/* * Socket and pipe I/O utilities used in rsync. * * Copyright (C) 1996-2001 Andrew Tridgell * Copyright (C) 1996 Paul Mackerras * Copyright (C) 2001, 2002 Martin Pool * Copyright (C) 2003, 2004, 2005, 2006 Wayne Davison * * 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., * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ /* Rsync provides its own multiplexing system, which is used to send * stderr and stdout over a single socket. * * 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(). */ #include "rsync.h" /** If no timeout is specified then use a 60 second select timeout */ #define SELECT_TIMEOUT 60 extern int bwlimit; extern size_t bwlimit_writemax; extern int io_timeout; extern int allowed_lull; extern int am_server; extern int am_daemon; extern int am_sender; extern int am_generator; extern int eol_nulls; extern int read_batch; extern int csum_length; extern int checksum_seed; extern int protocol_version; extern int remove_source_files; extern int preserve_hard_links; extern char *filesfrom_host; extern struct stats stats; extern struct file_list *the_file_list; const char phase_unknown[] = "unknown"; int ignore_timeout = 0; int batch_fd = -1; int batch_gen_fd = -1; /* Ignore an EOF error if non-zero. See whine_about_eof(). */ int kluge_around_eof = 0; int msg_fd_in = -1; int msg_fd_out = -1; int sock_f_in = -1; int sock_f_out = -1; static int io_multiplexing_out; static int io_multiplexing_in; static time_t last_io_in; static time_t last_io_out; static int no_flush; 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 int defer_forwarding_messages = 0; static int select_timeout = SELECT_TIMEOUT; static int active_filecnt = 0; static OFF_T active_bytecnt = 0; static char int_byte_cnt[256] = { 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 00 - 0F */ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 10 - 1F */ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 20 - 2F */ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 30 - 3F */ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 40 - 4F */ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 50 - 5F */ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 60 - 6F */ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 70 - 7F */ 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, /* 80 - 8F */ 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, /* 90 - 9F */ 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, /* A0 - AF */ 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, /* B0 - BF */ 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, /* C0 - CF */ 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, /* D0 - DF */ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, /* E0 - EF */ 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, /* F0 - FF */ }; static void read_loop(int fd, char *buf, size_t len); struct flist_ndx_item { struct flist_ndx_item *next; int ndx; }; struct flist_ndx_list { struct flist_ndx_item *head, *tail; }; static struct flist_ndx_list redo_list, hlink_list; struct msg_list_item { struct msg_list_item *next; int len; char buf[1]; }; struct msg_list { struct msg_list_item *head, *tail; }; static struct msg_list msg2genr, msg2sndr; static void flist_ndx_push(struct flist_ndx_list *lp, int ndx) { struct flist_ndx_item *item; if (!