X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/e92ee12893ca6320f5331384b2c2e8560ca9c88a..b9f592fbf50b0dc9e3d1d33b8deb2bf9abad9ef6:/io.c diff --git a/io.c b/io.c index 2f4162cd..9f9c3823 100644 --- a/io.c +++ b/io.c @@ -1,54 +1,141 @@ -/* - Copyright (C) Andrew Tridgell 1996 - Copyright (C) Paul Mackerras 1996 - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. -*/ +/* -*- c-file-style: "linux" -*- + * + * Copyright (C) 1996-2001 by Andrew Tridgell + * Copyright (C) Paul Mackerras 1996 + * Copyright (C) 2001, 2002 by Martin Pool + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +/** + * @file io.c + * + * Socket and pipe I/O utilities used in rsync. + * + * rsync provides its own multiplexing system, which is used to send + * stderr and stdout over a single socket. We need this because + * stdout normally carries the binary data stream, and stderr all our + * error messages. + * + * For historical reasons this is off during the start of the + * connection, but it's switched on quite early using + * io_start_multiplex_out() and io_start_multiplex_in(). + **/ -/* - socket and pipe IO utilities used in rsync - - tridge, June 1996 - */ #include "rsync.h" -/* if no timeout is specified then use a 60 second select timeout */ +/** 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; -static int multiplex_in_fd; -static int multiplex_out_fd; +static int multiplex_in_fd = -1; +static int multiplex_out_fd = -1; static time_t last_io; -static int eof_error=1; +static int no_flush; + +extern int bwlimit; +extern size_t bwlimit_writemax; extern int verbose; extern int io_timeout; +extern int am_server; +extern int am_daemon; +extern int am_sender; +extern int eol_nulls; +extern int checksum_seed; +extern int protocol_version; +extern char *remote_filesfrom_file; extern struct stats stats; -static int io_error_fd = -1; +const char phase_unknown[] = "unknown"; +int select_timeout = SELECT_TIMEOUT; +int batch_fd = -1; + +/** + * The connection might be dropped at some point; perhaps because the + * remote instance crashed. Just giving the offset on the stream is + * not very helpful. So instead we try to make io_phase_name point to + * something useful. + * + * For buffered/multiplexed I/O these names will be somewhat + * approximate; perhaps for ease of support we would rather make the + * buffer always flush when a single application-level I/O finishes. + * + * @todo Perhaps we want some simple stack functionality, but there's + * no need to overdo it. + **/ +const char *io_write_phase = phase_unknown; +const char *io_read_phase = phase_unknown; + +/** Ignore EOF errors while reading a module listing if the remote + version is 24 or less. */ +int kludge_around_eof = False; + +int msg_fd_in = -1; +int msg_fd_out = -1; + +static int write_batch_monitor_in = -1; +static int write_batch_monitor_out = -1; + +static int io_filesfrom_f_in = -1; +static int io_filesfrom_f_out = -1; +static char io_filesfrom_buf[2048]; +static char *io_filesfrom_bp; +static char io_filesfrom_lastchar; +static int io_filesfrom_buflen; + +static void read_loop(int fd, char *buf, size_t len); + +struct redo_list { + struct redo_list *next; + int num; +}; + +static struct redo_list *redo_list_head; +static struct redo_list *redo_list_tail; + +struct msg_list { + struct msg_list *next; + char *buf; + int len; +}; + +static struct msg_list *msg_list_head; +static struct msg_list *msg_list_tail; -static void read_loop(int fd, char *buf, int len); +static void redo_list_add(int num) +{ + struct redo_list *rl; + + if (!