# HG changeset patch
# User Kevin Darbyshire-Bryant <6500011+ldir-EDB0@users.noreply.github.com>
# Date 1584545336 0
# Node ID 7c17995bcdfb4797963960578889f730ff9dff28
# Parent  871484eac157718776698e836f6687ba6883de6b
Improve address logging on early exit messages (#83)

Change 'Early exit' and 'Exit before auth' messages to include the IP
address & port as part of the message.

This allows log scanning utilities such as 'fail2ban' to obtain the
offending IP address as part of the failure event instead of extracting
the PID from the message and then scanning the log again for match
'child connection from' messages

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>

diff -r 871484eac157 -r 7c17995bcdfb svr-auth.c
--- a/svr-auth.c	Sat Mar 14 23:33:30 2020 +0800
+++ b/svr-auth.c	Wed Mar 18 15:28:56 2020 +0000
@@ -241,8 +241,7 @@
 	}
 
 	if (strlen(username) != userlen) {
-		dropbear_exit("Attempted username with a null byte from %s",
-			svr_ses.addrstring);
+		dropbear_exit("Attempted username with a null byte");
 	}
 
 	if (ses.authstate.username == NULL) {
@@ -252,8 +251,7 @@
 	} else {
 		/* check username hasn't changed */
 		if (strcmp(username, ses.authstate.username) != 0) {
-			dropbear_exit("Client trying multiple usernames from %s",
-				svr_ses.addrstring);
+			dropbear_exit("Client trying multiple usernames");
 		}
 	}
 
@@ -268,8 +266,7 @@
 	if (!ses.authstate.pw_name) {
 		TRACE(("leave checkusername: user '%s' doesn't exist", username))
 		dropbear_log(LOG_WARNING,
-				"Login attempt for nonexistent user from %s",
-				svr_ses.addrstring);
+				"Login attempt for nonexistent user");
 		ses.authstate.checkusername_failed = 1;
 		return DROPBEAR_FAILURE;
 	}
@@ -279,9 +276,8 @@
 	if (!(DROPBEAR_SVR_MULTIUSER && uid == 0) && uid != ses.authstate.pw_uid) {
 		TRACE(("running as nonroot, only server uid is allowed"))
 		dropbear_log(LOG_WARNING,
-				"Login attempt with wrong user %s from %s",
-				ses.authstate.pw_name,
-				svr_ses.addrstring);
+				"Login attempt with wrong user %s",
+				ses.authstate.pw_name);
 		ses.authstate.checkusername_failed = 1;
 		return DROPBEAR_FAILURE;
 	}
@@ -440,8 +436,8 @@
 		} else {
 			userstr = ses.authstate.pw_name;
 		}
-		dropbear_exit("Max auth tries reached - user '%s' from %s",
-				userstr, svr_ses.addrstring);
+		dropbear_exit("Max auth tries reached - user '%s'",
+				userstr);
 	}
 	
 	TRACE(("leave send_msg_userauth_failure"))
diff -r 871484eac157 -r 7c17995bcdfb svr-session.c
--- a/svr-session.c	Sat Mar 14 23:33:30 2020 +0800
+++ b/svr-session.c	Wed Mar 18 15:28:56 2020 +0000
@@ -222,7 +222,7 @@
 	/* Add the prefix depending on session/auth state */
 	if (!ses.init_done) {
 		/* before session init */
-		snprintf(fullmsg, sizeof(fullmsg), "Early exit: %s", exitmsg);
+		snprintf(fullmsg, sizeof(fullmsg), "Early exit from <%s> %s", svr_ses.addrstring, exitmsg);
 	} else if (ses.authstate.authdone) {
 		/* user has authenticated */
 		snprintf(fullmsg, sizeof(fullmsg),
@@ -231,11 +231,11 @@
 	} else if (ses.authstate.pw_name) {
 		/* we have a potential user */
 		snprintf(fullmsg, sizeof(fullmsg), 
-				"Exit before auth (user '%s', %u fails): %s",
-				ses.authstate.pw_name, ses.authstate.failcount, exitmsg);
+				"Exit before auth from <%s> (user '%s', %u fails): %s",
+				svr_ses.addrstring, ses.authstate.pw_name, ses.authstate.failcount, exitmsg);
 	} else {
 		/* before userauth */
-		snprintf(fullmsg, sizeof(fullmsg), "Exit before auth: %s", exitmsg);
+		snprintf(fullmsg, sizeof(fullmsg), "Exit before auth from <%s> %s", svr_ses.addrstring, exitmsg);
 	}
 
 	dropbear_log(LOG_INFO, "%s", fullmsg);