(item = new(struct flist_ndx_item))) out_of_memory("flist_ndx_push"); item->next = NULL; item->ndx = ndx; if (lp->tail) lp->tail->next = item; else lp->head = item; lp->tail = item; } static int flist_ndx_pop(struct flist_ndx_list *lp) { struct flist_ndx_item *next; int ndx; if (!lp->head) return -1; ndx = lp->head->ndx; next = lp->head->next; free(lp->head); lp->head = next; if (!next) lp->tail = NULL; return ndx; } static void check_timeout(void) { time_t t; if (!io_timeout || ignore_timeout) return; if (!last_io_in) { last_io_in = time(NULL); return; } t = time(NULL); if (t - last_io_in >= io_timeout) { if (!am_server && !am_daemon) { rprintf(FERROR, "io timeout after %d seconds -- exiting\n", (int)(t-last_io_in)); } exit_cleanup(RERR_TIMEOUT); } } /* Note the fds used for the main socket (which might really be a pipe * for a local transfer, but we can ignore that). */ void io_set_sock_fds(int f_in, int f_out) { sock_f_in = f_in; sock_f_out = f_out; } void set_io_timeout(int secs) { io_timeout = secs; if (!io_timeout || io_timeout > SELECT_TIMEOUT) select_timeout = SELECT_TIMEOUT; else select_timeout = io_timeout; allowed_lull = read_batch ? 0 : (io_timeout + 1) / 2; } /* Setup the fd used to receive MSG_* messages. Only needed during the * early stages of being a local sender (up through the sending of the * file list) or when we're the generator (to fetch the messages from * the receiver). */ 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 (to send our messages to the generator). */ 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(struct msg_list *lst, int code, const char *buf, int len) { struct msg_list_item *m; int sz = len + 4 + sizeof m[0] - 1; if (!(m = (struct msg_list_item *)new_array(char, sz))) out_of_memory("msg_list_add"); m->next = NULL; m->len = len + 4; SIVAL(m->buf, 0, ((code+MPLEX_BASE)<<24) | len); memcpy(m->buf + 4, buf, len); if (lst->tail) lst->tail->next = m; else lst->head = m; lst->tail = m; } /* Read a message from the MSG_* fd and handle it. This is called either * during the early stages of being a local sender (up through the sending * of the file list) or when we're the generator (to fetch the messages * from the receiver). */ static void read_msg_fd(void) { char buf[2048]; size_t n; int fd = msg_fd_in; int tag, len; /* Temporarily disable msg_fd_in. This is needed to avoid looping back * to this routine from writefd_unbuffered(). */ msg_fd_in = -1; read_loop(fd, buf, 4); tag = IVAL(buf, 0); len = tag & 0xFFFFFF; tag = (tag >> 24) - MPLEX_BASE; switch (tag) { case MSG_DONE: if (len != 0 || !am_generator) { rprintf(FERROR, "invalid message %d:%d\n", tag, len); exit_cleanup(RERR_STREAMIO); } flist_ndx_push(&redo_list, -1); break; case MSG_REDO: if (len != 4 || !am_generator) { rprintf(FERROR, "invalid message %d:%d\n", tag, len); exit_cleanup(RERR_STREAMIO); } read_loop(fd, buf, 4); if (remove_source_files) decrement_active_files(IVAL(buf,0)); flist_ndx_push(&redo_list, IVAL(buf,0)); break; case MSG_DELETED: if (len >= (int)sizeof buf || !am_generator) { rprintf(FERROR, "invalid message %d:%d\n", tag, len); exit_cleanup(RERR_STREAMIO); } read_loop(fd, buf, len); send_msg(MSG_DELETED, buf, len); break; case MSG_SUCCESS: if (len != 4 || !am_generator) { rprintf(FERROR, "invalid message %d:%d\n", tag, len); exit_cleanup(RERR_STREAMIO); } read_loop(fd, buf, len); if (remove_source_files) { decrement_active_files(IVAL(buf,0)); send_msg(MSG_SUCCESS, buf, len); } if (preserve_hard_links) flist_ndx_push(&hlink_list, IVAL(buf,0)); break; case MSG_SOCKERR: case MSG_CLIENT: if (!am_generator) { rprintf(FERROR, "invalid message %d:%d\n", tag, len); exit_cleanup(RERR_STREAMIO); } if (tag == MSG_SOCKERR) close_multiplexing_out(); /* FALL THROUGH */ 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 [%s]\n", tag, len, who_am_i()); exit_cleanup(RERR_STREAMIO); } msg_fd_in = fd; } /* This is used by the generator to limit how many file transfers can * be active at once when --remove-source-files is specified. Without * this, sender-side deletions were mostly happening at the end. */ void increment_active_files(int ndx, int itemizing, enum logcode code) { /* TODO: tune these limits? */ while (active_filecnt >= (active_bytecnt >= 128*1024 ? 10 : 50)) { #ifdef SUPPORT_HARD_LINKS if (hlink_list.head) check_for_finished_hlinks(itemizing, code); #endif read_msg_fd(); } active_filecnt++; active_bytecnt += F_LENGTH(the_file_list->files[ndx]); } void decrement_active_files(int ndx) { active_filecnt--; active_bytecnt -= F_LENGTH(the_file_list->files[ndx]); } /* 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. */ static int msg2genr_flush(int flush_it_all) { static int written = 0; struct timeval tv; fd_set fds; if (msg_fd_out < 0) return -1; while (msg2genr.head) { struct msg_list_item *m = msg2genr.head; int n = write(msg_fd_out, m->buf + written, m->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) == m->len) { msg2genr.head = m->next; if (!msg2genr.head) msg2genr.tail = NULL; free(m); written = 0; } } return 1; } int send_msg(enum msgcode code, const char *buf, int len) { if (msg_fd_out < 0) { if (!defer_forwarding_messages) return io_multiplex_write(code, buf, len); if (!io_multiplexing_out) return 0; msg_list_add(&msg2sndr, code, buf, len); return 1; } msg_list_add(&msg2genr, code, buf, len); msg2genr_flush(NORMAL_FLUSH); return 1; } void send_msg_int(enum msgcode code, int num) { char numbuf[4]; SIVAL(numbuf, 0, num); send_msg(code, numbuf, 4); } int get_redo_num(int itemizing, enum logcode code) { while (1) { #ifdef SUPPORT_HARD_LINKS if (hlink_list.head) check_for_finished_hlinks(itemizing, code); #endif if (redo_list.head) break; read_msg_fd(); } return flist_ndx_pop(&redo_list); } int get_hlink_num(void) { return flist_ndx_pop(&hlink_list); } /** * 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 (for the most part) self-terminating. * * There is one case for the receiver when it is at the end of the transfer * (hanging around reading any keep-alive packets that might come its way): if * the sender dies before the generator's kill-signal comes through, we can end * up here needing to loop until the kill-signal arrives. In this situation, * kluge_around_eof will be < 0. * * There is another case for older protocol versions (< 24) where the module * listing was not terminated, so we must ignore an EOF error in that case and * exit. In this situation, kluge_around_eof will be > 0. */ static void whine_about_eof(int fd) { if (kluge_around_eof && fd == sock_f_in) { int i; if (kluge_around_eof > 0) exit_cleanup(0); /* If we're still here after 10 seconds, exit with an error. */ for (i = 10*1000/20; i--; ) msleep(20); } rprintf(FERROR, RSYNC_NAME ": connection unexpectedly closed " "(%.0f bytes received so far) [%s]\n", (double)stats.total_read, who_am_i()); exit_cleanup(RERR_STREAMIO); } /** * 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, cnt = 0; io_flush(NORMAL_FLUSH); while (cnt == 0) { /* until we manage to read *something* */ fd_set r_fds, w_fds; struct timeval tv; int maxfd = fd; int count; FD_ZERO(&r_fds); FD_ZERO(&w_fds); FD_SET(fd, &r_fds); if (msg2genr.