(rl = new(struct redo_list))) + exit_cleanup(RERR_MALLOC); + rl->next = NULL; + rl->num = num; + if (redo_list_tail) + redo_list_tail->next = rl; + else + redo_list_head = rl; + redo_list_tail = rl; +} static void check_timeout(void) { - extern int am_server, am_daemon; time_t t; - - if (!io_timeout) return; + + if (!io_timeout) + return; if (!last_io) { last_io = time(NULL); @@ -59,131 +146,434 @@ 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); } } -/* setup the fd used to propogate errors */ -void io_set_error_fd(int fd) +/** Setup the fd used to receive MSG_* messages. Only needed when + * we're the generator because the sender and receiver both use the + * multiplexed I/O setup. */ +void set_msg_fd_in(int fd) +{ + msg_fd_in = fd; +} + +/** Setup the fd used to send our MSG_* messages. Only needed when + * we're the receiver because the generator and the sender both use + * the multiplexed I/O setup. */ +void set_msg_fd_out(int fd) +{ + msg_fd_out = fd; + set_nonblocking(msg_fd_out); +} + +/* Add a message to the pending MSG_* list. */ +static void msg_list_add(int code, char *buf, int len) { - io_error_fd = fd; + struct msg_list *ml; + + if (!(ml = new(struct msg_list))) + exit_cleanup(RERR_MALLOC); + ml->next = NULL; + if (!(ml->buf = new_array(char, len+4))) + exit_cleanup(RERR_MALLOC); + SIVAL(ml->buf, 0, ((code+MPLEX_BASE)<<24) | len); + memcpy(ml->buf+4, buf, len); + ml->len = len+4; + if (msg_list_tail) + msg_list_tail->next = ml; + else + msg_list_head = ml; + msg_list_tail = ml; } -/* read some data from the error fd and write it to the write log code */ -static void read_error_fd(void) +void send_msg(enum msgcode code, char *buf, int len) { - char buf[200]; - int n; - int fd = io_error_fd; + msg_list_add(code, buf, len); + msg_list_push(NORMAL_FLUSH); +} + +/** Read a message from the MSG_* fd and dispatch it. This is only + * called by the generator. */ +static void read_msg_fd(void) +{ + char buf[2048]; + size_t n; + int fd = msg_fd_in; int tag, len; - io_error_fd = -1; + /* Temporarily disable msg_fd_in. This is needed to avoid looping back + * to this routine from read_timeout() and writefd_unbuffered(). */ + msg_fd_in = -1; read_loop(fd, buf, 4); tag = IVAL(buf, 0); len = tag & 0xFFFFFF; - tag = tag >> 24; - tag -= MPLEX_BASE; + tag = (tag >> 24) - 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; + switch (tag) { + case MSG_DONE: + if (len != 0) { + rprintf(FERROR, "invalid message %d:%d\n", tag, len); + exit_cleanup(RERR_STREAMIO); + } + redo_list_add(-1); + break; + case MSG_REDO: + if (len != 4) { + rprintf(FERROR, "invalid message %d:%d\n", tag, len); + exit_cleanup(RERR_STREAMIO); + } + read_loop(fd, buf, 4); + redo_list_add(IVAL(buf,0)); + break; + case MSG_INFO: + case MSG_ERROR: + case MSG_LOG: + while (len) { + n = len; + if (n >= sizeof buf) + n = sizeof buf - 1; + read_loop(fd, buf, n); + rwrite((enum logcode)tag, buf, n); + len -= n; + } + break; + default: + rprintf(FERROR, "unknown message %d:%d\n", tag, len); + exit_cleanup(RERR_STREAMIO); } - io_error_fd = fd; + msg_fd_in = fd; } +/* Try to push messages off the list onto the wire. If we leave with more + * to do, return 0. On error, return -1. If everything flushed, return 1. + * This is only active in the receiver. */ +int msg_list_push(int flush_it_all) +{ + static int written = 0; + struct timeval tv; + fd_set fds; -static int no_flush; + if (msg_fd_out < 0) + return -1; + + while (msg_list_head) { + struct msg_list *ml = msg_list_head; + int n = write(msg_fd_out, ml->buf + written, ml->len - written); + if (n < 0) { + if (errno == EINTR) + continue; + if (errno != EWOULDBLOCK && errno != EAGAIN) + return -1; + if (!flush_it_all) + return 0; + FD_ZERO(&fds); + FD_SET(msg_fd_out, &fds); + tv.tv_sec = select_timeout; + tv.tv_usec = 0; + if (!select(msg_fd_out+1, NULL, &fds, NULL, &tv)) + check_timeout(); + } else if ((written += n) == ml->len) { + free(ml->buf); + msg_list_head = ml->next; + if (!msg_list_head) + msg_list_tail = NULL; + free(ml); + written = 0; + } + } + return 1; +} + +int get_redo_num(void) +{ + struct redo_list *next; + int num; + + while (!redo_list_head) + read_msg_fd(); + + num = redo_list_head->num; + next = redo_list_head->next; + free(redo_list_head); + redo_list_head = next; + if (!next) + redo_list_tail = NULL; + + return num; +} + +/** + * When we're the receiver and we have a local --files-from list of names + * that needs to be sent over the socket to the sender, we have to do two + * things at the same time: send the sender a list of what files we're + * processing and read the incoming file+info list from the sender. We do + * this by augmenting the read_timeout() function to copy this data. It + * uses the io_filesfrom_buf to read a block of data from f_in (when it is + * ready, since it might be a pipe) and then blast it out f_out (when it + * is ready to receive more data). + */ +void io_set_filesfrom_fds(int f_in, int f_out) +{ + io_filesfrom_f_in = f_in; + io_filesfrom_f_out = f_out; + io_filesfrom_bp = io_filesfrom_buf; + io_filesfrom_lastchar = '\0'; + io_filesfrom_buflen = 0; +} + +/** + * It's almost always an error to get an EOF when we're trying to read + * from the network, because the protocol is self-terminating. + * + * However, there is one unfortunate cases where it is not, which is + * rsync <2.4.6 sending a list of modules on a server, since the list + * is terminated by closing the socket. So, for the section of the + * program where that is a problem (start_socket_client), + * kludge_around_eof is True and we just exit. + */ +static void whine_about_eof(void) +{ + if (kludge_around_eof) + exit_cleanup(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 */ -static int read_timeout(int fd, char *buf, int len) + rprintf(FERROR, RSYNC_NAME ": connection unexpectedly closed " + "(%.0f bytes read so far)\n", + (double)stats.total_read); + + exit_cleanup(RERR_STREAMIO); +} + + +static void die_from_readerr(int err) { - int n, ret=0; + /* this prevents us trying to write errors on a dead socket */ + io_multiplexing_close(); + + rsyserr(FERROR, err, "read error"); + exit_cleanup(RERR_STREAMIO); +} - io_flush(); + +/** + * Read from a socket with I/O 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, size_t len) +{ + int n, ret = 0; + + io_flush(NORMAL_FLUSH); while (ret == 0) { - fd_set fds; + /* until we manage to read *something* */ + fd_set r_fds, w_fds; struct timeval tv; - int fd_count = fd+1; + int maxfd = fd; + int count; - 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; + FD_ZERO(&r_fds); + FD_ZERO(&w_fds); + FD_SET(fd, &r_fds); + if (msg_fd_in >= 0) { + FD_SET(msg_fd_in, &r_fds); + if (msg_fd_in > maxfd) + maxfd = msg_fd_in; + } else if (msg_list_head) { + FD_SET(msg_fd_out, &w_fds); + if (msg_fd_out > maxfd) + maxfd = msg_fd_out; + } + if (io_filesfrom_f_out >= 0) { + int new_fd; + if (io_filesfrom_buflen == 0) { + if (io_filesfrom_f_in >= 0) { + FD_SET(io_filesfrom_f_in, &r_fds); + new_fd = io_filesfrom_f_in; + } else { + io_filesfrom_f_out = -1; + new_fd = -1; + } + } else { + FD_SET(io_filesfrom_f_out, &w_fds); + new_fd = io_filesfrom_f_out; + } + if (new_fd > maxfd) + maxfd = new_fd; } - tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT; + tv.tv_sec = select_timeout; tv.tv_usec = 0; errno = 0; - if (select(fd_count, &fds, NULL, NULL, &tv) < 1) { - if (errno == EBADF) { + count = select(maxfd + 1, &r_fds, &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, &fds)) { - read_error_fd(); + if (msg_fd_in >= 0 && FD_ISSET(msg_fd_in, &r_fds)) + read_msg_fd(); + else if (msg_list_head && FD_ISSET(msg_fd_out, &w_fds)) + msg_list_push(NORMAL_FLUSH); + + if (io_filesfrom_f_out >= 0) { + if (io_filesfrom_buflen) { + if (FD_ISSET(io_filesfrom_f_out, &w_fds)) { + int l = write(io_filesfrom_f_out, + io_filesfrom_bp, + io_filesfrom_buflen); + if (l > 0) { + if (!