iscsi-target: Fix discovery with INADDR_ANY and IN6ADDR_ANY_INIT

This patch addresses a bug with sendtargets discovery where INADDR_ANY (0.0.0.0)
+ IN6ADDR_ANY_INIT ([0:0:0:0:0:0:0:0]) network portals where incorrectly being
reported back to initiators instead of the address of the connecting interface.
To address this, save local socket ->getname() output during iscsi login setup,
and makes iscsit_build_sendtargets_response() return these TargetAddress keys
when INADDR_ANY or IN6ADDR_ANY_INIT portals are in use.

Reported-by: Dax Kelson <dkelson@gurulabs.com>
Reported-by: Andy Grover <agrover@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

3 files changed, 62 insertions, 8 deletions

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 6e070e0a8393..44262908def5 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -3164,6 +3164,30 @@ static int iscsit_send_task_mgt_rsp(
         return 0;
 }
 
+static bool iscsit_check_inaddr_any(struct iscsi_np *np)
+{
+        bool ret = false;
+
+        if (np->np_sockaddr.ss_family == AF_INET6) {
+                const struct sockaddr_in6 sin6 = {
+                        .sin6_addr = IN6ADDR_ANY_INIT };
+                struct sockaddr_in6 *sock_in6 =
+                         (struct sockaddr_in6 *)&np->np_sockaddr;
+
+                if (!memcmp(sock_in6->sin6_addr.s6_addr,
+                                sin6.sin6_addr.s6_addr, 16))
+                        ret = true;
+        } else {
+                struct sockaddr_in * sock_in =
+                        (struct sockaddr_in *)&np->np_sockaddr;
+
+                if (sock_in->sin_addr.s_addr == INADDR_ANY)
+                        ret = true;
+        }
+
+        return ret;
+}
+
 static int iscsit_build_sendtargets_response(struct iscsi_cmd *cmd)
 {
         char *payload = NULL;
@@ -3213,12 +3237,17 @@ static int iscsit_build_sendtargets_response(struct iscsi_cmd *cmd)
                         spin_lock(&tpg->tpg_np_lock);
                         list_for_each_entry(tpg_np, &tpg->tpg_gnp_list,
                                                 tpg_np_list) {
+                                struct iscsi_np *np = tpg_np->tpg_np;
+                                bool inaddr_any = iscsit_check_inaddr_any(np);
+
                                 len = sprintf(buf, "TargetAddress="
                                         "%s%s%s:%hu,%hu",
-                                        (tpg_np->tpg_np->np_sockaddr.ss_family == AF_INET6) ?
-                                        "[" : "", tpg_np->tpg_np->np_ip,
-                                        (tpg_np->tpg_np->np_sockaddr.ss_family == AF_INET6) ?
-                                        "]" : "", tpg_np->tpg_np->np_port,
+                                        (np->np_sockaddr.ss_family == AF_INET6) ?
+                                        "[" : "", (inaddr_any == false) ?
+                                                np->np_ip : conn->local_ip,
+                                        (np->np_sockaddr.ss_family == AF_INET6) ?
+                                        "]" : "", (inaddr_any == false) ?
+                                                np->np_port : conn->local_port,
                                         tpg->tpgt);
                                 len += 1;
 
diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h
index ebf81fdbb5c5..0ec3b77a0c27 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -508,6 +508,7 @@ struct iscsi_conn {
         u16                     cid;
         /* Remote TCP Port */
         u16                     login_port;
+        u16                     local_port;
         int                     net_size;
         u32                     auth_id;
 #define CONNFLAG_SCTP_STRUCT_FILE                       0x01
@@ -527,6 +528,7 @@ struct iscsi_conn {
         unsigned char           bad_hdr[ISCSI_HDR_LEN];
 #define IPV6_ADDRESS_SPACE                              48
         unsigned char           login_ip[IPV6_ADDRESS_SPACE];
+        unsigned char           local_ip[IPV6_ADDRESS_SPACE];
         int                     conn_usage_count;
         int                     conn_waiting_on_uc;
         atomic_t                check_immediate_queue;
diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c
index 373b0cc6abd8..ec47a7c5966e 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -615,8 +615,8 @@ static int iscsi_post_login_handler(
                 }
 