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 = select_timeout; tv.tv_usec = 0; errno = 0; count = select(maxfd + 1, &r_fds, &w_fds, NULL, &tv); if (count <= 0) { if (errno == EBADF) exit_cleanup(RERR_SOCKETIO); check_timeout(); continue; } if (msg2genr.head && FD_ISSET(msg_fd_out, &w_fds)) msg2genr_flush(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, &r_fds)) continue; n = read(fd, buf, len); if (n <= 0) { if (n == 0) whine_about_eof(fd); /* Doesn't return. */ if (errno == EINTR || errno == EWOULDBLOCK || errno == EAGAIN) continue; /* Don't write errors on a dead socket. */ if (fd == sock_f_in) { close_multiplexing_out(); rsyserr(FSOCKERR, errno, "read error"); } else rsyserr(FERROR, errno, "read error"); exit_cleanup(RERR_STREAMIO); } buf += n; len -= n; cnt += n; if (fd == sock_f_in && io_timeout) last_io_in = time(NULL); } return cnt; } /** * 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 = filesfrom_host != 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 r_fds, e_fds; FD_ZERO(&r_fds); FD_SET(fd, &r_fds); FD_ZERO(&e_fds); FD_SET(fd, &e_fds); tv.tv_sec = select_timeout; tv.tv_usec = 0; if (!select(fd+1, &r_fds, NULL, &e_fds, &tv)) check_timeout(); if (FD_ISSET(fd, &e_fds)) { rsyserr(FINFO, errno, "select exception on fd %d", fd); } continue; } if (cnt != 1) break; if (nulls? !ch : (ch == '\r' || ch == '\n')) { /* Skip empty lines if reading locally. */ if (!reading_remotely && s == fname) continue; break; } if (s < eob) *s++ = ch; } *s = '\0'; /* Dump comments. */ if (*fname == '#' || *fname == ';') goto start; return s - fname; } static char *iobuf_out; static int iobuf_out_cnt; void io_start_buffering_out(void) { if (iobuf_out) return; if (!(iobuf_out = new_array(char, IO_BUFFER_SIZE))) out_of_memory("io_start_buffering_out"); iobuf_out_cnt = 0; } static char *iobuf_in; static size_t iobuf_in_siz; void io_start_buffering_in(void) { if (iobuf_in) return; iobuf_in_siz = 2 * IO_BUFFER_SIZE; if (!(iobuf_in = new_array(char, iobuf_in_siz))) out_of_memory("io_start_buffering_in"); } void io_end_buffering(void) { io_flush(NORMAL_FLUSH); if (!io_multiplexing_out) { free(iobuf_out); iobuf_out = NULL; } } void maybe_flush_socket(void) { if (iobuf_out && iobuf_out_cnt && time(NULL) - last_io_out >= 5) io_flush(NORMAL_FLUSH); } void maybe_send_keepalive(void) { if (time(NULL) - last_io_out >= allowed_lull) { if (!iobuf_out || !iobuf_out_cnt) { if (protocol_version < 29) return; /* there's nothing we can do */ write_int(sock_f_out, the_file_list->count); write_shortint(sock_f_out, ITEM_IS_NEW); } if (iobuf_out) io_flush(NORMAL_FLUSH); } } /** * 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); buf += n; len -= n; } } /** * 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 size_t remaining; static size_t iobuf_in_ndx; size_t msg_bytes; int tag, cnt = 0; char line[BIGPATHBUFLEN]; if (!iobuf_in || fd != sock_f_in) return read_timeout(fd, buf, len); if (!io_multiplexing_in && remaining == 0) { remaining = read_timeout(fd, iobuf_in, iobuf_in_siz); iobuf_in_ndx = 0; } while (cnt == 0) { if (remaining) { len = MIN(len, remaining); memcpy(buf, iobuf_in + iobuf_in_ndx, len); iobuf_in_ndx += len; remaining -= len; cnt = len; break; } read_loop(fd, line, 4); tag = IVAL(line, 0); msg_bytes = tag & 0xFFFFFF; tag = (tag >> 24) - MPLEX_BASE; switch (tag) { case MSG_DATA: if (msg_bytes > iobuf_in_siz) { if (!