X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/22d6234e04e087b9111243d1f940db7c6d59fd76..08f15335b5b469b29cbdacd0fc5ba48d76acf280:/io.c

diff --git a/io.c b/io.c
index b48ae0f9..6f3854e3 100644
--- a/io.c
+++ b/io.c
@@ -18,168 +18,244 @@
 */
 
 /*
-  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
 
+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;
 extern int verbose;
-extern int sparse_files;
 extern int io_timeout;
+extern struct stats stats;
+
+static int buffer_f_in = -1;
+static int io_error_fd = -1;
 
-int64 write_total(void)
+void setup_readbuffer(int f_in)
 {
-  return total_written;
+	buffer_f_in = f_in;
 }
 
-int64 read_total(void)
+static void check_timeout(void)
 {
-  return total_read;
-}
+	time_t t;
+	
+	if (!io_timeout) return;
 
-static int buffer_f_in = -1;
+	if (!last_io) {
+		last_io = time(NULL);
+		return;
+	}
+
+	t = time(NULL);
 
-void setup_nonblocking(int f_in,int f_out)
+	if (last_io && io_timeout && (t-last_io) >= io_timeout) {
+		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)
 {
-	set_blocking(f_out,0);
-	buffer_f_in = f_in;
+	io_error_fd = fd;
 }
 
+/* read some data from the error fd and write it to FERROR */
+static void read_error_fd(void)
+{
+	char buf[200];
+	int n;
+	int fd = io_error_fd;
+	io_error_fd = -1;
+
+	n = read(fd, buf, sizeof(buf)-1);
+	if (n > 0) {
+		rwrite(FERROR, buf, n);
+	}
 
-static char *read_buffer;
-static char *read_buffer_p;
-static int read_buffer_len;
-static int read_buffer_size;
+	io_error_fd = fd;
+}
 
 
-/* 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)
+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 */
+static int read_timeout(int fd, char *buf, int len)
 {
-	int n;
+	int n, ret=0;
 
-	if (f == -1) return;
+	io_flush();
 
-	if (read_buffer_len == 0) {
-		read_buffer_p = read_buffer;
-	}
+	while (ret == 0) {
+		fd_set fds;
+		struct timeval tv;
+		int fd_count = fd+1;
 
-	if ((n=num_waiting(f)) <= 0)
-		return;
+		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;
+		}
 
-	/* things could deteriorate if we read in really small chunks */
-	if (n < 10) n = 1024;
+		tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT;
+		tv.tv_usec = 0;
 
-	if (n > MAX_READ_BUFFER/4)
-		n = MAX_READ_BUFFER/4;
+		errno = 0;
 
-	if (read_buffer_p != read_buffer) {
-		memmove(read_buffer,read_buffer_p,read_buffer_len);
-		read_buffer_p = read_buffer;
-	}
+		if (select(fd_count, &fds, NULL, NULL, &tv) < 1) {
+			if (errno == EBADF) {
+				exit_cleanup(RERR_SOCKETIO);
+			}
+			check_timeout();
+			continue;
+		}
 
-	if (n > (read_buffer_size - read_buffer_len)) {
-		read_buffer_size += n;
-		if (!read_buffer)
-			read_buffer = (char *)malloc(read_buffer_size);
-		else
-			read_buffer = (char *)realloc(read_buffer,read_buffer_size);
-		if (!read_buffer) out_of_memory("read check");      
-		read_buffer_p = read_buffer;      
-	}
+		if (io_error_fd != -1 && FD_ISSET(io_error_fd, &fds)) {
+			read_error_fd();
+		}
 
-	n = read(f,read_buffer+read_buffer_len,n);
-	if (n > 0) {
-		read_buffer_len += n;
+		if (!FD_ISSET(fd, &fds)) continue;
+
+		n = read(fd, buf, len);
+
+		if (n > 0) {
+			buf += n;
+			len -= n;
+			ret += n;
+			if (io_timeout)
+				last_io = time(NULL);
+			continue;
+		}
+
+		if (n == -1 && errno == EINTR) {
+			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;
 }
 
