X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/58d433ab3cbf7dd3010a0944dc579756dfd89ad7..08f15335b5b469b29cbdacd0fc5ba48d76acf280:/io.c

diff --git a/io.c b/io.c
index 22e5b3db..6f3854e3 100644
--- a/io.c
+++ b/io.c
@@ -18,205 +18,557 @@
 */
 
 /*
-  Utilities used in rsync 
+  socket and pipe IO utilities used in rsync 
 
   tridge, June 1996
   */
 #include "rsync.h"
 
-static int total_written = 0;
-static int total_read = 0;
+/* 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 io_timeout;
+extern struct stats stats;
 
-int write_total(void)
+static int buffer_f_in = -1;
+static int io_error_fd = -1;
+
+void setup_readbuffer(int f_in)
 {
-  return total_written;
+	buffer_f_in = f_in;
 }
 
-int read_total(void)
+static void check_timeout(void)
 {
-  return total_read;
+	time_t t;
+	
+	if (!io_timeout) return;
+
+	if (!last_io) {
+		last_io = time(NULL);
+		return;
+	}
+
+	t = time(NULL);
+
+	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);
+	}
 }
 
-static int buffer_f_in = -1;
+/* setup the fd used to propogate errors */
+void io_set_error_fd(int fd)
+{
+	io_error_fd = fd;
+}
 
-void setup_nonblocking(int f_in,int f_out)
+/* read some data from the error fd and write it to FERROR */
+static void read_error_fd(void)
 {
-  set_blocking(f_out,0);
-  buffer_f_in = f_in;
+	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);
+	}
+
+	io_error_fd = fd;
 }
 
 
-static char *read_buffer = NULL;
-static char *read_buffer_p = NULL;
-static int read_buffer_len = 0;
-static int read_buffer_size = 0;
+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, ret=0;
+
+	io_flush();
+
+	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;
+
+		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) {
+			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);
+	}
 
-/* 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)
+	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)
+{
+	while (len) {
+		int n = read_timeout(fd, buf, len);
+
+		buf += n;
+		len -= n;
+	}
+}
+
+/* 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)
 {
-  int n;
+	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;
+		}
+
+		read_loop(fd, ibuf, 4);
+		tag = IVAL(ibuf, 0);
+
+		remaining = tag & 0xFFFFFF;
+		tag = tag >> 24;
+
+		if (tag == MPLEX_BASE) continue;
 
-  if (read_buffer_len == 0) {
-    read_buffer_p = read_buffer;
-  }
+		tag -= MPLEX_BASE;
 
-  if ((n=num_waiting(f)) <= 0)
-    return;
+		if (tag != FERROR && tag != FINFO) {
+			rprintf(FERROR,"unexpected tag %d\n", tag);
+			exit_cleanup(RERR_STREAMIO);
+		}
 
-  if (read_buffer_p != read_buffer) {
-    memmove(read_buffer,read_buffer_p,read_buffer_len);
-    read_buffer_p = read_buffer;
-  }
+		if (remaining > sizeof(line)-1) {
+			rprintf(FERROR,"multiplexing overflow %d\n\n", 
+				remaining);
+			exit_cleanup(RERR_STREAMIO);
+		}
 
-  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;      
-  }
+		read_loop(fd, line, remaining);
+		line[remaining] = 0;
 
-  n = read(f,read_buffer+read_buffer_len,n);
-  if (n > 0) {
-    read_buffer_len += n;
-  }
+		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;  
- 
-  while (total < N)
-    {
-      if (read_buffer_len > 0) {
-	ret = MIN(read_buffer_len,N-total);
-	memcpy(buffer+total,read_buffer_p,ret);
-	read_buffer_p += ret;
-	read_buffer_len -= ret;
-      } else {
-	ret = read(fd,buffer + total,N - total);
-      }
+	int  ret;
+	int total=0;  
+	
+	while (total < N) {
+		io_flush();
+
+		ret = read_unbuffered(fd,buffer + total,N-total);
+		total += ret;
+	}
 
-      if (ret <= 0)
-	return total;
-      total += ret;
-    }
-  return total;
+	stats.total_read += total;
 }
 
 
-int read_int(int f)
+int32 read_int(int f)
+{
+	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)
 {
-  char b[4];
-  if (readfd(f,b,4) != 4) {
-    if (verbose > 1) 
-      fprintf(stderr,"Error reading %d bytes : %s\n",4,strerror(errno));
-    exit(1);
-  }
-  total_read += 4;
-  return IVAL(b,0);
+	extern int remote_version;
+	int64 ret;
+	char b[8];
+	ret = read_int(f);
+
+	if ((int32)ret != (int32)0xffffffff) {
+		return ret;
+	}
+
+#ifdef NO_INT64
+	rprintf(FERROR,"Integer overflow - attempted 64 bit offset\n");
+	exit_cleanup(RERR_UNSUPPORTED);
+#else
+	if (remote_version >= 16) {
+		readfd(f,b,8);
+		ret = IVAL(b,0) | (((int64)IVAL(b,4))<<32);
+	}
+#endif
+
+	return ret;
 }
 
 void read_buf(int f,char *buf,int len)
 {
-  if (readfd(f,buf,len) != len) {
-    if (verbose > 1) 
-      fprintf(stderr,"Error reading %d bytes : %s\n",len,strerror(errno));
-    exit(1);
-  }
-  total_read += len;
+	readfd(f,buf,len);
 }
 