(iobuf_in = realloc_array(iobuf_in, char, msg_bytes))) out_of_memory("readfd_unbuffered"); iobuf_in_siz = msg_bytes; } read_loop(fd, iobuf_in, msg_bytes); remaining = msg_bytes; iobuf_in_ndx = 0; break; case MSG_DELETED: if (msg_bytes >= sizeof line) goto overflow; read_loop(fd, line, msg_bytes); /* A directory name was sent with the trailing null */ if (msg_bytes > 0 && !line[msg_bytes-1]) log_delete(line, S_IFDIR); else { line[msg_bytes] = '\0'; log_delete(line, S_IFREG); } break; case MSG_SUCCESS: if (msg_bytes != 4) { rprintf(FERROR, "invalid multi-message %d:%ld [%s]\n", tag, (long)msg_bytes, who_am_i()); exit_cleanup(RERR_STREAMIO); } read_loop(fd, line, msg_bytes); successful_send(IVAL(line, 0)); break; case MSG_INFO: case MSG_ERROR: if (msg_bytes >= sizeof line) { overflow: rprintf(FERROR, "multiplexing overflow %d:%ld [%s]\n", tag, (long)msg_bytes, who_am_i()); exit_cleanup(RERR_STREAMIO); } read_loop(fd, line, msg_bytes); rwrite((enum logcode)tag, line, msg_bytes); break; default: rprintf(FERROR, "unexpected tag %d [%s]\n", tag, who_am_i()); exit_cleanup(RERR_STREAMIO); } } if (remaining == 0) io_flush(NORMAL_FLUSH); return cnt; } /** * 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 cnt; size_t total = 0; while (total < N) { cnt = readfd_unbuffered(fd, buffer + total, N-total); total += cnt; } if (fd == write_batch_monitor_in) { if ((size_t)write(batch_fd, buffer, total) != total) exit_cleanup(RERR_FILEIO); } if (fd == sock_f_in) stats.total_read += total; } unsigned short read_shortint(int f) { char b[2]; readfd(f, b, 2); return (UVAL(b, 1) << 8) + UVAL(b, 0); } int32 read_int(int f) { char b[4]; int32 num; readfd(f, b, 4); num = IVAL(b, 0); #if SIZEOF_INT32 > 4 if (num & (int32)0x80000000) num |= ~(int32)0xffffffff; #endif return num; } int64 read_longint(int f) { int64 num; char b[9]; if (protocol_version < 30) { num = read_int(f); if ((int32)num != (int32)0xffffffff) return num; #if SIZEOF_INT64 < 8 rprintf(FERROR, "Integer overflow: attempted 64-bit offset\n"); exit_cleanup(RERR_UNSUPPORTED); #else readfd(f, b, 8); num = IVAL(b,0) | (((int64)IVAL(b,4))<<32); #endif } else { int cnt; readfd(f, b, 3); cnt = int_byte_cnt[CVAL(b, 0)]; #if SIZEOF_INT64 < 8 if (cnt > 5 || (cnt == 5 && (CVAL(b,0)&0x3F || CVAL(b,1)&0x80))) { rprintf(FERROR, "Integer overflow: attempted 64-bit offset\n"); exit_cleanup(RERR_UNSUPPORTED); } #endif if (cnt > 3) readfd(f, b + 3, cnt - 3); switch (cnt) { case 3: num = NVAL3(b, 0); break; case 4: num = NVAL4(b, 0x80); break; case 5: num = NVAL5(b, 0xC0); break; #if SIZEOF_INT64 >= 8 case 6: num = NVAL6(b, 0xE0); break; case 7: num = NVAL7(b, 0xF0); break; case 8: num = NVAL8(b, 0xF8); break; case 9: num = NVAL8(b+1, 0); break; #endif default: exit_cleanup(RERR_PROTOCOL); /* impossible... */ } } return num; } void read_buf(int f, char *buf, size_t len) { readfd(f,buf,len); } void read_sbuf(int f, char *buf, size_t len) { readfd(f, buf, len); buf[len] = '\0'; } uchar read_byte(int