unify error reporting

- introduce sys_error() and use it instead of perror() and
  error(strerror()) in all expected error conditions
- perror() is used only for "something's really wrong with the system"
  kind of errors
- file names, etc. are quoted if they are not validated yet, so e.g. an
  empty string becomes immediately obvious
- improve and unify language
- add missing newlines

TODO

@@ -15,8 +15,6 @@ quotas are weird, they make close() fail.
 
 clarify error cases of transactions.
 
-cleanup/improve error messages in the drivers.
-
 sync.c does not consider UID 0 valid, which is wrong. fixing this requires
 an incompatible change or a remapping hack in sync state files.
 

src/compat/config.c

@@ -97,7 +97,7 @@ load_config( const char *path, config_t ***stor )
 
 	if (!(fp = fopen( path, "r" ))) {
 		if (errno != ENOENT)
-			perror( "fopen" );
+			sys_error( "Cannot read config file '%s'", path );
 		return;
 	}
 	if (!Quiet && !Debug && !Verbose)

src/compat/convert.c

@@ -28,7 +28,6 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <sys/stat.h>
-#include <errno.h>
 #include <time.h>
 
 #include <db.h>
@@ -97,10 +96,9 @@ convert( config_t *box )
 	for (i = 0; i < 3; i++) {
 		nfsnprintf( buf, sizeof(buf), "%s/%s", mboxdir, subdirs[i] );
 		if (stat( buf, &sb )) {
-			fprintf( stderr, "ERROR: stat %s: %s (errno %d)\n", buf,
+			sys_error( "ERROR: cannot access %s", buf );
-			         strerror(errno), errno );
 			fprintf( stderr,
-			         "ERROR: %s does not appear to be a valid maildir style mailbox\n",
+			         "ERROR: '%s' does not appear to be a valid maildir style mailbox\n",
 			         mboxdir );
 			goto err1;
 		}
@@ -111,7 +109,7 @@ convert( config_t *box )
 	nfsnprintf( sname, sizeof(sname), "%s/.mbsyncstate", mboxdir );
 
 	if ((fd = open( ilname, O_WRONLY|O_CREAT, 0600 )) < 0) {
-		perror( ilname );
+		sys_error( "Cannot create %s", ilname );
 		goto err1;
 	}
 #if SEEK_SET != 0
@@ -121,20 +119,20 @@ convert( config_t *box )
 	lck.l_type = F_WRLCK;
 #endif
 	if (fcntl( fd, F_SETLKW, &lck )) {
-		perror( ilname );
+		sys_error( "Cannot lock %s", ilname );
 	  err2:
 		close( fd );
 		goto err1;
 	}
 
 	if (!(fp = fopen( iuvname, "r" ))) {
-		perror( iuvname );
+		sys_error( "Cannot open %s", iuvname );
 		goto err2;
 	}
 	fscanf( fp, "%d", &uidval );
 	fclose( fp );
 	if (!(fp = fopen( imuname, "r" ))) {
-		perror( imuname );
+		sys_error( "Cannot open %s", imuname );
 		goto err2;
 	}
 	fscanf( fp, "%d", &maxuid );
@@ -162,7 +160,7 @@ convert( config_t *box )
 	for (i = 0; i < 2; i++) {
 		nfsnprintf( buf, sizeof(buf), "%s/%s/", mboxdir, subdirs[i] );
 		if (!(d = opendir( buf ))) {
-			perror( "opendir" );
+			sys_error( "Cannot list %s", buf );
 		  err4:
 			free( msgs );
 			if (db)
@@ -199,7 +197,7 @@ convert( config_t *box )
 	qsort( msgs, nmsgs, sizeof(msg_t), compare_uids );
 
 	if (!(fp = fopen( sname, "w" ))) {
-		perror( sname );
+		sys_error( "Cannot create %s", sname );
 		goto err4;
 	}
 	if (box->max_messages) {
@@ -238,7 +236,7 @@ convert( config_t *box )
 		rename( iumname, diumname );
 	} else {
 		if (!(fp = fopen( uvname, "w" ))) {
-			perror( uvname );
+			sys_error( "Cannot create %s", uvname );
 			goto err4;
 		}
 		fprintf( fp, "%d\n%d\n", uidval, maxuid );

src/compat/isync.h

@@ -98,4 +98,5 @@ char *nfstrdup( const char *str );
 int nfvasprintf( char **str, const char *fmt, va_list va );
 int nfasprintf( char **str, const char *fmt, ... );
 int nfsnprintf( char *buf, int blen, const char *fmt, ... );
+void sys_error( const char *, ... );
 void ATTR_NORETURN oob( void );

src/compat/main.c

@@ -29,7 +29,6 @@
 #include <limits.h>
 #include <pwd.h>
 #include <stdio.h>
-#include <errno.h>
 #include <string.h>
 #include <ctype.h>
 #include <dirent.h>
@@ -336,7 +335,7 @@ main( int argc, char **argv )
 			struct dirent *de;
 