(io_filesfrom_buflen -= l)) + io_filesfrom_bp = io_filesfrom_buf; + else + io_filesfrom_bp += l; + } else { + /* XXX should we complain? */ + io_filesfrom_f_out = -1; + } + } + } else if (io_filesfrom_f_in >= 0) { + if (FD_ISSET(io_filesfrom_f_in, &r_fds)) { + int l = read(io_filesfrom_f_in, + io_filesfrom_buf, + sizeof io_filesfrom_buf); + if (l <= 0) { + /* Send end-of-file marker */ + io_filesfrom_buf[0] = '\0'; + io_filesfrom_buf[1] = '\0'; + io_filesfrom_buflen = io_filesfrom_lastchar? 2 : 1; + io_filesfrom_f_in = -1; + } else { + if (!eol_nulls) { + char *s = io_filesfrom_buf + l; + /* Transform CR and/or LF into '\0' */ + while (s-- > io_filesfrom_buf) { + if (*s == '\n' || *s == '\r') + *s = '\0'; + } + } + if (!io_filesfrom_lastchar) { + /* Last buf ended with a '\0', so don't + * let this buf start with one. */ + while (l && !*io_filesfrom_bp) + io_filesfrom_bp++, l--; + } + if (!l) + io_filesfrom_bp = io_filesfrom_buf; + else { + char *f = io_filesfrom_bp; + char *t = f; + char *eob = f + l; + /* Eliminate any multi-'\0' runs. */ + while (f != eob) { + if (!(*t++ = *f++)) { + while (f != eob && !*f) + f++, l--; + } + } + io_filesfrom_lastchar = f[-1]; + } + io_filesfrom_buflen = l; + } + } + } } - if (!FD_ISSET(fd, &fds)) continue; + if (!FD_ISSET(fd, &r_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 <= 0) { + if (n == 0) + whine_about_eof(); /* Doesn't return. */ + if (errno == EINTR || errno == EWOULDBLOCK + || errno == EAGAIN) + continue; + die_from_readerr(errno); /* Doesn't return. */ } - if (n == -1 && errno == EINTR) { - continue; - } + buf += n; + len -= n; + ret += n; + if (io_timeout) + last_io = time(NULL); + } - if (n == -1 && - (errno == EWOULDBLOCK || errno == EAGAIN)) { + return ret; +} + +/** + * Read a line into the "fname" buffer (which must be at least MAXPATHLEN + * characters long). + */ +int read_filesfrom_line(int fd, char *fname) +{ + char ch, *s, *eob = fname + MAXPATHLEN - 1; + int cnt; + int reading_remotely = remote_filesfrom_file != NULL; + int nulls = eol_nulls || reading_remotely; + + start: + s = fname; + while (1) { + cnt = read(fd, &ch, 1); + if (cnt < 0 && (errno == EWOULDBLOCK + || errno == EINTR || errno == EAGAIN)) { + struct timeval tv; + fd_set fds; + FD_ZERO(&fds); + FD_SET(fd, &fds); + tv.tv_sec = select_timeout; + tv.tv_usec = 0; + if (!select(fd+1, &fds, NULL, NULL, &tv)) + check_timeout(); continue; } - - - if (n == 0) { - if (eof_error) { - rprintf(FERROR,"unexpected EOF in read_timeout\n"); - } - exit_cleanup(RERR_STREAMIO); + if (cnt != 1) + break; + if (nulls? !ch : (ch == '\r' || ch == '\n')) { + /* Skip empty lines if reading locally. */ + if (!reading_remotely && s == fname) + continue; + break; } - - /* 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); + if (s < eob) + *s++ = ch; } + *s = '\0'; - return ret; + /* Dump comments. */ + if (*fname == '#' || *fname == ';') + goto start; + + return s - fname; } -/* continue trying to read len bytes - don't return until len - has been read */ -static void read_loop(int fd, char *buf, int len) + +/** + * Continue trying to read len bytes - don't return until len has been + * read. + **/ +static void read_loop(int