X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/fe8c0a9824bf990ae3ff692d25105dd2c9f0ebf4..c3563c46ed40c3021b61f5ed228c9eca2d64e1f3:/io.c

diff --git a/io.c b/io.c
index 8eb62c38..39996885 100644
--- a/io.c
+++ b/io.c
@@ -1,5 +1,6 @@
-/* 
-   Copyright (C) Andrew Tridgell 1996
+/* -*- c-file-style: "linux" -*-
+   
+   Copyright (C) 1996-2000 by Andrew Tridgell 
    Copyright (C) Paul Mackerras 1996
    
    This program is free software; you can redistribute it and/or modify
@@ -18,14 +19,16 @@
 */
 
 /*
-  Utilities used in rsync 
+  socket and pipe IO utilities used in rsync 
 
   tridge, June 1996
   */
 #include "rsync.h"
 
-static int64 total_written;
-static int64 total_read;
+/* 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;
@@ -35,27 +38,15 @@ static time_t last_io;
 static int eof_error=1;
 extern int verbose;
 extern int io_timeout;
+extern struct stats stats;
 
+static int io_error_fd = -1;
 
-int64 write_total(void)
-{
-	return total_written;
-}
-
-int64 read_total(void)
-{
-	return total_read;
-}
-
-static int buffer_f_in = -1;
-
-void setup_readbuffer(int f_in)
-{
-	buffer_f_in = f_in;
-}
+static void read_loop(int fd, char *buf, int len);
 
 static void check_timeout(void)
 {
+	extern int am_server, am_daemon;
 	time_t t;
 	
 	if (!io_timeout) return;
@@ -67,22 +58,61 @@ static void check_timeout(void)
 
 	t = time(NULL);
 
-	if (last_io && io_timeout && (t-last_io)>io_timeout) {
-		rprintf(FERROR,"read timeout after %d second - exiting\n", 
-			(int)(t-last_io));
-		exit_cleanup(1);
+	if (last_io && io_timeout && (t-last_io) >= io_timeout) {
+		if (!am_server && !am_daemon) {
+			rprintf(FERROR,"io timeout after %d second - exiting\n", 
+				(int)(t-last_io));
+		}
+		exit_cleanup(RERR_TIMEOUT);
+	}
+}
+
+/* setup the fd used to propogate errors */
+void io_set_error_fd(int fd)
+{
+	io_error_fd = fd;
+}
+
+/* read some data from the error fd and write it to the write log code */
+static void read_error_fd(void)
+{
+	char buf[200];
+	int n;
+	int fd = io_error_fd;
+	int tag, len;
+
+	io_error_fd = -1;
+
+	read_loop(fd, buf, 4);
+	tag = IVAL(buf, 0);
+
+	len = tag & 0xFFFFFF;
+	tag = tag >> 24;
+	tag -= MPLEX_BASE;
+
+	while (len) {
+		n = len;
+		if (n > (sizeof(buf)-1)) n = sizeof(buf)-1;
+		read_loop(fd, buf, n);
+		rwrite((enum logcode)tag, buf, n);
+		len -= n;
 	}
+
+	io_error_fd = fd;
 }
 
 
-static char *read_buffer;
-static char *read_buffer_p;
-static int read_buffer_len;
-static int read_buffer_size;
+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.
+ */
 static int read_timeout(int fd, char *buf, int len)
 {
 	int n, ret=0;
@@ -92,18 +122,34 @@ static int read_timeout(int fd, char *buf, int len)
 	while (ret == 0) {
 		fd_set fds;
 		struct timeval tv;
+		int fd_count = fd+1;
 
 		FD_ZERO(&fds);
 		FD_SET(fd, &fds);
-		tv.tv_sec = io_timeout;
+		if (io_error_fd != -1) {
+			FD_SET(io_error_fd, &fds);
+			if (io_error_fd > fd) fd_count = io_error_fd+1;
+		}
+
+		tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT;
 		tv.tv_usec = 0;
 
-		if (select(fd+1, &fds, NULL, NULL, 
-			   io_timeout?&tv:NULL) != 1) {
+		errno = 0;
+
+		if (select(fd_count, &fds, NULL, NULL, &tv) < 1) {
+			if (errno == EBADF) {
+				exit_cleanup(RERR_SOCKETIO);
+			}
 			check_timeout();
 			continue;
 		}
 
+		if (io_error_fd != -1 && FD_ISSET(io_error_fd, &fds)) {
+			read_error_fd();
+		}
+
+		if (!FD_ISSET(fd, &fds)) continue;
+
 		n = read(fd, buf, len);
 
 		if (n > 0) {
@@ -119,15 +165,24 @@ static int read_timeout(int fd, char *buf, int len)
 			continue;
 		}
 