-static time_t last_io;
+/* 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);
 
+		buf += n;
+		len -= n;
+	}
+}
 
-static void check_timeout(void)
+/* 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)
 {
-	time_t t;
-	
-	if (!io_timeout) return;
+	static int remaining;
+	char ibuf[4];
+	int tag, ret=0;
+	char line[1024];
+
+	if (!io_multiplexing_in || fd != multiplex_in_fd) 
+		return read_timeout(fd, buf, len);
+
+	while (ret == 0) {
+		if (remaining) {
+			len = MIN(len, remaining);
+			read_loop(fd, buf, len);
+			remaining -= len;
+			ret = len;
+			continue;
+		}
 
-	if (!last_io) {
-		last_io = time(NULL);
-		return;
-	}
+		read_loop(fd, ibuf, 4);
+		tag = IVAL(ibuf, 0);
 
-	t = time(NULL);
+		remaining = tag & 0xFFFFFF;
+		tag = tag >> 24;
 
-	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 (tag == MPLEX_BASE) continue;
+
+		tag -= MPLEX_BASE;
+
+		if (tag != FERROR && tag != FINFO) {
+			rprintf(FERROR,"unexpected tag %d\n", tag);
+			exit_cleanup(RERR_STREAMIO);
+		}
+
+		if (remaining > sizeof(line)-1) {
+			rprintf(FERROR,"multiplexing overflow %d\n\n", 
+				remaining);
+			exit_cleanup(RERR_STREAMIO);
+		}
+
+		read_loop(fd, line, remaining);
+		line[remaining] = 0;
+
+		rprintf(tag,"%s", line);
+		remaining = 0;
 	}
+
+	return ret;
 }
 
-static int readfd(int fd,char *buffer,int 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)
 {
 	int  ret;
 	int total=0;  
-	struct timeval tv;
-	
-	if (read_buffer_len < N)
-		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;
-		} 
-
-		while ((ret = read(fd,buffer + total,N-total)) == -1) {
-			fd_set fds;
+		io_flush();
 
-			if (errno != EAGAIN && errno != EWOULDBLOCK)
-				return -1;
-			FD_ZERO(&fds);
-			FD_SET(fd, &fds);
-			tv.tv_sec = io_timeout;
-			tv.tv_usec = 0;
-
-			if (select(fd+1, &fds, NULL, NULL, 
-				   io_timeout?&tv:NULL) != 1) {
-				check_timeout();
-			}
-		}
-
-		if (ret <= 0)
-			return total;
+		ret = read_unbuffered(fd,buffer + total,N-total);
 		total += ret;
 	}
 
-	if (io_timeout)
-		last_io = time(NULL);
-	return total;
+	stats.total_read += total;
 }
 
 
 int32 read_int(int f)
 {
-  int ret;
-  char b[4];
-  if ((ret=readfd(f,b,4)) != 4) {
-    if (verbose > 1) 
-      rprintf(FERROR,"(%d) Error reading %d bytes : %s\n",
-	      getpid(),4,ret==-1?strerror(errno):"EOF");
-    exit_cleanup(1);
-  }
-  total_read += 4;
-  return IVAL(b,0);
+	char b[4];
+	int32 ret;
+
+	readfd(f,b,4);
+	ret = IVAL(b,0);
+	if (ret == (int32)0xffffffff) return -1;
+	return ret;
 }
 
 int64 read_longint(int f)
@@ -189,20 +265,16 @@ 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) {
-		if ((ret=readfd(f,b,8)) != 8) {
-			if (verbose > 1) 
-				rprintf(FERROR,"(%d) Error reading %d bytes : %s\n",
-					getpid(),8,ret==-1?strerror(errno):"EOF");
-			exit_cleanup(1);
-		}
-		total_read += 8;
+		readfd(f,b,8);
 		ret = IVAL(b,0) | (((int64)IVAL(b,4))<<32);
 	}
 #endif
@@ -212,14 +284,7 @@ int64 read_longint(int f)
 