fd, char *buf, size_t len) { while (len) { int n = read_timeout(fd, buf, len); @@ -193,73 +583,108 @@ static void read_loop(int fd, char *buf, int len) } } -/* 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) + +/** + * Read from the file descriptor handling multiplexing - return number + * of bytes read. + * + * Never returns <= 0. + */ +static int readfd_unbuffered(int fd, char *buf, size_t len) { - static int remaining; - int tag, ret=0; + static size_t remaining; + int tag, ret = 0; char line[1024]; + static char *buffer; + static size_t bufferIdx = 0; + static size_t bufferSz; - if (!io_multiplexing_in || fd != multiplex_in_fd) + if (fd != multiplex_in_fd) return read_timeout(fd, buf, len); + if (!io_multiplexing_in && remaining == 0) { + if (!buffer) { + bufferSz = 2 * IO_BUFFER_SIZE; + buffer = new_array(char, bufferSz); + if (!buffer) + out_of_memory("readfd_unbuffered"); + } + remaining = read_timeout(fd, buffer, bufferSz); + bufferIdx = 0; + } + while (ret == 0) { if (remaining) { len = MIN(len, remaining); - read_loop(fd, buf, len); + memcpy(buf, buffer + bufferIdx, len); + bufferIdx += len; remaining -= len; ret = len; - continue; + break; } read_loop(fd, line, 4); tag = IVAL(line, 0); remaining = tag & 0xFFFFFF; - tag = tag >> 24; - - 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); + tag = (tag >> 24) - MPLEX_BASE; + + switch (tag) { + case MSG_DATA: + if (!buffer || remaining > bufferSz) { + buffer = realloc_array(buffer, char, remaining); + if (!buffer) + out_of_memory("readfd_unbuffered"); + bufferSz = remaining; + } + read_loop(fd, buffer, remaining); + bufferIdx = 0; + break; + case MSG_INFO: + case MSG_ERROR: + if (remaining >= sizeof line) { + rprintf(FERROR, "multiplexing overflow %d:%ld\n\n", + tag, (long)remaining); + exit_cleanup(RERR_STREAMIO); + } + read_loop(fd, line, remaining); + rwrite((enum logcode)tag, line, remaining); + remaining = 0; + break; + default: + rprintf(FERROR, "unexpected tag %d\n", tag); exit_cleanup(RERR_STREAMIO); } - - read_loop(fd, line, remaining); - line[remaining] = 0; - - rprintf((enum logcode)tag,"%s", line); - remaining = 0; } + if (remaining == 0) + io_flush(NORMAL_FLUSH); + return ret; } -/* 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) + +/** + * Do a buffered read from @p fd. Don't return until all @p n bytes + * have been read. If all @p n can't be read then exit with an + * error. + **/ +static void readfd(int fd, char *buffer, size_t N) { int ret; - int total=0; - - while (total < N) { - io_flush(); + size_t total = 0; - ret = read_unbuffered(fd,buffer + total,N-total); + while (total < N) { + ret = readfd_unbuffered(fd, buffer + total, N-total); total += ret; } + if (fd == write_batch_monitor_in) { + if ((size_t)write(batch_fd, buffer, total) != total) + exit_cleanup(RERR_FILEIO); + } + stats.total_read += total; } @@ -271,40 +696,37 @@ int32 read_int(int f) readfd(f,b,4); ret = IVAL(b,0); - if (ret == (int32)0xffffffff) return -1; + if (ret == (int32)0xffffffff) + return -1; return ret; } int64 read_longint(int f) { - extern int remote_version; int64 ret; char b[8]; ret = read_int(f); - if ((int32)ret != (int32)0xffffffff) { + 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); - } + 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) +void read_buf(int f,char *buf,size_t len) { readfd(f,buf,len); } -void read_sbuf(int f,char *buf,int len) +void read_sbuf(int f,char *buf,size_t len) { read_buf(f,buf,len); buf[len] = 0; @@ -313,92 +735,148 @@ void read_sbuf(int f,char *buf,int len) unsigned char read_byte(int f) { unsigned char c; - read_buf(f,(char *)&c,1); + read_buf(f, (char *)&c, 1); return