Mention atimes & protected-args in capabilities.

[rsync.git] / log.c

/*
 * Logging and utility functions.
 *
 * Copyright (C) 1998-2001 Andrew Tridgell <tridge@samba.org>
 * Copyright (C) 2000-2001 Martin Pool <mbp@samba.org>
 * Copyright (C) 2003-2020 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 3 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, visit the http://fsf.org website.
 */

#include "rsync.h"
#include "itypes.h"
#include "inums.h"

extern int dry_run;
extern int am_daemon;
extern int am_server;
extern int am_sender;
extern int am_generator;
extern int local_server;
extern int quiet;
extern int module_id;
extern int allow_8bit_chars;
extern int protocol_version;
extern int always_checksum;
extern int preserve_times;
extern int msgs2stderr;
extern int xfersum_type;
extern int checksum_type;
extern int stdout_format_has_i;
extern int stdout_format_has_o_or_i;
extern int logfile_format_has_i;
extern int logfile_format_has_o_or_i;
extern int receiver_symlink_times;
extern int64 total_data_written;
extern int64 total_data_read;
extern mode_t orig_umask;
extern char *auth_user;
extern char *stdout_format;
extern char *logfile_format;
extern char *logfile_name;
#ifdef ICONV_CONST
extern iconv_t ic_chck;
#endif
#ifdef ICONV_OPTION
extern iconv_t ic_recv;
#endif
extern char curr_dir[MAXPATHLEN];
extern char *full_module_path;
extern unsigned int module_dirlen;
extern char sender_file_sum[MAX_DIGEST_LEN];
extern const char undetermined_hostname[];

static int log_initialised;
static int logfile_was_closed;
static FILE *logfile_fp;
struct stats stats;

int got_xfer_error = 0;
int output_needs_newline = 0;
int send_msgs_to_gen = 0;

static int64 initial_data_written;
static int64 initial_data_read;

struct {
        int code;
        char const *name;
} const rerr_names[] = {
        { RERR_SYNTAX     , "syntax or usage error" },
        { RERR_PROTOCOL   , "protocol incompatibility" },
        { RERR_FILESELECT , "errors selecting input/output files, dirs" },
        { RERR_UNSUPPORTED, "requested action not supported" },
        { RERR_STARTCLIENT, "error starting client-server protocol" },
        { RERR_SOCKETIO   , "error in socket IO" },
        { RERR_FILEIO     , "error in file IO" },
        { RERR_STREAMIO   , "error in rsync protocol data stream" },
        { RERR_MESSAGEIO  , "errors with program diagnostics" },
        { RERR_IPC        , "error in IPC code" },
        { RERR_CRASHED    , "sibling process crashed" },
        { RERR_TERMINATED , "sibling process terminated abnormally" },
        { RERR_SIGNAL1    , "received SIGUSR1" },
        { RERR_SIGNAL     , "received SIGINT, SIGTERM, or SIGHUP" },
        { RERR_WAITCHILD  , "waitpid() failed" },
        { RERR_MALLOC     , "error allocating core memory buffers" },
        { RERR_PARTIAL    , "some files/attrs were not transferred (see previous errors)" },
        { RERR_VANISHED   , "some files vanished before they could be transferred" },
        { RERR_DEL_LIMIT  , "the --max-delete limit stopped deletions" },
        { RERR_TIMEOUT    , "timeout in data send/receive" },
        { RERR_CONTIMEOUT , "timeout waiting for daemon connection" },
        { RERR_CMD_FAILED , "remote shell failed" },
        { RERR_CMD_KILLED , "remote shell killed" },
        { RERR_CMD_RUN    , "remote command could not be run" },
        { RERR_CMD_NOTFOUND,"remote command not found" },
        { 0, NULL }
};

