X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/7a24c346b07d672c3d95bb44f16a0133f5197e3d..7df0935a5124dbe1ce81f3b462645464bd17aa9d:/io.c

diff --git a/io.c b/io.c
index 253344b0..a451c133 100644
--- a/io.c
+++ b/io.c
@@ -1,7 +1,8 @@
 /* -*- c-file-style: "linux" -*-
    
-   Copyright (C) 1996-2000 by Andrew Tridgell 
+   Copyright (C) 1996-2001 by Andrew Tridgell 
    Copyright (C) Paul Mackerras 1996
+   Copyright (C) 2001 by Martin Pool <mbp@samba.org>
    
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -28,18 +29,24 @@
 /* if no timeout is specified then use a 60 second select timeout */
 #define SELECT_TIMEOUT 60
 
-extern int bwlimit;
-
 static int io_multiplexing_out;
 static int io_multiplexing_in;
 static int multiplex_in_fd;
 static int multiplex_out_fd;
 static time_t last_io;
-static int eof_error=1;
+static int no_flush;
+
+extern int bwlimit;
 extern int verbose;
 extern int io_timeout;
 extern struct stats stats;
 
+
+/** Ignore EOF errors while reading a module listing if the remote
+    version is 24 or less. */
+int kludge_around_eof = False;
+
+
 static int io_error_fd = -1;
 
 static void read_loop(int fd, char *buf, int len);
@@ -48,6 +55,8 @@ static void check_timeout(void)
 {
 	extern int am_server, am_daemon;
 	time_t t;
+
+	err_list_push();
 	
 	if (!io_timeout) return;
 
@@ -60,7 +69,7 @@ static void check_timeout(void)
 
 	if (last_io && io_timeout && (t-last_io) >= io_timeout) {
 		if (!am_server && !am_daemon) {
-			rprintf(FERROR,"io timeout after %d second - exiting\n", 
+			rprintf(FERROR,"io timeout after %d seconds - exiting\n", 
 				(int)(t-last_io));
 		}
 		exit_cleanup(RERR_TIMEOUT);
@@ -81,6 +90,8 @@ static void read_error_fd(void)
 	int fd = io_error_fd;
 	int tag, len;
 
+        /* io_error_fd is temporarily disabled -- is this meant to
+         * prevent indefinite recursion? */
 	io_error_fd = -1;
 
 	read_loop(fd, buf, 4);
@@ -102,18 +113,64 @@ static void read_error_fd(void)
 }
 
 
-static int no_flush;
+static void whine_about_eof (void)
+{
+	/**
+	   It's almost always an error to get an EOF when we're trying
+	   to read from the network, because the protocol is
+	   self-terminating.
+	   
+	   However, there is one unfortunate cases where it is not,
+	   which is rsync <2.4.6 sending a list of modules on a
+	   server, since the list is terminated by closing the socket.
+	   So, for the section of the program where that is a problem
+	   (start_socket_client), kludge_around_eof is True and we
+	   just exit.
+	*/
+
+	if (kludge_around_eof)
+		exit_cleanup (0);
+	else {
+		rprintf (FERROR,
+			 "%s: connection unexpectedly closed "
+			 "(%.0f bytes read so far)\n",
+			 RSYNC_NAME, (double)stats.total_read);
+	
+		exit_cleanup (RERR_STREAMIO);
+	}
+}
 
-/* read from a socket with IO timeout. return the number of
-   bytes read. If no bytes can be read then exit, never return
-   a number <= 0 */
-static int read_timeout(int fd, char *buf, int len)
+
+static void die_from_readerr (int err)
+{
+	/* this prevents us trying to write errors on a dead socket */
+	io_multiplexing_close();
+				
+	rprintf(FERROR, "%s: read error: %s\n",
+		RSYNC_NAME, strerror (err));
+	exit_cleanup(RERR_STREAMIO);
+}
+
+
+/*!
+ * Read from a socket with IO timeout. return the number of bytes
+ * read. If no bytes can be read then exit, never return a number <= 0.
+ *
+ * TODO: If the remote shell connection fails, then current versions
+ * actually report an "unexpected EOF" error here.  Since it's a
+ * fairly common mistake to try to use rsh when ssh is required, we
+ * should trap that: if we fail to read any data at all, we should
+ * give a better explanation.  We can tell whether the connection has
+ * started by looking e.g. at whether the remote version is known yet.
+ */
+static int read_timeout (int fd, char *buf, int len)
 {
 	int n, ret=0;
 