 			if (!(dir = opendir( xmaildir ))) {
-				fprintf( stderr, "%s: %s\n", xmaildir, strerror(errno) );
+				sys_error( "Cannot list '%s'", xmaildir );
 				return 1;
 			}
 			while ((de = readdir( dir ))) {
@@ -379,13 +378,13 @@ main( int argc, char **argv )
 			outconfig = path2;
 		}
 		if ((fd = creat( outconfig, 0666 )) < 0) {
-			fprintf( stderr, "Error: cannot write new config %s: %s\n", outconfig, strerror(errno) );
+			sys_error( "Error: cannot create config file '%s'", outconfig );
 			return 1;
 		}
 	} else {
 		strcpy( path2, "/tmp/mbsyncrcXXXXXX" );
 		if ((fd = mkstemp( path2 )) < 0) {
-			fprintf( stderr, "Can't create temp file\n" );
+			sys_error( "Error: cannot create temporary config file" );
 			return 1;
 		}
 	}
@@ -432,6 +431,6 @@ main( int argc, char **argv )
 				add_arg( &args, find_box( argv[optind] )->channel_name );
 	}
 	execvp( args[0], args );
-	perror( args[0] );
+	sys_error( "Cannot execute %s", args[0] );
 	return 1;
 }

src/compat/util.c

@@ -27,6 +27,19 @@
 #include <pwd.h>
 #include <ctype.h>
 
+void
+sys_error( const char *msg, ... )
+{
+	va_list va;
+	char buf[1024];
+
+	va_start( va, msg );
+	if ((unsigned)vsnprintf( buf, sizeof(buf), msg, va ) >= sizeof(buf))
+		oob();
+	va_end( va );
+	perror( buf );
+}
+
 char *
 next_arg( char **s )
 {

src/config.c

@@ -25,7 +25,6 @@
 
 #include <unistd.h>
 #include <limits.h>
-#include <errno.h>
 #include <pwd.h>
 #include <sys/types.h>
 #include <string.h>
@@ -272,7 +271,7 @@ load_config( const char *where, int pseudo )
 		info( "Reading configuration file %s\n", cfile.file );
 
 	if (!(cfile.fp = fopen( cfile.file, "r" ))) {
-		perror( "Cannot open config file" );
+		sys_error( "Cannot open config file '%s'", cfile.file );
 		return 1;
 	}
 	buf[sizeof(buf) - 1] = 0;

src/drv_imap.c

@@ -30,7 +30,6 @@
 #include <stdio.h>
 #include <stddef.h>
 #include <limits.h>
-#include <errno.h>
 #include <string.h>
 #include <ctype.h>
 
@@ -841,7 +840,7 @@ imap_socket_read( void *aux )
 		if (*arg == '*') {
 			arg = next_arg( &cmd );
 			if (!arg) {
-				error( "IMAP error: unable to parse untagged response\n" );
+				error( "IMAP error: malformed untagged response\n" );
 				break;
 			}
 
@@ -1838,8 +1837,8 @@ imap_parse_store( conffile_t *cfg, store_conf_t **storep, int *err )
 		else if (!strcasecmp( "CertificateFile", cfg->cmd )) {
 			server->sconf.cert_file = expand_strdup( cfg->val );
 			if (access( server->sconf.cert_file, R_OK )) {
-				error( "%s:%d: CertificateFile '%s': %s\n",
+				sys_error( "%s:%d: CertificateFile '%s'",
-				       cfg->file, cfg->line, server->sconf.cert_file, strerror( errno ) );
+				           cfg->file, cfg->line, server->sconf.cert_file );
 				*err = 1;
 			}
 		} else if (!strcasecmp( "RequireSSL", cfg->cmd ))

src/drv_maildir.c

@@ -101,7 +101,7 @@ maildir_open_store( store_conf_t *conf,
 	struct stat st;
 
 	if (stat( conf->path, &st ) || !S_ISDIR(st.st_mode)) {
-		error( "Maildir error: cannot open store %s\n", conf->path );
+		error( "Maildir error: cannot open store '%s'\n", conf->path );
 		cb( 0, aux );
 		return;
 	}
@@ -173,7 +173,7 @@ maildir_list( store_t *gctx,
 	struct dirent *de;
 