/*
 * Map from rsync error code to name, or return NULL.
 */
static char const *rerr_name(int code)
{
        int i;
        for (i = 0; rerr_names[i].name; i++) {
                if (rerr_names[i].code == code)
                        return rerr_names[i].name;
        }
        return NULL;
}

static void logit(int priority, const char *buf)
{
        if (logfile_was_closed)
                logfile_reopen();
        if (logfile_fp) {
                fprintf(logfile_fp, "%s [%d] %s", timestring(time(NULL)), (int)getpid(), buf);
                fflush(logfile_fp);
        } else {
                syslog(priority, "%s", buf);
        }
}

static void syslog_init()
{
        int options = LOG_PID;

#ifdef LOG_NDELAY
        options |= LOG_NDELAY;
#endif

#ifdef LOG_DAEMON
        openlog(lp_syslog_tag(module_id), options, lp_syslog_facility(module_id));
#else
        openlog(lp_syslog_tag(module_id), options);
#endif

#ifndef LOG_NDELAY
        logit(LOG_INFO, "rsyncd started\n");
#endif
}

static void logfile_open(void)
{
        mode_t old_umask = umask(022 | orig_umask);
        logfile_fp = fopen(logfile_name, "a");
        umask(old_umask);
        if (!logfile_fp) {
                int fopen_errno = errno;
                /* Rsync falls back to using syslog on failure. */
                syslog_init();
                rsyserr(FERROR, fopen_errno,
                        "failed to open log-file %s", logfile_name);
                rprintf(FINFO, "Ignoring \"log file\" setting.\n");
                logfile_name = "";
        }
}

void log_init(int restart)
{
        if (log_initialised) {
                if (!restart) /* Note: a restart only happens with am_daemon */
                        return;
                assert(logfile_name); /* all am_daemon procs got at least an empty string */
                if (strcmp(logfile_name, lp_log_file(module_id)) != 0) {
                        if (logfile_fp) {
                                fclose(logfile_fp);
                                logfile_fp = NULL;
                        } else
                                closelog();
                        logfile_name = NULL;
                } else if (*logfile_name)
                        return; /* unchanged, non-empty "log file" names */
                else if (lp_syslog_facility(-1) != lp_syslog_facility(module_id)
                      || strcmp(lp_syslog_tag(-1), lp_syslog_tag(module_id)) != 0)
                        closelog();
                else
                        return; /* unchanged syslog settings */
        } else
                log_initialised = 1;

        /* This looks pointless, but it is needed in order for the
         * C library on some systems to fetch the timezone info
         * before the chroot. */
        timestring(time(NULL));

        /* Optionally use a log file instead of syslog.  (Non-daemon
         * rsyncs will have already set logfile_name, as needed.) */
        if (am_daemon && !logfile_name)
                logfile_name = lp_log_file(module_id);
        if (logfile_name && *logfile_name)
                logfile_open();
        else
                syslog_init();
}

/* Note that this close & reopen idiom intentionally ignores syslog logging. */
void logfile_close(void)
{
        if (logfile_fp) {
                logfile_was_closed = 1;
                fclose(logfile_fp);
                logfile_fp = NULL;
        }
}

void logfile_reopen(void)
{
        if (logfile_was_closed) {
                logfile_was_closed = 0;
                logfile_open();
        }
}

static void filtered_fwrite(FILE *f, const char *in_buf, int in_len, int use_isprint, char end_char)
{
        char outbuf[1024], *ob = outbuf;
        const char *end = in_buf + in_len;
        while (in_buf < end) {
                if (ob - outbuf >= (int)sizeof outbuf - 10) {
                        if (fwrite(outbuf, ob - outbuf, 1, f) != 1)
                                exit_cleanup(RERR_MESSAGEIO);
                        ob = outbuf;
                }
                if ((in_buf < end - 4 && *in_buf == '\\' && in_buf[1] == '#'
                  && isDigit(in_buf + 2) && isDigit(in_buf + 3) && isDigit(in_buf + 4))
                 || (*in_buf != '\t' && ((use_isprint && !isPrint(in_buf)) || *(uchar*)in_buf < ' ')))
                        ob += snprintf(ob, 6, "\\#%03o", *(uchar*)in_buf++);
                else
                        *ob++ = *in_buf++;
        }
        if (end_char) /* The "- 10" above means that there is always room for one more char here. */
                *ob++ = end_char;
        if (ob != outbuf && fwrite(outbuf, ob - outbuf, 1, f) != 1)
                exit_cleanup(RERR_MESSAGEIO);
}