 	io_flush();
 
 	while (ret == 0) {
+		/* until we manage to read *something* */
 		fd_set fds;
 		struct timeval tv;
 		int fd_count = fd+1;
@@ -153,38 +210,27 @@ static int read_timeout(int fd, char *buf, int len)
 			if (io_timeout)
 				last_io = time(NULL);
 			continue;
+		} else if (n == 0) {
+			whine_about_eof ();
+			return -1; /* doesn't return */
+		} else if (n == -1) {
+			if (errno == EINTR || errno == EWOULDBLOCK ||
+			    errno == EAGAIN) 
+				continue;
+			else
+				die_from_readerr (errno);
 		}
-
-		if (n == -1 && errno == EINTR) {
-			continue;
-		}
-
-		if (n == -1 && 
-		    (errno == EWOULDBLOCK || errno == EAGAIN)) {
-			continue;
-		}
-
-
-		if (n == 0) {
-			if (eof_error) {
-				rprintf(FERROR,"unexpected EOF in read_timeout\n");
-			}
-			exit_cleanup(RERR_STREAMIO);
-		}
-
-		/* this prevents us trying to write errors on a dead socket */
-		io_multiplexing_close();
-
-		rprintf(FERROR,"read error: %s\n", strerror(errno));
-		exit_cleanup(RERR_STREAMIO);
 	}
 
 	return ret;
 }
 
-/* continue trying to read len bytes - don't return until len
-   has been read */
-static void read_loop(int fd, char *buf, int len)
+
+
+
+/*! Continue trying to read len bytes - don't return until len has
+  been read.   */
+static void read_loop (int fd, char *buf, int len)
 {
 	while (len) {
 		int n = read_timeout(fd, buf, len);
@@ -194,16 +240,20 @@ static void read_loop(int fd, char *buf, int len)
 	}
 }
 
-/* read from the file descriptor handling multiplexing - 
-   return number of bytes read
-   never return <= 0 */
+
+/**
+ * Read from the file descriptor handling multiplexing - return number
+ * of bytes read.
+ * 
+ * Never returns <= 0. 
+ */
 static int read_unbuffered(int fd, char *buf, int len)
 {
 	static int remaining;
 	int tag, ret=0;
 	char line[1024];
 
-	if (!io_multiplexing_in || fd != multiplex_in_fd) 
+	if (!io_multiplexing_in || fd != multiplex_in_fd)
 		return read_timeout(fd, buf, len);
 
 	while (ret == 0) {
@@ -215,7 +265,7 @@ static int read_unbuffered(int fd, char *buf, int len)
 			continue;
 		}
 
-		read_loop(fd, line, 4);
+		read_loop (fd, line, 4);
 		tag = IVAL(line, 0);
 
 		remaining = tag & 0xFFFFFF;
@@ -249,7 +299,7 @@ static int read_unbuffered(int fd, char *buf, int len)
 
 /* do a buffered read from fd. don't return until all N bytes
    have been read. If all N can't be read then exit with an error */
-static void readfd(int fd,char *buffer,int N)
+static void readfd (int fd, char *buffer, int N)
 {
 	int  ret;
 	int total=0;  
@@ -257,7 +307,7 @@ static void readfd(int fd,char *buffer,int N)
 	while (total < N) {
 		io_flush();
 
-		ret = read_unbuffered(fd,buffer + total,N-total);
+		ret = read_unbuffered (fd, buffer + total, N-total);
 		total += ret;
 	}
 