f) { uchar c; readfd(f, (char *)&c, 1); return c; } int read_vstring(int f, char *buf, int bufsize) { int len = read_byte(f); if (len & 0x80) len = (len & ~0x80) * 0x100 + read_byte(f); if (len >= bufsize) { rprintf(FERROR, "over-long vstring received (%d > %d)\n", len, bufsize - 1); return -1; } if (len) readfd(f, buf, len); buf[len] = '\0'; return len; } /* Populate a sum_struct with values from the socket. This is * called by both the sender and the receiver. */ void read_sum_head(int f, struct sum_struct *sum) { sum->count = read_int(f); if (sum->count < 0) { rprintf(FERROR, "Invalid checksum count %ld [%s]\n", (long)sum->count, who_am_i()); exit_cleanup(RERR_PROTOCOL); } sum->blength = read_int(f); if (sum->blength < 0 || sum->blength > MAX_BLOCK_SIZE) { rprintf(FERROR, "Invalid block length %ld [%s]\n", (long)sum->blength, who_am_i()); exit_cleanup(RERR_PROTOCOL); } sum->s2length = protocol_version < 27 ? csum_length : (int)read_int(f); if (sum->s2length < 0 || sum->s2length > MD4_SUM_LENGTH) { rprintf(FERROR, "Invalid checksum length %d [%s]\n", sum->s2length, who_am_i()); exit_cleanup(RERR_PROTOCOL); } sum->remainder = read_int(f); if (sum->remainder < 0 || sum->remainder > sum->blength) { rprintf(FERROR, "Invalid remainder length %ld [%s]\n", (long)sum->remainder, who_am_i()); exit_cleanup(RERR_PROTOCOL); } } /* Send the values from a sum_struct over the socket. Set sum to * NULL if there are no checksums to send. This is called by both * the generator and the sender. */ void write_sum_head(int f, struct sum_struct *sum) { static struct sum_struct null_sum; if (sum == NULL) sum = &null_sum; write_int(f, sum->count); write_int(f, sum->blength); if (protocol_version >= 27) write_int(f, sum->s2length); write_int(f, sum->remainder); } /** * 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_writemax) 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 fd, looping as necessary to get * the job done and also (in certain circumstances) reading any data on * msg_fd_in to avoid deadlock. * * This function underlies the multiplexing system. The body of the * application never calls this function directly. */ static void writefd_unbuffered(int fd, const char *buf, size_t len) { size_t n, total = 0; fd_set w_fds, r_fds, e_fds; int maxfd, count, cnt, using_r_fds; int defer_save = defer_forwarding_messages; struct timeval tv; no_flush++; while (total < len) { FD_ZERO(&w_fds); FD_SET(fd, &w_fds); FD_ZERO(&e_fds); FD_SET(fd, &e_fds); maxfd = 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; using_r_fds = 1; } else using_r_fds = 0; tv.tv_sec = select_timeout; tv.tv_usec = 0; errno = 0; count = select(maxfd + 1, using_r_fds ? &r_fds : NULL, &w_fds, &e_fds, &tv); if (count <= 0) { if (count < 0 && errno == EBADF) exit_cleanup(RERR_SOCKETIO); check_timeout(); continue; } if (FD_ISSET(fd, &e_fds)) { rsyserr(FINFO, errno, "select exception on fd %d", fd); } if (using_r_fds && FD_ISSET(msg_fd_in, &r_fds)) read_msg_fd(); if (!FD_ISSET(fd, &w_fds)) continue; n = len - total; if (bwlimit_writemax && n > bwlimit_writemax) n = bwlimit_writemax; cnt = write(fd, buf + total, n); if (cnt <= 0) { if (cnt < 0) { if (errno == EINTR) continue; if (errno == EWOULDBLOCK || errno == EAGAIN) { msleep(1); continue; } } /* Don't try to write errors back across the stream. */ if (fd == sock_f_out) close_multiplexing_out(); rsyserr(FERROR, errno, "writefd_unbuffered failed to write %ld bytes [%s]", (long)len, who_am_i()); /* If the other side is sending us error messages, try * to grab any messages they sent before they died. */ while (fd == sock_f_out && io_multiplexing_in) { set_io_timeout(30); ignore_timeout = 0; readfd_unbuffered(sock_f_in, io_filesfrom_buf, sizeof io_filesfrom_buf); } exit_cleanup(RERR_STREAMIO); } total += cnt; defer_forwarding_messages = 1; if (fd == sock_f_out) { if (io_timeout || am_generator) last_io_out = time(NULL); sleep_for_bwlimit(cnt); } } defer_forwarding_messages = defer_save; no_flush--; } static void msg2sndr_flush(void) { if (defer_forwarding_messages) return; while (msg2sndr.head && io_multiplexing_out) { struct msg_list_item *m = msg2sndr.head; if (!(msg2sndr.head = m->next)) msg2sndr.tail = NULL; stats.total_written += m->len; defer_forwarding_messages = 1; writefd_unbuffered(sock_f_out, m->buf, m->len); defer_forwarding_messages = 0; free(m); } } /** * Write an message to a multiplexed stream. If this fails then rsync * exits. **/ static void mplex_write(enum msgcode code, const char *buf, size_t len) { char buffer[1024]; size_t n = len; SIVAL(buffer, 0, ((MPLEX_BASE + (int)code)<<24) + len); if (n > sizeof buffer - 4) n = 0; else memcpy(buffer + 4, buf, n); writefd_unbuffered(sock_f_out, buffer, n+4); len -= n; buf += n; if (len) { defer_forwarding_messages = 1; writefd_unbuffered(sock_f_out, buf, len); defer_forwarding_messages = 0; msg2sndr_flush(); } } void io_flush(int flush_it_all) { msg2genr_flush(flush_it_all); msg2sndr_flush(); if (!iobuf_out_cnt || no_flush) return; if (io_multiplexing_out) mplex_write(MSG_DATA, iobuf_out, iobuf_out_cnt); else writefd_unbuffered(sock_f_out, iobuf_out, iobuf_out_cnt); iobuf_out_cnt = 0; } static void writefd(int fd, const char *buf, size_t len) { if (fd == msg_fd_out) { rprintf(FERROR, "Internal error: wrong write used in receiver.\n"); exit_cleanup(RERR_PROTOCOL); } if (fd == sock_f_out) stats.total_written += len; if (fd == write_batch_monitor_out) { if ((size_t)write(batch_fd, buf, len) != len) exit_cleanup(RERR_FILEIO); } if (!iobuf_out || fd != sock_f_out) { writefd_unbuffered(fd, buf, len); return; } while (len) { int n = MIN((int)len, IO_BUFFER_SIZE - iobuf_out_cnt); if (n > 0) { memcpy(iobuf_out+iobuf_out_cnt, buf, n); buf += n; len -= n; iobuf_out_cnt += n; } if (iobuf_out_cnt == IO_BUFFER_SIZE) io_flush(NORMAL_FLUSH); } } void write_shortint(int f, unsigned short x) { char b[2]; b[0] = (char)x; b[1] = (char)(x >> 8); writefd(f, b, 2); } void write_int(int f, int32 x) { char b[4]; SIVAL(b, 0, x); writefd(f, b, 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) { char b[12]; #if SIZEOF_INT64 < 8 if (x < 0 || x > 0x7FFFFFFF) { rprintf(FERROR, "Integer overflow: attempted 64-bit offset\n"); exit_cleanup(RERR_UNSUPPORTED); } #endif if (protocol_version < 30) { char * const s = b+4; SIVAL(s, 0, x); #if SIZEOF_INT64 < 8 writefd(f, s, 4); #else if (x <= 0x7FFFFFFF && x >= 0) { writefd(f, s, 4); return; } memset(b, 0xFF, 4); SIVAL(s, 4, x >> 32); writefd(f, b, 12); } else if (x < 0) { goto all_bits; #endif } else if (x < ((int32)1<<(3*8-1))) { b[0] = (char)(x >> 16); b[1] = (char)(x >> 8); b[2] = (char)x; writefd(f, b, 3); } else if (x < ((int64)1<<(4*8-2))) { b[0] = (char)((x >> 24) | 0x80); b[1] = (char)(x >> 16); b[2] = (char)(x >> 8); b[3] = (char)x; writefd(f, b, 4); #if SIZEOF_INT64 < 8 } else { b[0] = 0xC0; b[1] = (char)(x >> 24); b[2] = (char)(x >> 16); b[3] = (char)(x >> 8); b[4] = (char)x; writefd(f, b, 5); } #else } else if (x < ((int64)1<<(5*8-3))) { b[0] = (char)((x >> 32) | 0xC0); b[1] = (char)(x >> 24); b[2] = (char)(x >> 16); b[3] = (char)(x >> 8); b[4] = (char)x; writefd(f, b, 5); } else if (x < ((int64)1<<(6*8-4))) { b[0] = (char)((x >> 40) | 0xE0); b[1] = (char)(x >> 32); b[2] = (char)(x >> 24); b[3] = (char)(x >> 16); b[4] = (char)(x >> 8); b[5] = (char)x; writefd(f, b, 6); } else if (x < ((int64)1<<(7*8-5))) { b[0] = (char)((x >> 48) | 0xF0); b[1] = (char)(x >> 40); b[2] = (char)(x >> 32); b[3] = (char)(x >> 24); b[4] = (char)(x >> 16); b[5] = (char)(x >> 8); b[6] = (char)x; writefd(f, b, 7); } else if (x < ((int64)1<<(8*8-6))) { b[0] = (char)((x >> 56) | 0xF8); b[1] = (char)(x >> 48); b[2] = (char)(x >> 40); b[3] = (char)(x >> 32); b[4] = (char)(x >> 24); b[5] = (char)(x >> 16); b[6] = (char)(x >> 8); b[7] = (char)x; writefd(f, b, 8); } else { all_bits: b[0] = (char)0xFC; b[1] = (char)(x >> 56); b[2] = (char)(x >> 48); b[3] = (char)(x >> 40); b[4] = (char)(x >> 32); b[5] = (char)(x >> 24); b[6] = (char)(x >> 16); b[7] = (char)(x >> 8); b[8] = (char)x; writefd(f, b, 9); } #endif } void write_buf(int f, const char *buf, size_t len) { writefd(f,buf,len); } /** Write a string to the connection */ void write_sbuf(int f, const char *buf) { writefd(f, buf, strlen(buf)); } void write_byte(int f, uchar c) { writefd(f, (char *)&c, 1); } void write_vstring(int f, const char *str, int len) { uchar lenbuf[3], *lb = lenbuf; if (len > 0x7F) { if (len > 0x7FFF) { rprintf(FERROR, "attempting to send over-long vstring (%d > %d)\n", len, 0x7FFF); exit_cleanup(RERR_PROTOCOL); } *lb++ = len / 0x100 + 0x80; } *lb = len; writefd(f, (char*)lenbuf, lb - lenbuf + 1); if (len) writefd(f, str, len); } /** * 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') break; if (buf[0] != '\r') { buf++; maxlen--; } } *buf = '\0'; return maxlen > 0; } void io_printf(int fd, const char *format, ...) { va_list ap; char buf[BIGPATHBUFLEN]; int len; va_start(ap, format); len = vsnprintf(buf, sizeof buf, format, ap); va_end(ap); if (len < 0) exit_cleanup(RERR_STREAMIO); if (len > (int)sizeof buf) { rprintf(FERROR, "io_printf() was too long for the buffer.\n"); exit_cleanup(RERR_STREAMIO); } write_sbuf(fd, buf); } /** Setup for multiplexing a MSG_* stream with the data stream. */ void io_start_multiplex_out(void) { io_flush(NORMAL_FLUSH); io_start_buffering_out(); io_multiplexing_out = 1; } /** Setup for multiplexing a MSG_* stream with the data stream. */ void io_start_multiplex_in(void) { io_flush(NORMAL_FLUSH); io_start_buffering_in(); io_multiplexing_in = 1; } /** Write an message to the multiplexed data stream. */ int io_multiplex_write(enum msgcode code, const char *buf, size_t len) { if (!io_multiplexing_out) return 0; io_flush(NORMAL_FLUSH); stats.total_written += (len+4); mplex_write(code, buf, len); return 1; } void close_multiplexing_in(void) { io_multiplexing_in = 0; } /** Stop output multiplexing. */ void close_multiplexing_out(void) { io_multiplexing_out = 0; } void start_write_batch(int fd) { write_stream_flags(batch_fd); /* 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); 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; }