/* this is the underlying (unformatted) rsync debugging function. Call
 * it with FINFO, FERROR_*, FWARNING, FLOG, or FCLIENT.  Note: recursion
 * can happen with certain fatal conditions. */
void rwrite(enum logcode code, const char *buf, int len, int is_utf8)
{
        char trailing_CR_or_NL;
        FILE *f = msgs2stderr ? stderr : stdout;
#ifdef ICONV_OPTION
        iconv_t ic = is_utf8 && ic_recv != (iconv_t)-1 ? ic_recv : ic_chck;
#else
#ifdef ICONV_CONST
        iconv_t ic = ic_chck;
#endif
#endif

        if (len < 0)
                exit_cleanup(RERR_MESSAGEIO);

        if (msgs2stderr) {
                /* A normal daemon can get msgs2stderr set if the socket is busted, so we
                 * change the message destination into an FLOG message in order to try to
                 * get some info about an abnormal-exit into the log file. An rsh daemon
                 * can have this set via user request, so we'll leave the code alone so
                 * that the msg gets logged and then sent to stderr after that. */
                if (am_daemon > 0 && code != FCLIENT)
                        code = FLOG;
        } else if (send_msgs_to_gen) {
                assert(!is_utf8);
                /* Pass the message to our sibling in native charset. */
                send_msg((enum msgcode)code, buf, len, 0);
                return;
        }

        if (code == FERROR_SOCKET) /* This gets simplified for a non-sibling. */
                code = FERROR;
        else if (code == FERROR_UTF8) {
                is_utf8 = 1;
                code = FERROR;
        }

        if (code == FCLIENT)
                code = FINFO;
        else if (am_daemon || logfile_name) {
                static int in_block;
                char msg[2048];
                int priority = code == FINFO || code == FLOG ? LOG_INFO :  LOG_WARNING;

                if (in_block)
                        return;
                in_block = 1;
                if (!log_initialised)
                        log_init(0);
                strlcpy(msg, buf, MIN((int)sizeof msg, len + 1));
                logit(priority, msg);
                in_block = 0;

                if (code == FLOG || (am_daemon && !am_server))
                        return;
        } else if (code == FLOG)
                return;

        switch (code) {
        case FERROR_XFER:
                got_xfer_error = 1;
                /* FALL THROUGH */
        case FERROR:
        case FWARNING:
                f = stderr;
                break;
        case FINFO:
                if (quiet)
                        return;
                break;
        /*case FLOG:*/
        /*case FCLIENT:*/
        /*case FERROR_UTF8:*/
        /*case FERROR_SOCKET:*/
        default:
                fprintf(stderr, "Bad logcode in rwrite(): %d [%s]\n", (int)code, who_am_i());
                exit_cleanup(RERR_MESSAGEIO);
        }

        if (am_server && !msgs2stderr) {
                enum msgcode msg = (enum msgcode)code;
                if (protocol_version < 30) {
                        if (msg == MSG_ERROR)
                                msg = MSG_ERROR_XFER;
                        else if (msg == MSG_WARNING)
                                msg = MSG_INFO;
                }
                /* Pass the message to the non-server side. */
                if (send_msg(msg, buf, len, !is_utf8))
                        return;
                if (am_daemon > 0) {
                        /* TODO: can we send the error to the user somehow? */
                        return;
                }
                f = stderr;
        }

        if (output_needs_newline) {
                fputc('\n', f);
                output_needs_newline = 0;
        }

        trailing_CR_or_NL = len && (buf[len-1] == '\n' || buf[len-1] == '\r')
                          ? buf[--len] : 0;

        if (len && buf[0] == '\r') {
                fputc('\r', f);
                buf++;
                len--;
        }

