X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/07b7c86c0672c38648fb715efbc0bfffd81ed182..8b35435f7cc4708400c652434615ce48dc493de4:/io.c

diff --git a/io.c b/io.c
index 9e2a4757..6cdbe6bf 100644
--- a/io.c
+++ b/io.c
@@ -18,7 +18,7 @@
 */
 
 /*
-  Utilities used in rsync 
+  socket and pipe IO utilities used in rsync 
 
   tridge, June 1996
   */
@@ -38,6 +38,9 @@ extern int io_timeout;
 extern struct stats stats;
 
 static int buffer_f_in = -1;
+static int io_error_fd = -1;
+
+static void read_loop(int fd, char *buf, int len);
 
 void setup_readbuffer(int f_in)
 {
@@ -64,13 +67,42 @@ static void check_timeout(void)
 	}
 }
 
+/* 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;
-static int no_flush_read;
 
 /* read from a socket with IO timeout. return the number of
    bytes read. If no bytes can be read then exit, never return
@@ -79,24 +111,39 @@ static int read_timeout(int fd, char *buf, int len)
 {
 	int n, ret=0;
 
-	no_flush_read++;
 	io_flush();
-	no_flush_read--;
 
 	while (ret == 0) {
 		fd_set fds;
 		struct timeval tv;
+		int fd_count = fd+1;
 
 		FD_ZERO(&fds);
 		FD_SET(fd, &fds);
+		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, &tv) != 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) {
@@ -112,6 +159,7 @@ static int read_timeout(int fd, char *buf, int len)
 			continue;
 		}
 
+
 		if (n == 0) {
 			if (eof_error) {
 				rprintf(FERROR,"unexpected EOF in read_timeout\n");
@@ -119,6 +167,9 @@ static int read_timeout(int fd, char *buf, int len)
 			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);
 	}
@@ -144,7 +195,6 @@ static void read_loop(int fd, char *buf, int len)
 static int read_unbuffered(int fd, char *buf, int len)
 {
 	static int remaining;
-	char ibuf[4];
 	int tag, ret=0;
 	char line[1024];
 
@@ -160,8 +210,8 @@ 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;
@@ -184,7 +234,7 @@ static int read_unbuffered(int fd, char *buf, int len)
 		read_loop(fd, line, remaining);
 		line[remaining] = 0;
 
-		rprintf(tag,"%s", line);
+		rprintf((enum logcode)tag,"%s", line);
 		remaining = 0;
 	}
 
@@ -192,40 +242,6 @@ 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)
@@ -233,23 +249,8 @@ 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;
-		} 
-
-		no_flush_read++;
 		io_flush();
-		no_flush_read--;
 
 		ret = read_unbuffered(fd,buffer + total,N-total);
 		total += ret;
@@ -323,7 +324,6 @@ static void writefd_unbuffered(int fd,char *buf,int len)
 	fd_set w_fds, r_fds;
 	int fd_count, count;
 	struct timeval tv;
-	int reading=0;
 
 	no_flush++;
 
@@ -331,40 +331,39 @@ static void writefd_unbuffered(int fd,char *buf,int len)
 		FD_ZERO(&w_fds);
 		FD_ZERO(&r_fds);
 		FD_SET(fd,&w_fds);
-		fd_count = fd+1;
-
-		if (!no_flush_read) {
-			reading = (buffer_f_in != -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?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,
 			       &tv);
 
 		if (count <= 0) {
+			if (errno == EBADF) {
+				exit_cleanup(RERR_SOCKETIO);
+			}
 			check_timeout();
 			continue;
 		}
 
-		if (reading && FD_ISSET(buffer_f_in, &r_fds)) {
-			read_check(buffer_f_in);
+		if (io_error_fd != -1 && FD_ISSET(io_error_fd, &r_fds)) {
+			read_error_fd();
 		}
 
 		if (FD_ISSET(fd, &w_fds)) {
 			int ret, n = len-total;
 			
-			if (n > PIPE_BUF) n = PIPE_BUF;
-
 			ret = write(fd,buf+total,n?n:1);
 
 			if (ret == -1 && errno == EINTR) {
@@ -394,22 +393,43 @@ 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;
+}
+
+/* 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;
+	}
 
-	/* leave room for the multiplex header in case it's needed */
-	io_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 || 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);
 	}
@@ -420,7 +440,7 @@ void io_end_buffering(int fd)
 {
 	io_flush();
 	if (!io_multiplexing_out) {
-		free(io_buffer-4);
+		free(io_buffer);
 		io_buffer = NULL;
 	}
 }
@@ -429,7 +449,7 @@ static void writefd(int fd,char *buf,int len)
 {
 	stats.total_written += len;
 
-	if (!io_buffer) {
+	if (!io_buffer || fd != multiplex_out_fd) {
 		writefd_unbuffered(fd, buf, len);
 		return;
 	}
@@ -547,31 +567,36 @@ 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(RERR_STREAMIO);
-	}
-
 	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();
-
-	SIVAL(io_buffer-4, 0, ((MPLEX_BASE + f)<<24) + len);
-	memcpy(io_buffer, buf, len);
-
 	stats.total_written += (len+4);
+	mplex_write(multiplex_out_fd, code, buf, len);
+	return 1;
+}
 
-	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;
 }
 
+/* stop output multiplexing */
+void io_multiplexing_close(void)
+{
+	io_multiplexing_out = 0;
+}
+
 void io_close_input(int fd)
 {
 	buffer_f_in = -1;
 }
+