 	if (!(dir = opendir( gctx->conf->path ))) {
-		error( "%s: %s\n", gctx->conf->path, strerror(errno) );
+		sys_error( "Maildir error: cannot list %s", gctx->conf->path );
 		maildir_invoke_bad_callback( gctx );
 		cb( DRV_CANCELED, aux );
 		return;
@@ -240,16 +240,14 @@ maildir_validate( const char *prefix, const char *box, int create, maildir_store
 		if (errno == ENOENT) {
 			if (create) {
 				if (mkdir( buf, 0700 )) {
-					error( "Maildir error: mkdir %s: %s (errno %d)\n",
+					sys_error( "Maildir error: cannot create mailbox '%s'", buf );
-					       buf, strerror(errno), errno );
 					maildir_invoke_bad_callback( &ctx->gen );
 					return DRV_CANCELED;
 				}
 				for (i = 0; i < 3; i++) {
 					memcpy( buf + bl, subdirs[i], 4 );
 					if (mkdir( buf, 0700 )) {
-						error( "Maildir error: mkdir %s: %s (errno %d)\n",
+						sys_error( "Maildir error: cannot create directory %s", buf );
-						       buf, strerror(errno), errno );
 						return DRV_BOX_BAD;
 					}
 				}
@@ -258,8 +256,7 @@ maildir_validate( const char *prefix, const char *box, int create, maildir_store
 				return DRV_BOX_BAD;
 			}
 		} else {
-			error( "Maildir error: stat %s: %s (errno %d)\n",
+			sys_error( "Maildir error: cannot access mailbox '%s'", buf );
-			       buf, strerror(errno), errno );
 			return DRV_BOX_BAD;
 		}
 	} else {
@@ -273,8 +270,7 @@ maildir_validate( const char *prefix, const char *box, int create, maildir_store
 		memcpy( buf + bl, "tmp/", 5 );
 		bl += 4;
 		if (!(dirp = opendir( buf ))) {
-			error( "Maildir error: opendir: %s: %s (errno %d)\n",
+			sys_error( "Maildir error: cannot list %s", buf );
-			       buf, strerror(errno), errno );
 			return DRV_BOX_BAD;
 		}
 		time( &now );
@@ -282,16 +278,14 @@ maildir_validate( const char *prefix, const char *box, int create, maildir_store
 			nfsnprintf( buf + bl, sizeof(buf) - bl, "%s", entry->d_name );
 			if (stat( buf, &st )) {
 				if (errno != ENOENT)
-					error( "Maildir error: stat: %s: %s (errno %d)\n",
+					sys_error( "Maildir error: cannot access %s", buf );
-					       buf, strerror(errno), errno );
 			} else if (S_ISREG(st.st_mode) && now - st.st_ctime >= _24_HOURS) {
 				/* this should happen infrequently enough that it won't be
 				 * bothersome to the user to display when it occurs.
 				 */
 				info( "Maildir notice: removing stale file %s\n", buf );
 				if (unlink( buf ) && errno != ENOENT)
-					error( "Maildir error: unlink: %s: %s (errno %d)\n",
+					sys_error( "Maildir error: cannot remove %s", buf );
-					       buf, strerror(errno), errno );
 			}
 		}
 		closedir( dirp );
@@ -360,9 +354,8 @@ maildir_store_uid( maildir_store_t *ctx )
 }
 
 static int
-maildir_init_uid( maildir_store_t *ctx, const char *msg )
+maildir_init_uid( maildir_store_t *ctx )
 {
-	info( "Maildir notice: %s.\n", msg ? msg : "cannot read UIDVALIDITY, creating new" );
 	ctx->gen.uidvalidity = time( 0 );
 	ctx->nuid = 0;
 	ctx->uvok = 0;
@@ -376,6 +369,13 @@ maildir_init_uid( maildir_store_t *ctx, const char *msg )
 	return maildir_store_uid( ctx );
 }
 