                 pr_debug("iSCSI Login successful on CID: %hu from %s to"
-                        " %s:%hu,%hu\n", conn->cid, conn->login_ip, np->np_ip,
-                                np->np_port, tpg->tpgt);
+                        " %s:%hu,%hu\n", conn->cid, conn->login_ip,
+                        conn->local_ip, conn->local_port, tpg->tpgt);
 
                 list_add_tail(&conn->conn_list, &sess->sess_conn_list);
                 atomic_inc(&sess->nconn);
@@ -658,7 +658,8 @@ static int iscsi_post_login_handler(
         sess->session_state = TARG_SESS_STATE_LOGGED_IN;
 
         pr_debug("iSCSI Login successful on CID: %hu from %s to %s:%hu,%hu\n",
-                conn->cid, conn->login_ip, np->np_ip, np->np_port, tpg->tpgt);
+                conn->cid, conn->login_ip, conn->local_ip, conn->local_port,
+                tpg->tpgt);
 
         spin_lock_bh(&sess->conn_lock);
         list_add_tail(&conn->conn_list, &sess->sess_conn_list);
@@ -1020,6 +1021,18 @@ static int __iscsi_target_login_thread(struct iscsi_np *np)
                 snprintf(conn->login_ip, sizeof(conn->login_ip), "%pI6c",
                                 &sock_in6.sin6_addr.in6_u);
                 conn->login_port = ntohs(sock_in6.sin6_port);
+
+                if (conn->sock->ops->getname(conn->sock,
+                                (struct sockaddr *)&sock_in6, &err, 0) < 0) {
+                        pr_err("sock_ops->getname() failed.\n");
+                        iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+                                        ISCSI_LOGIN_STATUS_TARGET_ERROR);
+                        goto new_sess_out;
+                }
+                snprintf(conn->local_ip, sizeof(conn->local_ip), "%pI6c",
+                                &sock_in6.sin6_addr.in6_u);
+                conn->local_port = ntohs(sock_in6.sin6_port);
+
         } else {
                 memset(&sock_in, 0, sizeof(struct sockaddr_in));
 
@@ -1032,6 +1045,16 @@ static int __iscsi_target_login_thread(struct iscsi_np *np)
                 }
                 sprintf(conn->login_ip, "%pI4", &sock_in.sin_addr.s_addr);
                 conn->login_port = ntohs(sock_in.sin_port);
+
+                if (conn->sock->ops->getname(conn->sock,
+                                (struct sockaddr *)&sock_in, &err, 0) < 0) {
+                        pr_err("sock_ops->getname() failed.\n");
+                        iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+                                        ISCSI_LOGIN_STATUS_TARGET_ERROR);
+                        goto new_sess_out;
+                }
+                sprintf(conn->local_ip, "%pI4", &sock_in.sin_addr.s_addr);
+                conn->local_port = ntohs(sock_in.sin_port);
         }
 
         conn->network_transport = np->np_network_transport;
@@ -1039,7 +1062,7 @@ static int __iscsi_target_login_thread(struct iscsi_np *np)
         pr_debug("Received iSCSI login request from %s on %s Network"
                         " Portal %s:%hu\n", conn->login_ip,
                 (conn->network_transport == ISCSI_TCP) ? "TCP" : "SCTP",
-                        np->np_ip, np->np_port);
+                        conn->local_ip, conn->local_port);
 
         pr_debug("Moving to TARG_CONN_STATE_IN_LOGIN.\n");
         conn->conn_state        = TARG_CONN_STATE_IN_LOGIN;