+		if (n == -1 && 
+		    (errno == EWOULDBLOCK || errno == EAGAIN)) {
+			continue;
+		}
+
+
 		if (n == 0) {
 			if (eof_error) {
-				rprintf(FERROR,"EOF in read_timeout\n");
+				rprintf(FERROR,"unexpected EOF in read_timeout\n");
 			}
-			exit_cleanup(1);
+			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(1);
+		exit_cleanup(RERR_STREAMIO);
 	}
 
 	return ret;
@@ -145,13 +200,12 @@ static void read_loop(int fd, char *buf, int len)
 	}
 }
 
-/* read from the file descriptor handing multiplexing - 
+/* read from the file descriptor handling multiplexing - 
    return number of bytes read
    never return <= 0 */
 static int read_unbuffered(int fd, char *buf, int len)
 {
 	static int remaining;
-	char ibuf[4];
 	int tag, ret=0;
 	char line[1024];
 
@@ -167,8 +221,8 @@ static int read_unbuffered(int fd, char *buf, int len)
 			continue;
 		}
 
-		read_loop(fd, ibuf, 4);
-		tag = IVAL(ibuf, 0);
+		read_loop(fd, line, 4);
+		tag = IVAL(line, 0);
 
 		remaining = tag & 0xFFFFFF;
 		tag = tag >> 24;
@@ -179,19 +233,19 @@ static int read_unbuffered(int fd, char *buf, int len)
 
 		if (tag != FERROR && tag != FINFO) {
 			rprintf(FERROR,"unexpected tag %d\n", tag);
-			exit_cleanup(1);
+			exit_cleanup(RERR_STREAMIO);
 		}
 
 		if (remaining > sizeof(line)-1) {
 			rprintf(FERROR,"multiplexing overflow %d\n\n", 
 				remaining);
-			exit_cleanup(1);
+			exit_cleanup(RERR_STREAMIO);
 		}
 
 		read_loop(fd, line, remaining);
 		line[remaining] = 0;
 
-		rprintf(tag,"%s", line);
+		rprintf((enum logcode)tag,"%s", line);
 		remaining = 0;
 	}
 
@@ -199,40 +253,6 @@ static int read_unbuffered(int fd, char *buf, int len)
 }
 
 
-
-/* This function was added to overcome a deadlock problem when using
- * ssh.  It looks like we can't allow our receive queue to get full or
- * ssh will clag up. Uggh.  */
-static void read_check(int f)
-{
-	int n = 8192;
-
-	if (f == -1) return;
-
-	if (read_buffer_len == 0) {
-		read_buffer_p = read_buffer;
-	}
-
-	if (n > MAX_READ_BUFFER/4)
-		n = MAX_READ_BUFFER/4;
-
-	if (read_buffer_p != read_buffer) {
-		memmove(read_buffer,read_buffer_p,read_buffer_len);
-		read_buffer_p = read_buffer;
-	}
-
-	if (n > (read_buffer_size - read_buffer_len)) {
-		read_buffer_size += n;
-		read_buffer = (char *)Realloc(read_buffer,read_buffer_size);
-		if (!read_buffer) out_of_memory("read check");      
-		read_buffer_p = read_buffer;      
-	}
-
-	n = read_unbuffered(f,read_buffer+read_buffer_len,n);
-	read_buffer_len += n;
-}
-
-
 /* 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)
@@ -240,34 +260,26 @@ static void readfd(int fd,char *buffer,int N)
 	int  ret;
 	int total=0;  
 	
-	if (read_buffer_len < N && N < 1024) {
-		read_check(buffer_f_in);
-	}
-	
 	while (total < N) {
-		if (read_buffer_len > 0 && buffer_f_in == fd) {
-			ret = MIN(read_buffer_len,N-total);
-			memcpy(buffer+total,read_buffer_p,ret);
-			read_buffer_p += ret;
-			read_buffer_len -= ret;
-			total += ret;
-			continue;
-		} 
-
 		io_flush();
 
 		ret = read_unbuffered(fd,buffer + total,N-total);
 		total += ret;
 	}
+
+	stats.total_read += total;
 }
 
 
 int32 read_int(int f)
 {
 	char b[4];
+	int32 ret;
+
 	readfd(f,b,4);
-	total_read += 4;
-	return IVAL(b,0);
+	ret = IVAL(b,0);
+	if (ret == (int32)0xffffffff) return -1;
+	return ret;
 }
 
 int64 read_longint(int f)
@@ -277,15 +289,16 @@ int64 read_longint(int f)
 	char b[8];
 	ret = read_int(f);
 
