Write error message to syslog when add user failed or connect to TACACS server failed. (#16240) (#17081)

Write error message to syslog when add user failed or connect to TACACS server failed.

Why I did it
With these messages, we can downgrade TACACS server with issue to lower priority.

Work item tracking
Microsoft ADO: 24667696
How I did it
Write error message to syslog when add user failed or connect to TACACS server failed.

How to verify it
Pass all UT.
Manually verify error message generated.

src/tacacs/nss/patch/0001-Modify-user-map-profile.patch

@@ -18,9 +18,9 @@ Subject: [PATCH] Modify user map profile
  debian/changelog              |   11 +
  debian/control                |   11 +-
  debian/libnss-tacplus.symbols |    1 -
- nss_tacplus.c                 | 1018 +++++++++++++++------------------
+ nss_tacplus.c                 | 1015 +++++++++++++++------------------
  tacplus_nss.conf              |   91 ++-
- 8 files changed, 527 insertions(+), 613 deletions(-)
+ 8 files changed, 525 insertions(+), 612 deletions(-)
 
 diff --git a/Makefile.am b/Makefile.am
 index 293951e..b33c455 100644
@@ -1083,7 +1083,7 @@ index 79e62b9..ecfa0b0 100644
          tac_add_attrib(attr, "service", tac_service);
          if(tac_protocol[0])
              tac_add_attrib(attr, "protocol", tac_protocol);
-@@ -598,34 +659,9 @@ lookup_tacacs_user(struct pwbuf *pb)
+@@ -598,52 +659,25 @@ lookup_tacacs_user(struct pwbuf *pb)
  {
      struct areply arep;
      int ret = 1, done = 0;
@@ -1119,11 +1119,17 @@ index 79e62b9..ecfa0b0 100644
      for(srvr=0; srvr < tac_srv_no && !done; srvr++) {
          arep.msg = NULL;
          arep.attr = NULL;
-@@ -636,14 +672,13 @@ lookup_tacacs_user(struct pwbuf *pb)
+         arep.status = TAC_PLUS_AUTHOR_STATUS_ERROR; /* if author_send fails */
-                 syslog(LOG_WARNING, "%s: failed to connect TACACS+ server %s,"
+         tac_fd = connect_tacacs(&attr, srvr);
-                     " ret=%d: %m", nssname, tac_srv[srvr].addr ?
+         if (tac_fd < 0) {
-                     tac_ntop(tac_srv[srvr].addr->ai_addr) : "unknown", tac_fd);
+-            if(debug)
+-                syslog(LOG_WARNING, "%s: failed to connect TACACS+ server %s,"
+-                    " ret=%d: %m", nssname, tac_srv[srvr].addr ?
+-                    tac_ntop(tac_srv[srvr].addr->ai_addr) : "unknown", tac_fd);
 -            tac_free_attrib(&attr);
++            syslog(LOG_ERR, "%s: failed to connect TACACS+ server %s,"
++                " ret=%d: %m", nssname, tac_srv[srvr].addr ?
++                tac_ntop(tac_srv[srvr].addr->ai_addr) : "unknown", tac_fd);
              continue;
          }
 -        ret = tac_author_send(tac_fd, pb->name, "", tac_rhost, attr);
@@ -1137,7 +1143,7 @@ index 79e62b9..ecfa0b0 100644
                      tac_ntop(tac_srv[srvr].addr->ai_addr) : "unknown", ret,
                      pb->name);
          }
-@@ -668,14 +703,11 @@ lookup_tacacs_user(struct pwbuf *pb)
+@@ -668,14 +702,11 @@ lookup_tacacs_user(struct pwbuf *pb)
          if(arep.status == AUTHOR_STATUS_PASS_ADD ||
             arep.status == AUTHOR_STATUS_PASS_REPL) {
              ret = got_tacacs_user(arep.attr, pb);
@@ -1154,7 +1160,7 @@ index 79e62b9..ecfa0b0 100644
              done = 1; /* break out of loop after arep cleanup */
          }
          else {
-@@ -685,6 +717,10 @@ lookup_tacacs_user(struct pwbuf *pb)
+@@ -685,6 +716,10 @@ lookup_tacacs_user(struct pwbuf *pb)
                      " invalid (%d)", nssname,
                      tac_ntop(tac_srv[srvr].addr->ai_addr), pb->name,
                      arep.status);
@@ -1165,7 +1171,7 @@ index 79e62b9..ecfa0b0 100644
          }
          if(arep.msg)
              free(arep.msg);
-@@ -692,30 +728,12 @@ lookup_tacacs_user(struct pwbuf *pb)
+@@ -692,30 +727,12 @@ lookup_tacacs_user(struct pwbuf *pb)
              tac_free_attrib(&arep.attr);
      }
  
@@ -1198,7 +1204,7 @@ index 79e62b9..ecfa0b0 100644
   *
   * We try the lookup to the tacacs server first.  If we can't make a
   * connection to the server for some reason, we also try looking up
-@@ -730,20 +748,25 @@ enum nss_status _nss_tacplus_getpwnam_r(const char *name, struct passwd *pw,
+@@ -730,20 +747,25 @@ enum nss_status _nss_tacplus_getpwnam_r(const char *name, struct passwd *pw,
      int result;
      struct pwbuf pbuf;
  
@@ -1233,7 +1239,7 @@ index 79e62b9..ecfa0b0 100644
          /* marshal the args for the lower level functions */
          pbuf.name = (char *)name;
          pbuf.pw = pw;
-@@ -751,126 +774,13 @@ enum nss_status _nss_tacplus_getpwnam_r(const char *name, struct passwd *pw,
+@@ -751,126 +773,13 @@ enum nss_status _nss_tacplus_getpwnam_r(const char *name, struct passwd *pw,
          pbuf.buflen = buflen;
          pbuf.errnop = errnop;
  
@@ -1468,4 +1474,3 @@ index bb4eb1e..7cb756f 100644
 +# many_to_one=y
 -- 
 2.7.4
-

src/tacacs/nss/patch/0010-Send-remote-address-in-TACACS-authorization-message.patch

@@ -113,8 +113,8 @@ index 2de00a6..048745a 100644
  
      for(srvr=0; srvr < tac_srv_no && !done; srvr++) {
          arep.msg = NULL;
-@@ -748,7 +823,7 @@ lookup_tacacs_user(struct pwbuf *pb)
+@@ -747,7 +822,7 @@ lookup_tacacs_user(struct pwbuf *pb)
-                     tac_ntop(tac_srv[srvr].addr->ai_addr) : "unknown", tac_fd);
+                 tac_ntop(tac_srv[srvr].addr->ai_addr) : "unknown", tac_fd);
              continue;
          }
 -        ret = tac_author_send(tac_fd, pb->name, "", "", attr);