+static int
+maildir_init_uid_new( maildir_store_t *ctx )
+{
+	info( "Maildir notice: no UIDVALIDITY, creating new.\n" );
+	return maildir_init_uid( ctx );
+}
+
 static int
 maildir_uidval_lock( maildir_store_t *ctx )
 {
@@ -402,7 +402,7 @@ maildir_uidval_lock( maildir_store_t *ctx )
 	lseek( ctx->uvfd, 0, SEEK_SET );
 	if ((n = read( ctx->uvfd, buf, sizeof(buf) )) <= 0 ||
 	    (buf[n] = 0, sscanf( buf, "%d\n%d", &ctx->gen.uidvalidity, &ctx->nuid ) != 2)) {
-		return maildir_init_uid( ctx, 0 );
+		return maildir_init_uid_new( ctx );
 	} else
 		ctx->uvok = 1;
 	return DRV_OK;
@@ -532,7 +532,7 @@ maildir_scan( maildir_store_t *ctx, msglist_t *msglist )
 		for (i = 0; i < 2; i++) {
 			memcpy( buf + bl, subdirs[i], 4 );
 			if (!(d = opendir( buf ))) {
-				perror( buf );
+				sys_error( "Maildir error: cannot list %s", buf );
 #ifdef USE_DB
 				if (!ctx->db)
 #endif /* USE_DB */
@@ -633,7 +633,8 @@ maildir_scan( maildir_store_t *ctx, msglist_t *msglist )
 			entry = &msglist->ents[i];
 			if (entry->uid != INT_MAX) {
 				if (uid == entry->uid) {
-					if ((ret = maildir_init_uid( ctx, "duplicate UID; changing UIDVALIDITY" )) != DRV_OK) {
+					info( "Maildir notice: duplicate UID; changing UIDVALIDITY.\n");
+					if ((ret = maildir_init_uid( ctx )) != DRV_OK) {
 						maildir_free_scan( msglist );
 						return ret;
 					}
@@ -670,13 +671,14 @@ maildir_scan( maildir_store_t *ctx, msglist_t *msglist )
 				memcpy( nbuf, buf, bl + 4 );
 				nfsnprintf( nbuf + bl + 4, sizeof(nbuf) - bl - 4, "%s", entry->base );
 				if (rename( nbuf, buf )) {
-				  notok:
 					if (errno != ENOENT) {
-						perror( buf );
+						sys_error( "Maildir error: cannot rename %s to %s", nbuf, buf );
+					  fail:
 						maildir_uidval_unlock( ctx );
 						maildir_free_scan( msglist );
 						return DRV_BOX_BAD;
 					}
+				  retry:
 					maildir_free_scan( msglist );
 					goto again;
 				}
@@ -685,13 +687,23 @@ maildir_scan( maildir_store_t *ctx, msglist_t *msglist )
 				memcpy( entry->base, buf + bl + 4, fnl );
 			}
 			if (ctx->gen.opts & OPEN_SIZE) {
-				if (stat( buf, &st ))
+				if (stat( buf, &st )) {
-					goto notok;
+					if (errno != ENOENT) {
+						sys_error( "Maildir error: cannot stat %s", buf );
+						goto fail;
+					}
+					goto retry;
+				}
 				entry->size = st.st_size;
 			}
 			if (ctx->gen.opts & OPEN_FIND) {
-				if (!(f = fopen( buf, "r" )))
+				if (!(f = fopen( buf, "r" ))) {
-					goto notok;
+					if (errno != ENOENT) {
+						sys_error( "Maildir error: cannot open %s", buf );
+						goto fail;
+					}
+					goto retry;
+				}
 				while (fgets( nbuf, sizeof(nbuf), f )) {
 					if (!nbuf[0] || nbuf[0] == '\n')
 						break;
@@ -767,7 +779,7 @@ maildir_select( store_t *gctx, int create,
 	nfsnprintf( uvpath, sizeof(uvpath), "%s/.uidvalidity", gctx->path );
 #ifndef USE_DB
 	if ((ctx->uvfd = open( uvpath, O_RDWR|O_CREAT, 0600 )) < 0) {
-		perror( uvpath );
+		sys_error( "Maildir error: cannot write %s", uvpath );
 		cb( DRV_BOX_BAD, aux );
 		return;
 	}
@@ -783,7 +795,7 @@ maildir_select( store_t *gctx, int create,
 				if ((ctx->uvfd = open( uvpath, O_RDWR|O_CREAT, 0600 )) >= 0)
 					goto fnok;
 			}
-			perror( uvpath );
+			sys_error( "Maildir error: cannot write %s", uvpath );
 			cb( DRV_BOX_BAD, aux );
 			return;
 		}
@@ -793,7 +805,7 @@ maildir_select( store_t *gctx, int create,
 #endif
 		lck.l_type = F_WRLCK;
 		if (fcntl( ctx->uvfd, F_SETLKW, &lck )) {
-			perror( uvpath );
+			sys_error( "Maildir error: cannot lock %s", uvpath );
 		  bork:
 			close( ctx->uvfd );
 			ctx->uvfd = -1;
@@ -817,7 +829,7 @@ maildir_select( store_t *gctx, int create,
 				ctx->db->err( ctx->db, ret, "Maildir error: db->get()" );
 				goto dbork;
 			}
-			if (maildir_init_uid( ctx, 0 ) != DRV_OK)
+			if (maildir_init_uid_new( ctx ) != DRV_OK)
 				goto dbork;
 		} else {
 			ctx->gen.uidvalidity = ((int *)value.data)[0];
@@ -926,12 +938,13 @@ maildir_rescan( maildir_store_t *ctx )
 }
 
 static int
-maildir_again( maildir_store_t *ctx, maildir_message_t *msg, const char *fn )
+maildir_again( maildir_store_t *ctx, maildir_message_t *msg,
+               const char *err, const char *fn, const char *fn2 )
 {
 	int ret;
 