-	if ((int32)ret != (int32)0xffffffff) return ret;
+	if ((int32)ret != (int32)0xffffffff) {
+		return ret;
+	}
 
 #ifdef NO_INT64
 	rprintf(FERROR,"Integer overflow - attempted 64 bit offset\n");
-	exit_cleanup(1);
+	exit_cleanup(RERR_UNSUPPORTED);
 #else
 	if (remote_version >= 16) {
 		readfd(f,b,8);
-		total_read += 8;
 		ret = IVAL(b,0) | (((int64)IVAL(b,4))<<32);
 	}
 #endif
@@ -296,7 +309,6 @@ int64 read_longint(int f)
 void read_buf(int f,char *buf,int len)
 {
 	readfd(f,buf,len);
-	total_read += len;
 }
 
 void read_sbuf(int f,char *buf,int len)
@@ -312,68 +324,91 @@ unsigned char read_byte(int f)
 	return c;
 }
 
-
-
-/* write len bytes to fd, possibly reading from buffer_f_in if set
-   in order to unclog the pipe. don't return until all len
-   bytes have been written */
+/* write len bytes to fd */
 static void writefd_unbuffered(int fd,char *buf,int len)
 {
 	int total = 0;
 	fd_set w_fds, r_fds;
 	int fd_count, count;
 	struct timeval tv;
-	int reading;
 
-	reading = (buffer_f_in != -1 && read_buffer_len < MAX_READ_BUFFER);
+	no_flush++;
 
 	while (total < len) {
 		FD_ZERO(&w_fds);
 		FD_ZERO(&r_fds);
 		FD_SET(fd,&w_fds);
-		fd_count = fd+1;
+		fd_count = fd;
 
-		if (reading) {
-			FD_SET(buffer_f_in,&r_fds);
-			if (buffer_f_in > fd) 
-				fd_count = buffer_f_in+1;
+		if (io_error_fd != -1) {
+			FD_SET(io_error_fd,&r_fds);
+			if (io_error_fd > fd_count) 
+				fd_count = io_error_fd;
 		}
 
-		tv.tv_sec = io_timeout;
+		tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT;
 		tv.tv_usec = 0;
 
-		count = select(fd_count,
-			       reading?&r_fds:NULL,
+		errno = 0;
+
+		count = select(fd_count+1,
+			       io_error_fd != -1?&r_fds:NULL,
 			       &w_fds,NULL,
-			       io_timeout?&tv:NULL);
+			       &tv);
 
 		if (count <= 0) {
+			if (errno == EBADF) {
+				exit_cleanup(RERR_SOCKETIO);
+			}
 			check_timeout();
 			continue;
 		}
 
+		if (io_error_fd != -1 && FD_ISSET(io_error_fd, &r_fds)) {
+			read_error_fd();
+		}
+
 		if (FD_ISSET(fd, &w_fds)) {
-			int ret = write(fd,buf+total,len-total);
+			int ret, n = len-total;
+			
+			ret = write(fd,buf+total,n);
 
 			if (ret == -1 && errno == EINTR) {
 				continue;
 			}
 
+			if (ret == -1 && 
+			    (errno == EWOULDBLOCK || errno == EAGAIN)) {
+				msleep(1);
+				continue;
+			}
+
 			if (ret <= 0) {
 				rprintf(FERROR,"erroring writing %d bytes - exiting\n", len);
-				exit_cleanup(1);
+				exit_cleanup(RERR_STREAMIO);
 			}
 
+			/* Sleep after writing to limit I/O bandwidth */
+			if (bwlimit)
+			{
+			    tv.tv_sec = 0;
+			    tv.tv_usec = ret * 1000 / bwlimit;
+			    while (tv.tv_usec > 1000000)
+			    {
+				tv.tv_sec++;
+				tv.tv_usec -= 1000000;
+			    }
+			    select(0, NULL, NULL, NULL, &tv);
+ 			}
+ 
 			total += ret;
+
 			if (io_timeout)
 				last_io = time(NULL);
-			continue;
-		}
-
-		if (reading && FD_ISSET(buffer_f_in, &r_fds)) {
-			read_check(buffer_f_in);
 		}
 	}
+
+	no_flush--;
 }
 
 
@@ -384,40 +419,76 @@ void io_start_buffering(int fd)
 {
 	if (io_buffer) return;
 	multiplex_out_fd = fd;
-	io_buffer = (char *)malloc(IO_BUFFER_SIZE+4);
+	io_buffer = (char *)malloc(IO_BUFFER_SIZE);
 	if (!io_buffer) out_of_memory("writefd");
 	io_buffer_count = 0;
+}
 