 void read_buf(int f,char *buf,int len)
 {
-  int ret;
-  if ((ret=readfd(f,buf,len)) != len) {
-    if (verbose > 1) 
-      rprintf(FERROR,"(%d) Error reading %d bytes : %s\n",
-	      getpid(),len,ret==-1?strerror(errno):"EOF");
-    exit_cleanup(1);
-  }
-  total_read += len;
+	readfd(f,buf,len);
 }
 
 void read_sbuf(int f,char *buf,int len)
@@ -230,186 +295,132 @@ void read_sbuf(int f,char *buf,int len)
 
 unsigned char read_byte(int f)
 {
-  unsigned char c;
-  read_buf(f,(char *)&c,1);
-  return c;
+	unsigned char c;
+	read_buf(f,(char *)&c,1);
+	return c;
 }
 
 
-static char last_byte;
-static int last_sparse;
 
-int sparse_end(int f)
+/* 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 */
+static void writefd_unbuffered(int fd,char *buf,int len)
 {
-	if (last_sparse) {
-		do_lseek(f,-1,SEEK_CUR);
-		return (write(f,&last_byte,1) == 1 ? 0 : -1);
-	}
-	last_sparse = 0;
-	return 0;
-}
+	int total = 0;
+	fd_set w_fds, r_fds;
+	int fd_count, count;
+	struct timeval tv;
 
+	no_flush++;
 
-static int write_sparse(int f,char *buf,int len)
-{
-	int l1=0,l2=0;
-	int ret;
+	while (total < len) {
+		FD_ZERO(&w_fds);
+		FD_ZERO(&r_fds);
+		FD_SET(fd,&w_fds);
+		fd_count = fd;
 
-	for (l1=0;l1<len && buf[l1]==0;l1++) ;
-	for (l2=0;l2<(len-l1) && buf[len-(l2+1)]==0;l2++) ;
+		if (io_error_fd != -1) {
+			FD_SET(io_error_fd,&r_fds);
+			if (io_error_fd > fd_count) 
+				fd_count = io_error_fd;
+		}
 
-	last_byte = buf[len-1];
+		tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT;
+		tv.tv_usec = 0;
 
-	if (l1 == len || l2 > 0)
-		last_sparse=1;
+		errno = 0;
 
-	if (l1 > 0)
-		do_lseek(f,l1,SEEK_CUR);  
+		count = select(fd_count+1,
+			       io_error_fd != -1?&r_fds:NULL,
+			       &w_fds,NULL,
+			       &tv);
 
-	if (l1 == len) 
-		return len;
+		if (count <= 0) {
+			if (errno == EBADF) {
+				exit_cleanup(RERR_SOCKETIO);
+			}
+			check_timeout();
+			continue;
+		}
 
-	if ((ret=write(f,buf+l1,len-(l1+l2))) != len-(l1+l2)) {
-		if (ret == -1 || ret == 0) return ret;
-		return (l1+ret);
-	}
+		if (io_error_fd != -1 && FD_ISSET(io_error_fd, &r_fds)) {
+			read_error_fd();
+		}
 
-	if (l2 > 0)
-		do_lseek(f,l2,SEEK_CUR);
-	
-	return len;
-}
+		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) {
+				continue;
+			}
 
-int write_file(int f,char *buf,int len)
-{
-	int ret = 0;
+			if (ret <= 0) {
+				rprintf(FERROR,"erroring writing %d bytes - exiting\n", len);
+				exit_cleanup(RERR_STREAMIO);
+			}
 
-	if (!sparse_files) 
-		return write(f,buf,len);
+			total += ret;
 
-	while (len>0) {
-		int len1 = MIN(len, SPARSE_WRITE_SIZE);
-		int r1 = write_sparse(f, buf, len1);
-		if (r1 <= 0) {
-			if (ret > 0) return ret;
-			return r1;
+			if (io_timeout)
+				last_io = time(NULL);
 		}
-		len -= r1;
-		buf += r1;
-		ret += r1;
 	}
-	return ret;
-}
-
 