 	if (errno != ENOENT) {
-		perror( fn );
+		sys_error( err, fn, fn2 );
 		return DRV_BOX_BAD;
 	}
 	if ((ret = maildir_rescan( ctx )) != DRV_OK)
@@ -953,7 +966,7 @@ maildir_fetch_msg( store_t *gctx, message_t *gmsg, msg_data_t *data,
 		nfsnprintf( buf, sizeof(buf), "%s/%s/%s", gctx->path, subdirs[gmsg->status & M_RECENT], msg->base );
 		if ((fd = open( buf, O_RDONLY )) >= 0)
 			break;
-		if ((ret = maildir_again( ctx, msg, buf )) != DRV_OK) {
+		if ((ret = maildir_again( ctx, msg, "Cannot open %s", buf, 0 )) != DRV_OK) {
 			cb( ret, aux );
 			return;
 		}
@@ -962,7 +975,7 @@ maildir_fetch_msg( store_t *gctx, message_t *gmsg, msg_data_t *data,
 	data->len = st.st_size;
 	data->data = nfmalloc( data->len );
 	if (read( fd, data->data, data->len ) != data->len) {
-		perror( buf );
+		sys_error( "Maildir error: cannot read %s", buf );
 		close( fd );
 		cb( DRV_MSG_BAD, aux );
 		return;
@@ -1028,7 +1041,7 @@ maildir_store_msg( store_t *gctx, msg_data_t *data, int to_trash,
 	nfsnprintf( buf, sizeof(buf), "%s%s/tmp/%s%s", prefix, box, base, fbuf );
 	if ((fd = open( buf, O_WRONLY|O_CREAT|O_EXCL, 0600 )) < 0) {
 		if (errno != ENOENT) {
-			perror( buf );
+			sys_error( "Maildir error: cannot create %s", buf );
 			free( data->data );
 			cb( DRV_BOX_BAD, 0, aux );
 			return;
@@ -1039,7 +1052,7 @@ maildir_store_msg( store_t *gctx, msg_data_t *data, int to_trash,
 			return;
 		}
 		if ((fd = open( buf, O_WRONLY|O_CREAT|O_EXCL, 0600 )) < 0) {
-			perror( buf );
+			sys_error( "Maildir error: cannot create %s", buf );
 			free( data->data );
 			cb( DRV_BOX_BAD, 0, aux );
 			return;
@@ -1049,23 +1062,23 @@ maildir_store_msg( store_t *gctx, msg_data_t *data, int to_trash,
 	free( data->data );
 	if (ret != data->len) {
 		if (ret < 0)
-			perror( buf );
+			sys_error( "Maildir error: cannot write %s", buf );
 		else
-			error( "Maildir error: %s: partial write\n", buf );
+			error( "Maildir error: cannot write %s. Disk full?\n", buf );
 		close( fd );
 		cb( DRV_BOX_BAD, 0, aux );
 		return;
 	}
 	if (close( fd ) < 0) {
 		/* Quota exceeded may cause this. */
-		perror( buf );
+		sys_error( "Maildir error: cannot write %s", buf );
 		cb( DRV_BOX_BAD, 0, aux );
 		return;
 	}
 	/* Moving seen messages to cur/ is strictly speaking incorrect, but makes mutt happy. */
 	nfsnprintf( nbuf, sizeof(nbuf), "%s%s/%s/%s%s", prefix, box, subdirs[!(data->flags & F_SEEN)], base, fbuf );
 	if (rename( buf, nbuf )) {
-		perror( nbuf );
+		sys_error( "Maildir error: cannot rename %s to %s", buf, nbuf );
 		cb( DRV_BOX_BAD, 0, aux );
 		return;
 	}
@@ -1131,7 +1144,7 @@ maildir_set_flags( store_t *gctx, message_t *gmsg, int uid, int add, int del,
 		}
 		if (!rename( buf, nbuf ))
 			break;
-		if ((ret = maildir_again( ctx, msg, buf )) != DRV_OK) {
+		if ((ret = maildir_again( ctx, msg, "Maildir error: cannot rename %s to %s", buf, nbuf )) != DRV_OK) {
 			cb( ret, aux );
 			return;
 		}
@@ -1189,12 +1202,12 @@ maildir_trash_msg( store_t *gctx, message_t *gmsg,
 			if (!rename( buf, nbuf ))
 				break;
 			if (errno != ENOENT) {
-				perror( nbuf );
+				sys_error( "Maildir error: cannot move %s to %s", buf, nbuf );
 				cb( DRV_BOX_BAD, aux );
 				return;
 			}
 		}
-		if ((ret = maildir_again( ctx, msg, buf )) != DRV_OK) {
+		if ((ret = maildir_again( ctx, msg, "Maildir error: cannot move %s to %s", buf, nbuf )) != DRV_OK) {
 			cb( ret, aux );
 			return;
 		}
@@ -1232,7 +1245,7 @@ maildir_close( store_t *gctx,
 					if (errno == ENOENT)
 						retry = 1;
 					else
-						perror( buf );
+						sys_error( "Maildir error: cannot remove %s", buf );
 				} else {
 					msg->status |= M_DEAD;
 					gctx->count--;