c; } -/* write len bytes to fd */ -static void writefd_unbuffered(int fd,char *buf,int len) + +/** + * Sleep after writing to limit I/O bandwidth usage. + * + * @todo Rather than sleeping after each write, it might be better to + * use some kind of averaging. The current algorithm seems to always + * use a bit less bandwidth than specified, because it doesn't make up + * for slow periods. But arguably this is a feature. In addition, we + * ought to take the time used to write the data into account. + * + * During some phases of big transfers (file FOO is uptodate) this is + * called with a small bytes_written every time. As the kernel has to + * round small waits up to guarantee that we actually wait at least the + * requested number of microseconds, this can become grossly inaccurate. + * We therefore keep track of the bytes we've written over time and only + * sleep when the accumulated delay is at least 1 tenth of a second. + **/ +static void sleep_for_bwlimit(int bytes_written) +{ + static struct timeval prior_tv; + static long total_written = 0; + struct timeval tv, start_tv; + long elapsed_usec, sleep_usec; + +#define ONE_SEC 1000000L /* # of microseconds in a second */ + + if (!bwlimit) + return; + + total_written += bytes_written; + + gettimeofday(&start_tv, NULL); + if (prior_tv.tv_sec) { + elapsed_usec = (start_tv.tv_sec - prior_tv.tv_sec) * ONE_SEC + + (start_tv.tv_usec - prior_tv.tv_usec); + total_written -= elapsed_usec * bwlimit / (ONE_SEC/1024); + if (total_written < 0) + total_written = 0; + } + + sleep_usec = total_written * (ONE_SEC/1024) / bwlimit; + if (sleep_usec < ONE_SEC / 10) { + prior_tv = start_tv; + return; + } + + tv.tv_sec = sleep_usec / ONE_SEC; + tv.tv_usec = sleep_usec % ONE_SEC; + select(0, NULL, NULL, NULL, &tv); + + gettimeofday(&prior_tv, NULL); + elapsed_usec = (prior_tv.tv_sec - start_tv.tv_sec) * ONE_SEC + + (prior_tv.tv_usec - start_tv.tv_usec); + total_written = (sleep_usec - elapsed_usec) * bwlimit / (ONE_SEC/1024); +} + + +/** + * Write len bytes to the file descriptor @p fd. + * + * This function underlies the multiplexing system. The body of the + * application never calls this function directly. + **/ +static void writefd_unbuffered(int fd,char *buf,size_t len) { - int total = 0; + size_t n, total = 0; fd_set w_fds, r_fds; - int fd_count, count; + int maxfd, count, ret; struct timeval tv; + if (fd == msg_fd_out) { + rprintf(FERROR, "Internal error: wrong write used in receiver.\n"); + exit_cleanup(RERR_PROTOCOL); + } + no_flush++; while (total < len) { FD_ZERO(&w_fds); - FD_ZERO(&r_fds); FD_SET(fd,&w_fds); - fd_count = fd; + maxfd = fd; - if (io_error_fd != -1) { - FD_SET(io_error_fd,&r_fds); - if (io_error_fd > fd_count) - fd_count = io_error_fd; + if (msg_fd_in >= 0) { + FD_ZERO(&r_fds); + FD_SET(msg_fd_in,&r_fds); + if (msg_fd_in > maxfd) + maxfd = msg_fd_in; } - tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT; + tv.tv_sec = select_timeout; tv.tv_usec = 0; errno = 0; - - count = select(fd_count+1, - io_error_fd != -1?&r_fds:NULL, - &w_fds,NULL, - &tv); + count = select(maxfd + 1, msg_fd_in >= 0 ? &r_fds : NULL, + &w_fds, NULL, &tv); if (count <= 0) { - if (errno == EBADF) { + if (count < 0 && 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 (msg_fd_in >= 0 && FD_ISSET(msg_fd_in, &r_fds)) + read_msg_fd(); - if (FD_ISSET(fd, &w_fds)) { - int ret, n = len-total; - - ret = write(fd,buf+total,n); + if (!FD_ISSET(fd, &w_fds)) + continue; - if (ret == -1 && errno == EINTR) { - continue; + n = len - total; + if (bwlimit && n > bwlimit_writemax) + n = bwlimit_writemax; + ret = write(fd, buf + total, n); + + if (ret <= 0) { + if (ret < 0) { + if (errno == EINTR) + continue; + if (errno == EWOULDBLOCK || errno == EAGAIN) { + msleep(1); + continue; + } } - if (ret == -1 && - (errno == EWOULDBLOCK || errno == EAGAIN)) { - msleep(1); - continue; - } + /* Don't try to write errors back across the stream. */ + io_multiplexing_close(); + rsyserr(FERROR, errno, + "writefd_unbuffered failed to write %ld bytes: phase \"%s\"", + (long)len, io_write_phase); + exit_cleanup(RERR_STREAMIO); + } - if (ret <= 0) { - rprintf(FERROR,"erroring writing %d bytes - exiting\n", len); - exit_cleanup(RERR_STREAMIO); - } + sleep_for_bwlimit(ret); - /* 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); - } + total += ret; + + if (io_timeout) + last_io = time(NULL); } no_flush--; @@ -408,27 +886,35 @@ static void writefd_unbuffered(int fd,char *buf,int len) static char *io_buffer; static int io_buffer_count; -void io_start_buffering(int fd) +void io_start_buffering_out(int fd) { - if (io_buffer) return; + if (io_buffer) + return; multiplex_out_fd = fd; - io_buffer = (char *)malloc(IO_BUFFER_SIZE); - if (!io_buffer) out_of_memory("writefd"); + io_buffer = new_array(char, 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) +void io_start_buffering_in(int fd) +{ + multiplex_in_fd = fd; +} + +/** + * Write an message to a multiplexed stream. If this fails then rsync + * exits. + **/ +static void mplex_write(int fd, enum msgcode code, char *buf, size_t len) { char buffer[4096]; - int n = len; + size_t n = len; SIVAL(buffer, 0, ((MPLEX_BASE + (int)code)<<24) + len); - if (n > (sizeof(buffer)-4)) { - n = sizeof(buffer)-4; - } + if (n > sizeof buffer - 4) + n = sizeof buffer - 4; memcpy(&buffer[4], buf, n); writefd_unbuffered(fd, buffer, n+4); @@ -436,48 +922,50 @@ static void mplex_write(int fd, enum logcode code, char *buf, int len) len -= n; buf += n; - if (len) { + if (len) writefd_unbuffered(fd, buf, len); - } } -void io_flush(void) +void io_flush(int flush_it_all) { int fd = multiplex_out_fd; - if (!io_buffer_count || no_flush) return; - if (io_multiplexing_out) { - mplex_write(fd, FNONE, io_buffer, io_buffer_count); - } else { + msg_list_push(flush_it_all); + + if (!io_buffer_count || no_flush) + return; + + if (io_multiplexing_out) + mplex_write(fd, MSG_DATA, io_buffer, io_buffer_count); + else writefd_unbuffered(fd, io_buffer, io_buffer_count); - } io_buffer_count = 0; } -void io_end_buffering(int fd) + +void io_end_buffering(void) { - io_flush(); + io_flush(NORMAL_FLUSH); if (!io_multiplexing_out) { 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) +static void writefd(int fd,char *buf,size_t len) { - 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; -} + stats.total_written += len; + if (fd == msg_fd_out) { + rprintf(FERROR, "Internal error: wrong write used in receiver.\n"); + exit_cleanup(RERR_PROTOCOL); + } -static void writefd(int fd,char *buf,int len) -{ - stats.total_written += len; + if (fd == write_batch_monitor_out) { + if ((size_t)write(batch_fd, buf, len) != len) + exit_cleanup(RERR_FILEIO); + } if (!io_buffer || fd != multiplex_out_fd) { writefd_unbuffered(fd, buf, len); @@ -485,15 +973,16 @@ static void writefd(int fd,char *buf,int len) } while (len) { - int n = MIN(len, IO_BUFFER_SIZE-io_buffer_count); + int n = MIN((int)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 (io_buffer_count == IO_BUFFER_SIZE) + io_flush(NORMAL_FLUSH); } } @@ -505,29 +994,46 @@ void write_int(int f,int32 x) writefd(f,b,4); } + +void write_int_named(int f, int32 x, const char *phase) +{ + io_write_phase = phase; + write_int(f, x); + io_write_phase = phase_unknown; +} + + +/* + * 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; char