#ifdef ICONV_CONST
        if (ic != (iconv_t)-1) {
                xbuf outbuf, inbuf;
                char convbuf[1024];
                int ierrno;

                INIT_CONST_XBUF(outbuf, convbuf);
                INIT_XBUF(inbuf, (char*)buf, len, (size_t)-1);

                while (inbuf.len) {
                        iconvbufs(ic, &inbuf, &outbuf, inbuf.pos ? 0 : ICB_INIT);
                        ierrno = errno;
                        if (outbuf.len) {
                                filtered_fwrite(f, convbuf, outbuf.len, 0, 0);
                                outbuf.len = 0;
                        }
                        /* Log one byte of illegal/incomplete sequence and continue with
                         * the next character. Check that the buffer is non-empty for the
                         * sake of robustness. */
                        if ((ierrno == EILSEQ || ierrno == EINVAL) && inbuf.len) {
                                fprintf(f, "\\#%03o", CVAL(inbuf.buf, inbuf.pos++));
                                inbuf.len--;
                        }
                }

                if (trailing_CR_or_NL) {
                        fputc(trailing_CR_or_NL, f);
                        fflush(f);
                }
        } else
#endif
        {
                filtered_fwrite(f, buf, len, !allow_8bit_chars, trailing_CR_or_NL);
                if (trailing_CR_or_NL)
                        fflush(f);
        }
}

/* This is the rsync debugging function. Call it with FINFO, FERROR_*,
 * FWARNING, FLOG, or FCLIENT. */
void rprintf(enum logcode code, const char *format, ...)
{
        va_list ap;
        char buf[BIGPATHBUFLEN];
        size_t len;

        va_start(ap, format);
        len = vsnprintf(buf, sizeof buf, format, ap);
        va_end(ap);

        /* Deal with buffer overruns.  Instead of panicking, just
         * truncate the resulting string.  (Note that configure ensures
         * that we have a vsnprintf() that doesn't ever return -1.) */
        if (len > sizeof buf - 1) {
                static const char ellipsis[] = "[...]";

                /* Reset length, and zero-terminate the end of our buffer */
                len = sizeof buf - 1;
                buf[len] = '\0';

                /* Copy the ellipsis to the end of the string, but give
                 * us one extra character:
                 *
                 *                  v--- null byte at buf[sizeof buf - 1]
                 *        abcdefghij0
                 *     -> abcd[...]00  <-- now two null bytes at end
                 *
                 * If the input format string has a trailing newline,
                 * we copy it into that extra null; if it doesn't, well,
                 * all we lose is one byte.  */
                memcpy(buf+len-sizeof ellipsis, ellipsis, sizeof ellipsis);
                if (format[strlen(format)-1] == '\n') {
                        buf[len-1] = '\n';
                }
        }

        rwrite(code, buf, len, 0);
}

/* This is like rprintf, but it also tries to print some
 * representation of the error code.  Normally errcode = errno.
 *
 * Unlike rprintf, this always adds a newline and there should not be
 * one in the format string.
 *
 * Note that since strerror might involve dynamically loading a
 * message catalog we need to call it once before chroot-ing. */
void rsyserr(enum logcode code, int errcode, const char *format, ...)
{
        va_list ap;
        char buf[BIGPATHBUFLEN];
        size_t len;

        len = snprintf(buf, sizeof buf, RSYNC_NAME ": [%s] ", who_am_i());

        va_start(ap, format);
        len += vsnprintf(buf + len, sizeof buf - len, format, ap);
        va_end(ap);

        if (len < sizeof buf) {
                len += snprintf(buf + len, sizeof buf - len,
                                ": %s (%d)\n", strerror(errcode), errcode);
        }
        if (len >= sizeof buf)
                exit_cleanup(RERR_MESSAGEIO);

        rwrite(code, buf, len, 0);
}

void rflush(enum logcode code)
{
        FILE *f;

        if (am_daemon || code == FLOG)
                return;

        if (!am_server && (code == FINFO || code == FCLIENT))
                f = stdout;
        else
                f = stderr;

        fflush(f);
}

void remember_initial_stats(void)
{
        initial_data_read = total_data_read;
        initial_data_written = total_data_written;
}