src/isync.h

@@ -83,6 +83,7 @@ typedef struct {
 	int fd;
 	int state;
 	const server_conf_t *conf; /* needed during connect */
+	char *name;
 #ifdef HAVE_LIBSSL
 	SSL *ssl;
 #endif
@@ -366,6 +367,7 @@ static INLINE void socket_init( conn_t *conn,
 	conn->write_callback = write_callback;
 	conn->callback_aux = aux;
 	conn->fd = -1;
+	conn->name = 0;
 	conn->write_buf_append = &conn->write_buf;
 }
 void socket_connect( conn_t *conn, void (*cb)( int ok, void *aux ) );
@@ -397,6 +399,7 @@ void info( const char *, ... );
 void infon( const char *, ... );
 void warn( const char *, ... );
 void error( const char *, ... );
+void sys_error( const char *, ... );
 
 char *next_arg( char ** );
 

src/mdconvert.c

@@ -35,6 +35,32 @@
 
 #define EXE "mdconvert"
 
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
+# define ATTR_NORETURN __attribute__((noreturn))
+#else
+# define ATTR_NORETURN
+#endif
+
+static void ATTR_NORETURN
+oob( void )
+{
+	fputs( "Fatal: buffer too small. Please report a bug.\n", stderr );
+	abort();
+}
+
+static void
+sys_error( const char *msg, ... )
+{
+	va_list va;
+	char buf[1024];
+
+	va_start( va, msg );
+	if ((unsigned)vsnprintf( buf, sizeof(buf), msg, va ) >= sizeof(buf))
+		oob();
+	va_end( va );
+	perror( buf );
+}
+
 static int
 nfsnprintf( char *buf, int blen, const char *fmt, ... )
 {
@@ -42,10 +68,8 @@ nfsnprintf( char *buf, int blen, const char *fmt, ... )
 	va_list va;
 
 	va_start( va, fmt );
-	if (blen <= 0 || (unsigned)(ret = vsnprintf( buf, blen, fmt, va )) >= (unsigned)blen) {
+	if (blen <= 0 || (unsigned)(ret = vsnprintf( buf, blen, fmt, va )) >= (unsigned)blen)
-		fputs( "Fatal: buffer too small. Please report a bug.\n", stderr );
+		oob();
-		abort();
-	}
 	va_end( va );
 	return ret;
 }
@@ -81,15 +105,15 @@ convert( const char *box, int altmap )
 	nfsnprintf( tdpath, sizeof(tdpath), "%s.tmp", dpath );
 	if ((sfd = open( spath, O_RDWR )) < 0) {
 		if (errno != ENOENT)
-			perror( spath );
+			sys_error( "Cannot open %s", spath );
 		return 1;
 	}
 	if (fcntl( sfd, F_SETLKW, &lck )) {
-		perror( spath );
+		sys_error( "Cannot lock %s", spath );
 		goto sbork;
 	}
 	if ((dfd = open( tdpath, O_RDWR|O_CREAT, 0600 )) < 0) {
-		perror( tdpath );
+		sys_error( "Cannot create %s", tdpath );
 		goto sbork;
 	}
 	if (db_create( &db, 0, 0 )) {
@@ -138,7 +162,7 @@ convert( const char *box, int altmap )
 	for (i = 0; i < 2; i++) {
 		bl = nfsnprintf( buf, sizeof(buf), "%s/%s/", box, subdirs[i] );
 		if (!(d = opendir( buf ))) {
-			perror( "opendir" );
+			sys_error( "Cannot list %s", buf );
 			goto dbork;
 		}
 		while ((e = readdir( d ))) {
@@ -185,7 +209,7 @@ convert( const char *box, int altmap )
 			if (rename( buf, buf2 )) {
 				if (errno == ENOENT)
 					goto again;
-				perror( buf );
+				sys_error( "Cannot rename %s to %s", buf, buf2 );
 			  ebork:
 				closedir( d );
 				goto dbork;
@@ -198,11 +222,11 @@ convert( const char *box, int altmap )
 	db->close( db, 0 );
 	close( dfd );
 	if (rename( tdpath, dpath )) {
-		perror( dpath );
+		sys_error( "Cannot rename %s to %s", tdpath, dpath );
 		return 1;
 	}
 	if (unlink( spath ))
-		perror( spath );
+		sys_error( "Cannot remove %s", spath );
 	close( sfd );
 	return 0;
 }

src/socket.c

@@ -79,15 +79,15 @@ ssl_return( const char *func, conn_t *conn, int ret )
 	case SSL_ERROR_SSL:
 		if (!(err = ERR_get_error())) {
 			if (ret == 0)
-				error( "SSL_%s: unexpected EOF\n", func );
+				error( "Socket error: secure %s %s: unexpected EOF\n", func, conn->name );
 			else
-				error( "SSL_%s: %s\n", func, strerror( errno ) );
+				sys_error( "Socket error: secure %s %s", func, conn->name );
 		} else {
-			error( "SSL_%s: %s\n", func, ERR_error_string( err, 0 ) );
+			error( "Socket error: secure %s %s: %s\n", func, conn->name, ERR_error_string( err, 0 ) );
 		}
 		break;
 	default:
-		error( "SSL_%s: unhandled SSL error %d\n", func, err );
+		error( "Socket error: secure %s %s: unhandled SSL error %d\n", func, conn->name, err );
 		break;
 	}
 	if (conn->state == SCK_STARTTLS)
@@ -148,11 +148,11 @@ verify_cert( const server_conf_t *conf, conn_t *sock )
 
