Add a little more protocol documentation.

[rsync/rsync.git] / io.c

diff --git a/io.c b/io.c
index 253344b..dac0744 100644 (file)
--- a/io.c
+++ b/io.c
@@ -1,6 +1,6 @@
 /* -*- c-file-style: "linux" -*-
    
-   Copyright (C) 1996-2000 by Andrew Tridgell 
+   Copyright (C) 1996-2001 by Andrew Tridgell 
    Copyright (C) Paul Mackerras 1996
    
    This program is free software; you can redistribute it and/or modify
@@ -48,6 +48,8 @@ static void check_timeout(void)
 {
        extern int am_server, am_daemon;
        time_t t;
+
+       err_list_push();
        
        if (!io_timeout) return;
 
@@ -60,7 +62,7 @@ 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 +83,8 @@ 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);
@@ -104,9 +108,17 @@ static void read_error_fd(void)
 
 static int no_flush;
 
-/* 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 */
+/*
+ * 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;
@@ -167,7 +179,10 @@ static int read_timeout(int fd, char *buf, int len)
 
                if (n == 0) {
                        if (eof_error) {
-                               rprintf(FERROR,"unexpected EOF in read_timeout\n");
+                               rprintf(FERROR,
+                                        "%s: connection to server unexpectedly closed"
+                                        " (%.0f bytes read so far)\n",
+                                        RSYNC_NAME, (double)stats.total_read);
                        }
                        exit_cleanup(RERR_STREAMIO);
                }
@@ -326,6 +341,8 @@ 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 +381,6 @@ 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 +394,10 @@ 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 +465,9 @@ 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 +489,12 @@ 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;
@@ -582,7 +595,7 @@ 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 +632,6 @@ 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)
 {