-static int writefd_unbuffered(int fd,char *buf,int len)
-{
-  int total = 0;
-  fd_set w_fds, r_fds;
-  int fd_count, count, got_select=0;
-  struct timeval tv;
-
-  if (buffer_f_in == -1) 
-    return write(fd,buf,len);
-
-  while (total < len) {
-    int ret = write(fd,buf+total,len-total);
-
-    if (ret == 0) return total;
-
-    if (ret == -1 && !(errno == EWOULDBLOCK || errno == EAGAIN)) 
-      return -1;
-
-    if (ret == -1 && got_select) {
-	    /* hmmm, we got a write select on the fd and then failed to write.
-	       Why doesn't that mean that the fd is dead? It doesn't on some
-	       systems it seems (eg. IRIX) */
-	    u_sleep(1000);
-#if 0
-	    rprintf(FERROR,"write exception\n");
-	    exit_cleanup(1);
-#endif
-    }
-
-    got_select = 0;
-
-
-    if (ret == -1) {
-	    if (read_buffer_len < MAX_READ_BUFFER)
-		    read_check(buffer_f_in);
-
-	    fd_count = fd+1;
-	    FD_ZERO(&w_fds);
-	    FD_ZERO(&r_fds);
-	    FD_SET(fd,&w_fds);
-	    if (buffer_f_in != -1) {
-		    FD_SET(buffer_f_in,&r_fds);
-		    if (buffer_f_in > fd) 
-			    fd_count = buffer_f_in+1;
-	    }
-
-	    tv.tv_sec = BLOCKING_TIMEOUT;
-	    tv.tv_usec = 0;
-	    count = select(fd_count,buffer_f_in == -1? NULL: &r_fds,
-			   &w_fds,NULL,&tv);
-
-	    if (count == -1 && errno != EINTR) {
-		    if (verbose > 1) 
-			    rprintf(FERROR,"select error: %s\n", strerror(errno));
-		    exit_cleanup(1);
-	    }
-
-	    if (count == 0) {
-		    check_timeout();
-		    continue;
-	    }
-      
-	    if (FD_ISSET(fd, &w_fds)) {
-		    got_select = 1;
-	    }
-    } else {
-	    total += ret;
-    }
-  }
-
-  if (io_timeout)
-	  last_io = time(NULL);
-
-  return total;
+	no_flush--;
 }
 
+
 static char *io_buffer;
 static int io_buffer_count;
 
 void io_start_buffering(int fd)
 {
-	io_buffer = (char *)malloc(IO_BUFFER_SIZE);
+	if (io_buffer) return;
+	multiplex_out_fd = fd;
+	io_buffer = (char *)malloc(IO_BUFFER_SIZE+4);
 	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;
+}
+
+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);
+	} else {
+		writefd_unbuffered(fd, io_buffer, io_buffer_count);
+	}
+	io_buffer_count = 0;
 }
 
 void io_end_buffering(int fd)
 {
-	if (io_buffer_count) {
-		if (writefd_unbuffered(fd, io_buffer, 
-				       io_buffer_count) != 
-		    io_buffer_count) {
-			rprintf(FERROR,"write failed\n");
-			exit_cleanup(1);
-		}
-		io_buffer_count = 0;
+	io_flush();
+	if (!io_multiplexing_out) {
+		free(io_buffer-4);
+		io_buffer = NULL;
 	}
-	free(io_buffer);
-	io_buffer = NULL;
 }
 
-static int writefd(int fd,char *buf,int len1)
+static void writefd(int fd,char *buf,int len)
 {
-	int len = len1;
+	stats.total_written += len;
 