 	while (conf->cert_file) { /* while() instead of if() so break works */
 		if (X509_cmp_current_time( X509_get_notBefore( cert )) >= 0) {
-			error( "Server certificate is not yet valid" );
+			error( "Server certificate is not yet valid\n" );
 			break;
 		}
 		if (X509_cmp_current_time( X509_get_notAfter( cert )) <= 0) {
-			error( "Server certificate has expired" );
+			error( "Server certificate has expired\n" );
 			break;
 		}
 		if (!X509_digest( cert, EVP_sha1(), md, &n )) {
@@ -160,8 +160,7 @@ verify_cert( const server_conf_t *conf, conn_t *sock )
 			break;
 		}
 		if (!(fp = fopen( conf->cert_file, "rt" ))) {
-			error( "Unable to load CertificateFile '%s': %s\n",
+			sys_error( "Unable to load CertificateFile '%s'", conf->cert_file );
-			       conf->cert_file, strerror( errno ) );
 			return -1;
 		}
 		err = -1;
@@ -197,7 +196,7 @@ verify_cert( const server_conf_t *conf, conn_t *sock )
 	X509_STORE_CTX_cleanup( &xsc );
 	if (!err)
 		return 0;
-	error( "Error, can't verify certificate: %s (%d)\n",
+	error( "Error, cannot verify certificate: %s (%d)\n",
 	       X509_verify_cert_error_string( err ), err );
 
 	X509_NAME_oneline( X509_get_subject_name( cert ), buf, sizeof(buf) );
@@ -286,7 +285,7 @@ socket_start_tls( conn_t *conn, void (*cb)( int ok, void *aux ) )
 static void
 start_tls_p2( conn_t *conn )
 {
-	switch (ssl_return( "connect", conn, SSL_connect( conn->ssl ) )) {
+	switch (ssl_return( "connect to", conn, SSL_connect( conn->ssl ) )) {
 	case -1:
 		start_tls_p3( conn, 0 );
 		break;
@@ -337,7 +336,8 @@ socket_connect( conn_t *sock, void (*cb)( int ok, void *aux ) )
 
 	/* open connection to IMAP server */
 	if (conf->tunnel) {
-		infon( "Starting tunnel '%s'... ", conf->tunnel );
+		nfasprintf( &sock->name, "tunnel '%s'", conf->tunnel );
+		infon( "Starting %s... ", sock->name );
 
 		if (socketpair( PF_UNIX, SOCK_STREAM, 0, a )) {
 			perror( "socketpair" );
@@ -387,11 +387,12 @@ socket_connect( conn_t *sock, void (*cb)( int ok, void *aux ) )
 		fcntl( s, F_SETFL, O_NONBLOCK );
 		add_fd( s, socket_fd_cb, sock );
 
-		infon( "Connecting to %s (%s:%hu) ... ",
+		nfasprintf( &sock->name, "%s (%s:%hu)",
-		       conf->host, inet_ntoa( addr.sin_addr ), ntohs( addr.sin_port ) );
+		            conf->host, inet_ntoa( addr.sin_addr ), ntohs( addr.sin_port ) );
+		infon( "Connecting to %s... ", sock->name );
 		if (connect( s, (struct sockaddr *)&addr, sizeof(addr) )) {
 			if (errno != EINPROGRESS) {
-				perror( "connect" );
+				sys_error( "Cannot connect to %s", sock->name );
 				socket_close_internal( sock );
 				goto bail;
 			}
@@ -416,19 +417,17 @@ socket_connected( conn_t *conn )
 	int soerr;
 	socklen_t selen = sizeof(soerr);
 
-	infon( "Connecting to %s: ", conn->conf->host );
 	if (getsockopt( conn->fd, SOL_SOCKET, SO_ERROR, &soerr, &selen )) {
 		perror( "getsockopt" );
 		exit( 1 );
 	}
 	if (soerr) {
 		errno = soerr;
-		perror( "connect" );
+		sys_error( "Cannot connect to %s", conn->name );
 		socket_close_internal( conn );
 		socket_connect_bail( conn );
 		return;
 	}
-	info( "ok\n" );
 	socket_connected2( conn );
 }
 
@@ -443,6 +442,8 @@ socket_connected2( conn_t *conn )
 static void
 socket_connect_bail( conn_t *conn )
 {
+	free( conn->name );
+	conn->name = 0;
 	conn->callbacks.connect( 0, conn->callback_aux );
 }
 