b[8]; - if (remote_version < 16 || x <= 0x7FFFFFFF) { + if (x <= 0x7FFFFFFF) { write_int(f, (int)x); return; } +#ifdef NO_INT64 + rprintf(FERROR,"Integer overflow - attempted 64 bit offset\n"); + exit_cleanup(RERR_UNSUPPORTED); +#else write_int(f, (int32)0xFFFFFFFF); SIVAL(b,0,(x&0xFFFFFFFF)); SIVAL(b,4,((x>>32)&0xFFFFFFFF)); writefd(f,b,8); +#endif } -void write_buf(int f,char *buf,int len) +void write_buf(int f,char *buf,size_t len) { writefd(f,buf,len); } -/* write a string to the connection */ +/** Write a string to the connection */ static void write_sbuf(int f,char *buf) { write_buf(f, buf, strlen(buf)); @@ -539,89 +1045,105 @@ void write_byte(int f,unsigned char c) write_buf(f,(char *)&c,1); } -int read_line(int f, char *buf, int maxlen) -{ - eof_error = 0; + +/** + * Read a line of up to @p maxlen characters into @p buf (not counting + * the trailing null). Strips the (required) trailing newline and all + * carriage returns. + * + * @return 1 for success; 0 for I/O error or truncation. + **/ +int read_line(int f, char *buf, size_t maxlen) +{ while (maxlen) { buf[0] = 0; read_buf(f, buf, 1); - if (buf[0] == 0) return 0; - if (buf[0] == '\n') { - buf[0] = 0; + if (buf[0] == 0) + return 0; + if (buf[0] == '\n') break; - } if (buf[0] != '\r') { buf++; maxlen--; } } - if (maxlen == 0) { - *buf = 0; - return 0; - } - - eof_error = 1; - - return 1; + *buf = '\0'; + return maxlen > 0; } void io_printf(int fd, const char *format, ...) { - va_list ap; + va_list ap; char buf[1024]; 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); + if (len < 0) + exit_cleanup(RERR_STREAMIO); write_sbuf(fd, buf); } -/* setup for multiplexing an error stream with the data stream */ +/** Setup for multiplexing a MSG_* stream with the data stream. */ void io_start_multiplex_out(int fd) { multiplex_out_fd = fd; - io_flush(); - io_start_buffering(fd); + io_flush(NORMAL_FLUSH); + io_start_buffering_out(fd); io_multiplexing_out = 1; } -/* setup for multiplexing an error stream with the data stream */ +/** Setup for multiplexing a MSG_* stream with the data stream. */ void io_start_multiplex_in(int fd) { multiplex_in_fd = fd; - io_flush(); + io_flush(NORMAL_FLUSH); io_multiplexing_in = 1; } -/* write an message to the multiplexed error stream */ -int io_multiplex_write(enum logcode code, char *buf, int len) +/** Write an message to the multiplexed data stream. */ +int io_multiplex_write(enum msgcode code, char *buf, size_t len) { - if (!io_multiplexing_out) return 0; + if (!io_multiplexing_out) + return 0; - io_flush(); + io_flush(NORMAL_FLUSH); stats.total_written += (len+4); mplex_write(multiplex_out_fd, code, buf, len); return 1; } -/* write a message to the special error fd */ -int io_error_write(int f, enum logcode code, char *buf, int len) +/** Stop output multiplexing. */ +void io_multiplexing_close(void) { - if (f == -1) return 0; - mplex_write(f, code, buf, len); - return 1; + io_multiplexing_out = 0; } -/* stop output multiplexing */ -void io_multiplexing_close(void) +void start_write_batch(int fd) { - io_multiplexing_out = 0; + /* Some communication has already taken place, but we don't + * enable batch writing until here so that we can write a + * canonical record of the communication even though the + * actual communication so far depends on whether a daemon + * is involved. */ + write_int(batch_fd, protocol_version); + write_int(batch_fd, checksum_seed); + stats.total_written -= sizeof (int) * 2; + + if (am_sender) + write_batch_monitor_out = fd; + else + write_batch_monitor_in = fd; } +void stop_write_batch(void) +{ + write_batch_monitor_out = -1; + write_batch_monitor_in = -1; +}