-	/* leave room for the multiplex header in case it's needed */
-	io_buffer += 4;
+/* write an message to a multiplexed stream. If this fails then rsync
+   exits */
+static void mplex_write(int fd, enum logcode code, char *buf, int len)
+{
+	char buffer[4096];
+	int n = len;
+
+	SIVAL(buffer, 0, ((MPLEX_BASE + (int)code)<<24) + len);
+
+	if (n > (sizeof(buffer)-4)) {
+		n = sizeof(buffer)-4;
+	}
+
+	memcpy(&buffer[4], buf, n);
+	writefd_unbuffered(fd, buffer, n+4);
+
+	len -= n;
+	buf += n;
+
+	if (len) {
+		writefd_unbuffered(fd, buf, len);
+	}
 }
 
+
 void io_flush(void)
 {
 	int fd = multiplex_out_fd;
-	if (!io_buffer_count) return;
+	if (!io_buffer_count || no_flush) return;
 
 	if (io_multiplexing_out) {
-		SIVAL(io_buffer-4, 0, (MPLEX_BASE<<24) + io_buffer_count);
-		writefd_unbuffered(fd, io_buffer-4, io_buffer_count+4);
+		mplex_write(fd, FNONE, io_buffer, io_buffer_count);
 	} else {
 		writefd_unbuffered(fd, io_buffer, io_buffer_count);
 	}
 	io_buffer_count = 0;
 }
 
+
+/* XXX: fd is ignored, which seems a little strange. */
 void io_end_buffering(int fd)
 {
 	io_flush();
 	if (!io_multiplexing_out) {
-		free(io_buffer-4);
+		free(io_buffer);
 		io_buffer = NULL;
 	}
 }
 
+/* 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)
 {
-	if (!io_buffer) {
+	stats.total_written += len;
+
+	if (!io_buffer || fd != multiplex_out_fd) {
 		writefd_unbuffered(fd, buf, len);
 		return;
 	}
@@ -441,9 +512,13 @@ void write_int(int f,int32 x)
 	char b[4];
 	SIVAL(b,0,x);
 	writefd(f,b,4);
-	total_written += 4;
 }
 
+
+/*
+ * Note: int64 may actually be a 32-bit type if ./configure couldn't find any
+ * 64-bit types on this platform.
+ */
 void write_longint(int f, int64 x)
 {
 	extern int remote_version;
@@ -454,22 +529,20 @@ void write_longint(int f, int64 x)
 		return;
 	}
 
-	write_int(f, -1);
+	write_int(f, (int32)0xFFFFFFFF);
 	SIVAL(b,0,(x&0xFFFFFFFF));
 	SIVAL(b,4,((x>>32)&0xFFFFFFFF));
 
 	writefd(f,b,8);
-	total_written += 8;
 }
 
 void write_buf(int f,char *buf,int len)
 {
 	writefd(f,buf,len);
-	total_written += len;
 }
 
 /* write a string to the connection */
-void write_sbuf(int f,char *buf)
+static void write_sbuf(int f,char *buf)
 {
 	write_buf(f, buf, strlen(buf));
 }
@@ -515,10 +588,10 @@ void io_printf(int fd, const char *format, ...)
 	int len;
 	
 	va_start(ap, format);
-	len = vslprintf(buf, sizeof(buf)-1, format, ap);
+	len = vslprintf(buf, sizeof(buf), format, ap);
 	va_end(ap);
 
-	if (len < 0) exit_cleanup(1);
+	if (len < 0) exit_cleanup(RERR_STREAMIO);
 
 	write_sbuf(fd, buf);
 }
@@ -538,29 +611,31 @@ void io_start_multiplex_in(int fd)
 {
 	multiplex_in_fd = fd;
 	io_flush();
-	if (read_buffer_len) {
-		fprintf(stderr,"ERROR: data in read buffer at mplx start\n");
-		exit_cleanup(1);
-	}
-
 	io_multiplexing_in = 1;
 }
 
-/* write an message to the error stream */
-int io_multiplex_write(int f, char *buf, int len)
+/* write an message to the multiplexed error stream */
+int io_multiplex_write(enum logcode code, char *buf, int len)
 {
 	if (!io_multiplexing_out) return 0;
 
 	io_flush();
+	stats.total_written += (len+4);
+	mplex_write(multiplex_out_fd, code, buf, len);
+	return 1;
+}
 
-	SIVAL(io_buffer-4, 0, ((MPLEX_BASE + f)<<24) + len);
-	memcpy(io_buffer, buf, len);
-
-	writefd_unbuffered(multiplex_out_fd, io_buffer-4, len+4);
+/* 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;
 }
 
-void io_close_input(int fd)
+/* stop output multiplexing */
+void io_multiplexing_close(void)
 {
-	buffer_f_in = -1;
+	io_multiplexing_out = 0;
 }
+