@@ -307,14 +357,14 @@ void read_buf(int f,char *buf,int len)
 
 void read_sbuf(int f,char *buf,int len)
 {
-	read_buf(f,buf,len);
+	read_buf (f,buf,len);
 	buf[len] = 0;
 }
 
 unsigned char read_byte(int f)
 {
 	unsigned char c;
-	read_buf(f,(char *)&c,1);
+	read_buf (f, (char *)&c, 1);
 	return c;
 }
 
@@ -326,6 +376,8 @@ static void writefd_unbuffered(int fd,char *buf,int len)
 	int fd_count, count;
 	struct timeval tv;
 
+	err_list_push();
+
 	no_flush++;
 
 	while (total < len) {
@@ -364,7 +416,6 @@ static void writefd_unbuffered(int fd,char *buf,int len)
 
 		if (FD_ISSET(fd, &w_fds)) {
 			int ret, n = len-total;
-			
 			ret = write(fd,buf+total,n);
 
 			if (ret == -1 && errno == EINTR) {
@@ -378,7 +429,10 @@ static void writefd_unbuffered(int fd,char *buf,int len)
 			}
 
 			if (ret <= 0) {
-				rprintf(FERROR,"erroring writing %d bytes - exiting\n", len);
+				rprintf(FERROR,
+					"error writing %d unbuffered bytes"
+					" - exiting: %s\n", len,
+					strerror(errno));
 				exit_cleanup(RERR_STREAMIO);
 			}
 
@@ -446,6 +500,9 @@ static void mplex_write(int fd, enum logcode code, char *buf, int len)
 void io_flush(void)
 {
 	int fd = multiplex_out_fd;
+
+	err_list_push();
+
 	if (!io_buffer_count || no_flush) return;
 
 	if (io_multiplexing_out) {
@@ -467,21 +524,12 @@ void io_end_buffering(int fd)
 	}
 }
 
-/* some OSes have a bug where an exit causes the pending writes on
-   a socket to be flushed. Do an explicit shutdown to try to prevent this */
-void io_shutdown(void)
-{
-	if (multiplex_out_fd != -1) close(multiplex_out_fd);
-	if (io_error_fd != -1) close(io_error_fd);
-	multiplex_out_fd = -1;
-	io_error_fd = -1;
-}
-
-
 static void writefd(int fd,char *buf,int len)
 {
 	stats.total_written += len;
 
+	err_list_push();
+
 	if (!io_buffer || fd != multiplex_out_fd) {
 		writefd_unbuffered(fd, buf, len);
 		return;
@@ -547,10 +595,10 @@ void write_byte(int f,unsigned char c)
 	write_buf(f,(char *)&c,1);
 }
 
+
+
 int read_line(int f, char *buf, int maxlen)
 {
-	eof_error = 0;
-
 	while (maxlen) {
 		buf[0] = 0;
 		read_buf(f, buf, 1);
@@ -569,8 +617,6 @@ int read_line(int f, char *buf, int maxlen)
 		return 0;
 	}
 
-	eof_error = 1;
-
 	return 1;
 }
 
@@ -582,7 +628,7 @@ void io_printf(int fd, const char *format, ...)
 	int len;
 	
 	va_start(ap, format);
-	len = vslprintf(buf, sizeof(buf), format, ap);
+	len = vsnprintf(buf, sizeof(buf), format, ap);
 	va_end(ap);
 
 	if (len < 0) exit_cleanup(RERR_STREAMIO);
@@ -619,14 +665,6 @@ int io_multiplex_write(enum logcode code, char *buf, int len)
 	return 1;
 }
 
-/* write a message to the special error fd */
-int io_error_write(int f, enum logcode code, char *buf, int len)
-{
-	if (f == -1) return 0;
-	mplex_write(f, code, buf, len);
-	return 1;
-}
-
 /* stop output multiplexing */
 void io_multiplexing_close(void)
 {