+void read_sbuf(int f,char *buf,int len)
+{
+	read_buf(f,buf,len);
+	buf[len] = 0;
+}
 
-int read_write(int fd_in,int fd_out,int size)
+unsigned char read_byte(int f)
 {
-  static char *buf=NULL;
-  static int bufsize = WRITE_BLOCK_SIZE;
-  int total=0;
-  
-  if (!buf) {
-    buf = (char *)malloc(bufsize);
-    if (!buf) out_of_memory("read_write");
-  }
+	unsigned char c;
+	read_buf(f,(char *)&c,1);
+	return c;
+}
+
+
 
-  while (total < size) {
-    int n = MIN(size-total,bufsize);
-    read_buf(fd_in,buf,n);
-    if (write(fd_out,buf,n) != n)
-      return total;
-    total += n;
-  }
-  return total;
+/* 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)
+{
+	int total = 0;
+	fd_set w_fds, r_fds;
+	int fd_count, count;
+	struct timeval tv;
+
+	no_flush++;
+
+	while (total < len) {
+		FD_ZERO(&w_fds);
+		FD_ZERO(&r_fds);
+		FD_SET(fd,&w_fds);
+		fd_count = fd;
+
+		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;
+
+		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 (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) {
+				continue;
+			}
+
+			if (ret <= 0) {
+				rprintf(FERROR,"erroring writing %d bytes - exiting\n", len);
+				exit_cleanup(RERR_STREAMIO);
+			}
+
+			total += ret;
+
+			if (io_timeout)
+				last_io = time(NULL);
+		}
+	}
+
+	no_flush--;
+}
+
+
+static char *io_buffer;
+static int io_buffer_count;
+
+void io_start_buffering(int fd)
+{
+	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)
+{
+	io_flush();
+	if (!io_multiplexing_out) {
+		free(io_buffer-4);
+		io_buffer = NULL;
+	}
+}
 
-static int writefd(int fd,char *buf,int len)
+static void writefd(int fd,char *buf,int len)
 {
-  int total = 0;
-  fd_set fds;
-  struct timeval tv;
+	stats.total_written += 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);
+		if (n > 0) {
+			memcpy(io_buffer+io_buffer_count, buf, n);
+			buf += n;
+			len -= n;
+			io_buffer_count += n;
+		}
+		
+		if (io_buffer_count == IO_BUFFER_SIZE) io_flush();
+	}
+}
 
-  if (buffer_f_in == -1) 
-    return write(fd,buf,len);
 
-  while (total < len) {
-    int ret = write(fd,buf+total,len-total);
+void write_int(int f,int32 x)
+{
+	char b[4];
+	SIVAL(b,0,x);
+	writefd(f,b,4);
+}
 
-    if (ret == 0) return total;
+void write_longint(int f, int64 x)
+{
+	extern int remote_version;
+	char b[8];
 
-    if (ret == -1 && errno != EWOULDBLOCK) 
-      return total?total:-1;
+	if (remote_version < 16 || x <= 0x7FFFFFFF) {
+		write_int(f, (int)x);
+		return;
+	}
 
-    if (ret == -1) {
-      read_check(buffer_f_in);
+	write_int(f, (int32)0xFFFFFFFF);
+	SIVAL(b,0,(x&0xFFFFFFFF));
+	SIVAL(b,4,((x>>32)&0xFFFFFFFF));
 
-      FD_ZERO(&fds);
-      FD_SET(fd,&fds);
-      tv.tv_sec = BLOCKING_TIMEOUT;
-      tv.tv_usec = 0;
-      select(16,NULL,&fds,NULL,&tv);
-    } else {
-      total += ret;
-    }
-  }
+	writefd(f,b,8);
+}
 
-  return total;
+void write_buf(int f,char *buf,int len)
+{
+	writefd(f,buf,len);
 }
 
+/* write a string to the connection */
+static void write_sbuf(int f,char *buf)
+{
+	write_buf(f, buf, strlen(buf));
+}
 
 
-void write_int(int f,int x)
+void write_byte(int f,unsigned char c)
 {
-  char b[4];
-  SIVAL(b,0,x);
-  if (writefd(f,b,4) != 4) {
-    fprintf(stderr,"write_int failed : %s\n",strerror(errno));
-    exit(1);
-  }
-  total_written += 4;
+	write_buf(f,(char *)&c,1);
 }
 
-void write_buf(int f,char *buf,int len)
+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;
+		}
+		if (buf[0] != '\r') {
+			buf++;
+			maxlen--;
+		}
+	}
+	if (maxlen == 0) {
+		*buf = 0;
+		return 0;
+	}
+
+	eof_error = 1;
+
+	return 1;
+}
+
+
+void io_printf(int fd, const char *format, ...)
+{
+	va_list ap;  
+	char buf[1024];
+	int len;
+	
+	va_start(ap, format);
+	len = vslprintf(buf, sizeof(buf), format, ap);
+	va_end(ap);
+
+	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)
 {
-  if (writefd(f,buf,len) != len) {
-    fprintf(stderr,"write_buf failed : %s\n",strerror(errno));
-    exit(1);
-  }
-  total_written += len;
+	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();
 
-void write_flush(int f)
+	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;
+}