new_response(request);
 155         bhslr2 = (struct iscsi_bhs_logout_response *)response->pdu_bhs;
 156         bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_RESPONSE;
 157         bhslr2->bhslr_flags = 0x80;
 158         bhslr2->bhslr_response = BHSLR_RESPONSE_CLOSED_SUCCESSFULLY;
 159         bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag;
 160         bhslr2->bhslr_statsn = htonl(conn->conn_statsn++);
 161         bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn);
 162         bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn);
 163
 164         return (response);
 165 }
 166
 167 static void
 168 discovery_add_target(struct keys *response_keys, const struct target *targ)
 169 {
 170         struct port *port;
 171         struct portal *portal;
 172         char *buf;
 173         char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
 174         struct addrinfo *ai;
 175         int ret;
 176
 177         keys_add(response_keys, "TargetName", targ->t_name);
 178         TAILQ_FOREACH(port, &targ->t_ports, p_ts) {
 179             if (port->p_portal_group == NULL)
 180                 continue;
 181             TAILQ_FOREACH(portal, &port->p_portal_group->pg_portals, p_next) {
 182                 ai = portal->p_ai;
 183                 ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
 184                     hbuf, sizeof(hbuf), sbuf, sizeof(sbuf),
 185                     NI_NUMERICHOST | NI_NUMERICSERV);
 186                 if (ret != 0) {
 187                         log_warnx("getnameinfo: %s", gai_strerror(ret));
 188                         continue;
 189                 }
 190                 switch (ai->ai_addr->sa_family) {
 191                 case AF_INET:
 192                         if (strcmp(hbuf, "0.0.0.0") == 0)
 193                                 continue;
 194                         ret = asprintf(&buf, "%s:%s,%d", hbuf, sbuf,
 195                             port->p_portal_group->pg_tag);
 196                         break;
 197                 case AF_INET6:
 198                         if (strcmp(hbuf, "::") == 0)
 199                                 continue;
 200                         ret = asprintf(&buf, "[%s]:%s,%d", hbuf, sbuf,
 201                             port->p_portal_group->pg_tag);
 202                         break;
 203                 default:
 204                         continue;
 205                 }
 206                 if (ret <= 0)
 207                     log_err(1, "asprintf");
 208                 keys_add(response_keys, "TargetAddress", buf);
 209                 free(buf);
 210             }
 211         }
 212 }
 213
 214 static bool
 215 discovery_target_filtered_out(const struct connection *conn,
 216     const struct port *port)
 217 {
 218         const struct auth_group *ag;
 219         const struct portal_group *pg;
 220         const struct target *targ;
 221         const struct auth *auth;
 222         int error;
 223
 224         targ = port->p_target;
 225         ag = port->p_auth_group;
 226         if (ag == NULL)
 227                 ag = targ->t_auth_group;
 228         pg = conn->conn_portal->p_portal_group;
 229
 230         assert(pg->pg_discovery_auth_group != PG_FILTER_UNKNOWN);
 231
 232         if (pg->pg_discovery_filter >= PG_FILTER_PORTAL &&
 233             auth_portal_check(ag, &conn->conn_initiator_sa) != 0) {
 234                 log_debugx("initiator does not match initiator portals "
 235                     "allowed for target \"%s\"; skipping", targ->t_name);
 236                 return (true);
 237         }
 238
 239         if (pg->pg_discovery_filter >= PG_FILTER_PORTAL_NAME &&
 240             auth_name_check(ag, conn->conn_initiator_name) != 0) {
 241                 log_debugx("initiator does not match initiator names "
 242                     "allowed for target \"%s\"; skipping", targ->t_name);
 243                 return (true);
 244         }
 245
 246         if (pg->pg_discovery_filter >= PG_FILTER_PORTAL_NAME_AUTH &&
 247             ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
 248                 if (conn->conn_chap == NULL) {
 249                         assert(pg->pg_discovery_auth_group->ag_type ==
 250                             AG_TYPE_NO_AUTHENTICATION);
 251
 252                         log_debugx("initiator didn't authenticate, but target "
 253                             "\"%s\" requires CHAP; skipping", targ->t_name);
 254                         return (true);
 255                 }
 256
 257                 assert(conn->conn_user != NULL);
 258                 auth = auth_find(ag, conn->conn_user);
 259                 if (auth == NULL) {
 260                         log_debugx("CHAP user \"%s\" doesn't match target "
 261                             "\"%s\"; skipping", conn->conn_user, targ->t_name);
 262                         return (true);
 263                 }
 264
 265                 error = chap_authenticate(conn->conn_chap, auth->a_secret);
 266                 if (error != 0) {
 267                         log_debugx("password for CHAP user \"%s\" doesn't "
 268                             "match target \"%s\"; skipping",
 269                             conn->conn_user, targ->t_name);
 270                         return (true);
 271                 }
 272         }
 273
 274         return (false);
 275 }
 276
 277 void
 278 discovery(struct connection *conn)
 279 {
 280         struct pdu *request, *response;
 281         struct keys *request_keys, *response_keys;
 282         const struct port *port;
 283         const struct portal_group *pg;
 284         const char *send_targets;
 285
 286         pg = conn->conn_portal->p_portal_group;
 287
 288         log_debugx("beginning discovery session; waiting for Text PDU");
 289         request = text_receive(conn);
 290         request_keys = keys_new();
 291         keys_load(request_keys, request);
 292
 293         send_targets = keys_find(request_keys, "SendTargets");
 294         if (send_targets == NULL)
 295                 log_errx(1, "received Text PDU without SendTargets");
 296
 297         response = text_new_response(request);
 298         response_keys = keys_new();
 299
 300         if (strcmp(send_targets, "All") == 0) {
 301                 TAILQ_FOREACH(port, &pg->pg_ports, p_pgs) {
 302                         if (discovery_target_filtered_out(conn, port)) {
 303                                 /* Ignore this target. */
 304                                 continue;
 305                         }
 306                         discovery_add_target(response_keys, port->p_target);
 307                 }
 308         } else {
 309                 port = port_find_in_pg(pg, send_targets);
 310                 if (port == NULL) {
 311                         log_debugx("initiator requested information on unknown "
 312                             "target \"%s\"; returning nothing", send_targets);
 313                 } else {
 314                         if (discovery_target_filtered_out(conn, port)) {
 315                                 /* Ignore this target. */
 316                         } else {
 317                                 discovery_add_target(response_keys, port->p_target);
 318                         }
 319                 }
 320         }
 321         keys_save(response_keys, response);
 322
 323         pdu_send(response);
 324         pdu_delete(response);
 325         keys_delete(response_keys);
 326         pdu_delete(request);
 327         keys_delete(request_keys);
 328
 329         log_debugx("done sending targets; waiting for Logout PDU");
 330         request = logout_receive(conn);
 331         response = logout_new_response(request);
 332
 333         pdu_send(response);
 334         pdu_delete(response);
 335         pdu_delete(request);
 336
 337         log_debugx("discovery session done");
 338 }