-	if (!io_buffer) return writefd_unbuffered(fd, buf, len);
+	if (!io_buffer || fd != multiplex_out_fd) {
+		writefd_unbuffered(fd, buf, len);
+		return;
+	}
 
 	while (len) {
 		int n = MIN(len, IO_BUFFER_SIZE-io_buffer_count);
@@ -420,69 +431,42 @@ static int writefd(int fd,char *buf,int len1)
 			io_buffer_count += n;
 		}
 		
-		if (io_buffer_count == IO_BUFFER_SIZE) {
-			if (writefd_unbuffered(fd, io_buffer, 
-					       io_buffer_count) != 
-			    io_buffer_count) {
-				return -1;
-			}
-			io_buffer_count = 0;
-		}
+		if (io_buffer_count == IO_BUFFER_SIZE) io_flush();
 	}
-
-	return len1;
 }
 
 
 void write_int(int f,int32 x)
 {
-  int ret;
-  char b[4];
-  SIVAL(b,0,x);
-  if ((ret=writefd(f,b,4)) != 4) {
-    rprintf(FERROR,"write_int failed : %s\n",
-	    ret==-1?strerror(errno):"EOF");
-    exit_cleanup(1);
-  }
-  total_written += 4;
+	char b[4];
+	SIVAL(b,0,x);
+	writefd(f,b,4);
 }
 
 void write_longint(int f, int64 x)
 {
 	extern int remote_version;
 	char b[8];
-	int ret;
 
 	if (remote_version < 16 || x <= 0x7FFFFFFF) {
 		write_int(f, (int)x);
 		return;
 	}
 
-	write_int(f, -1);
+	write_int(f, (int32)0xFFFFFFFF);
 	SIVAL(b,0,(x&0xFFFFFFFF));
 	SIVAL(b,4,((x>>32)&0xFFFFFFFF));
 
-	if ((ret=writefd(f,b,8)) != 8) {
-		rprintf(FERROR,"write_longint failed : %s\n",
-			ret==-1?strerror(errno):"EOF");
-		exit_cleanup(1);
-	}
-	total_written += 8;
+	writefd(f,b,8);
 }
 
 void write_buf(int f,char *buf,int len)
 {
-  int ret;
-  if ((ret=writefd(f,buf,len)) != len) {
-    rprintf(FERROR,"write_buf failed : %s\n",
-	    ret==-1?strerror(errno):"EOF");
-    exit_cleanup(1);
-  }
-  total_written += len;
+	writefd(f,buf,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));
 }
@@ -493,15 +477,14 @@ void write_byte(int f,unsigned char c)
 	write_buf(f,(char *)&c,1);
 }
 
-void write_flush(int f)
-{
-}
-
-
 int read_line(int f, char *buf, int maxlen)
 {
+	eof_error = 0;
+
 	while (maxlen) {
+		buf[0] = 0;
 		read_buf(f, buf, 1);
+		if (buf[0] == 0) return 0;
 		if (buf[0] == '\n') {
 			buf[0] = 0;
 			break;
@@ -515,6 +498,9 @@ int read_line(int f, char *buf, int maxlen)
 		*buf = 0;
 		return 0;
 	}
+
+	eof_error = 1;
+
 	return 1;
 }
 
@@ -526,10 +512,63 @@ 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);
 }
+
+
+/* setup for multiplexing an error stream with the data stream */
+void io_start_multiplex_out(int fd)
+{
+	multiplex_out_fd = fd;
+	io_flush();
+	io_start_buffering(fd);
+	io_multiplexing_out = 1;
+}
+
+/* setup for multiplexing an error stream with the data stream */
+void io_start_multiplex_in(int fd)
+{
+	multiplex_in_fd = fd;
+	io_flush();
+	io_multiplexing_in = 1;
+}
+
+/* write an message to the multiplexed error stream */
+int io_multiplex_write(int f, 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);
+
+	writefd_unbuffered(multiplex_out_fd, io_buffer-4, len+4);
+	return 1;
+}
+
+/* write a message to the special error fd */
+int io_error_write(int f, char *buf, int len)
+{
+	if (f == -1) return 0;
+	writefd_unbuffered(f, 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;
+}