@@ -453,6 +454,8 @@ socket_close( conn_t *sock )
 {
 	if (sock->fd >= 0)
 		socket_close_internal( sock );
+	free( sock->name );
+	sock->name = 0;
 #ifdef HAVE_LIBSSL
 	if (sock->ssl) {
 		SSL_free( sock->ssl );
@@ -478,7 +481,7 @@ socket_fill( conn_t *sock )
 	buf = sock->buf + n;
 #ifdef HAVE_LIBSSL
 	if (sock->ssl) {
-		if ((n = ssl_return( "read", sock, SSL_read( sock->ssl, buf, len ) )) <= 0)
+		if ((n = ssl_return( "read from", sock, SSL_read( sock->ssl, buf, len ) )) <= 0)
 			return;
 		if (n == len && SSL_pending( sock->ssl ))
 			fake_fd( sock->fd, POLLIN );
@@ -486,11 +489,11 @@ socket_fill( conn_t *sock )
 #endif
 	{
 		if ((n = read( sock->fd, buf, len )) < 0) {
-			perror( "read" );
+			sys_error( "Socket error: read from %s", sock->name );
 			socket_fail( sock );
 			return;
 		} else if (!n) {
-			error( "read: unexpected EOF\n" );
+			error( "Socket error: read from %s: unexpected EOF\n", sock->name );
 			socket_fail( sock );
 			return;
 		}
@@ -549,12 +552,12 @@ do_write( conn_t *sock, char *buf, int len )
 	assert( sock->fd >= 0 );
 #ifdef HAVE_LIBSSL
 	if (sock->ssl)
-		return ssl_return( "write", sock, SSL_write( sock->ssl, buf, len ) );
+		return ssl_return( "write to", sock, SSL_write( sock->ssl, buf, len ) );
 #endif
 	n = write( sock->fd, buf, len );
 	if (n < 0) {
 		if (errno != EAGAIN && errno != EWOULDBLOCK) {
-			perror( "write" );
+			sys_error( "Socket error: write to %s", sock->name );
 			socket_fail( sock );
 		} else {
 			n = 0;
@@ -646,7 +649,7 @@ socket_fd_cb( int events, void *aux )
 	conn_t *conn = (conn_t *)aux;
 
 	if (events & POLLERR) {
-		error( "Unidentified socket error.\n" );
+		error( "Unidentified socket error from %s.\n", conn->name );
 		socket_fail( conn );
 		return;
 	}

src/sync.c

@@ -40,7 +40,7 @@ void
 Fclose( FILE *f )
 {
 	if (fclose( f ) == EOF) {
-		perror( "cannot close file" );
+		sys_error( "Error: cannot close file. Disk full?" );
 		exit( 1 );
 	}
 }
@@ -55,7 +55,7 @@ Fprintf( FILE *f, const char *msg, ... )
 	r = vfprintf( f, msg, va );
 	va_end( va );
 	if (r < 0) {
-		perror( "cannot write file" );
+		sys_error( "Error: cannot write file. Disk full?" );
 		exit( 1 );
 	}
 }
@@ -624,12 +624,12 @@ box_selected( int sts, void *aux )
 		}
 		free( csname );
 		if (!(s = strrchr( svars->dname, '/' ))) {
-			error( "Error: invalid SyncState '%s'\n", svars->dname );
+			error( "Error: invalid SyncState location '%s'\n", svars->dname );
 			goto sbail;
 		}
 		*s = 0;
 		if (mkdir( svars->dname, 0700 ) && errno != EEXIST) {
-			error( "Error: cannot create SyncState directory '%s': %s\n", svars->dname, strerror(errno) );
+			sys_error( "Error: cannot create SyncState directory '%s'", svars->dname );
 			goto sbail;
 		}
 		*s = '/';
@@ -645,7 +645,7 @@ box_selected( int sts, void *aux )
 	lck.l_type = F_WRLCK;
 #endif
 	if ((svars->lfd = open( svars->lname, O_WRONLY|O_CREAT, 0666 )) < 0) {
-		error( "Error: cannot create lock file %s: %s\n", svars->lname, strerror(errno) );
+		sys_error( "Error: cannot create lock file %s", svars->lname );
 		svars->ret = SYNC_FAIL;
 		sync_bail2( svars );
 		return;

src/util.c

@@ -120,6 +120,23 @@ error( const char *msg, ... )
 	va_end( va );
 }
 
+void
+sys_error( const char *msg, ... )
+{
+	va_list va;
+	char buf[1024];
+
+	if (need_nl) {
+		putchar( '\n' );
+		need_nl = 0;
+	}
+	va_start( va, msg );
+	if ((unsigned)vsnprintf( buf, sizeof(buf), msg, va ) >= sizeof(buf))
+		oob();
+	va_end( va );
+	perror( buf );
+}
+
 char *
 next_arg( char **s )
 {