/* A generic logging routine for send/recv, with parameter substitiution. */
static void log_formatted(enum logcode code, const char *format, const char *op,
                          struct file_struct *file, const char *fname, int iflags,
                          const char *hlink)
{
        char buf[MAXPATHLEN+1024], buf2[MAXPATHLEN], fmt[32];
        char *p, *s, *c;
        const char *n;
        size_t len, total;
        int64 b;

        *fmt = '%';

        /* We expand % codes one by one in place in buf.  We don't
         * copy in the terminating null of the inserted strings, but
         * rather keep going until we reach the null of the format. */
        total = strlcpy(buf, format, sizeof buf);
        if (total > MAXPATHLEN) {
                rprintf(FERROR, "log-format string is WAY too long!\n");
                exit_cleanup(RERR_MESSAGEIO);
        }
        buf[total++] = '\n';
        buf[total] = '\0';

        for (p = buf; (p = strchr(p, '%')) != NULL; ) {
                int humanize = 0;
                s = p++;
                c = fmt + 1;
                while (*p == '\'') {
                        humanize++;
                        p++;
                }
                if (*p == '-')
                        *c++ = *p++;
                while (isDigit(p) && c - fmt < (int)(sizeof fmt) - 8)
                        *c++ = *p++;
                while (*p == '\'') {
                        humanize++;
                        p++;
                }
                if (!*p)
                        break;
                *c = '\0';
                n = NULL;

                /* Note for %h and %a: it doesn't matter what fd we pass to
                 * client_{name,addr} because rsync_module will already have
                 * forced the answer to be cached (assuming, of course, for %h
                 * that lp_reverse_lookup(module_id) is true). */
                switch (*p) {
                case 'h':
                        if (am_daemon) {
                                n = lp_reverse_lookup(module_id)
                                  ? client_name(0) : undetermined_hostname;
                        }
                        break;
                case 'a':
                        if (am_daemon)
                                n = client_addr(0);
                        break;
                case 'l':
                        strlcat(fmt, "s", sizeof fmt);
                        snprintf(buf2, sizeof buf2, fmt,
                                 do_big_num(F_LENGTH(file), humanize, NULL));
                        n = buf2;
                        break;
                case 'U':
                        strlcat(fmt, "u", sizeof fmt);
                        snprintf(buf2, sizeof buf2, fmt,
                                 uid_ndx ? F_OWNER(file) : 0);
                        n = buf2;
                        break;
                case 'G':
                        if (!gid_ndx || file->flags & FLAG_SKIP_GROUP)
                                n = "DEFAULT";
                        else {
                                strlcat(fmt, "u", sizeof fmt);
                                snprintf(buf2, sizeof buf2, fmt,
                                         F_GROUP(file));
                                n = buf2;
                        }
                        break;
                case 'p':
                        strlcat(fmt, "d", sizeof fmt);
                        snprintf(buf2, sizeof buf2, fmt, (int)getpid());
                        n = buf2;
                        break;
                case 'M':
                        n = c = timestring(file->modtime);
                        while ((c = strchr(c, ' ')) != NULL)
                                *c = '-';
                        break;
                case 'B':
                        c = buf2 + MAXPATHLEN - PERMSTRING_SIZE - 1;
                        permstring(c, file->mode);
                        n = c + 1; /* skip the type char */
                        break;
                case 'o':
                        n = op;
                        break;
                case 'f':
                        if (fname) {
                                c = f_name_buf();
                                strlcpy(c, fname, MAXPATHLEN);
                        } else
                                c = f_name(file, NULL);
                        if (am_sender && F_PATHNAME(file)) {
                                pathjoin(buf2, sizeof buf2,
                                         F_PATHNAME(file), c);
                                clean_fname(buf2, 0);
                                if (fmt[1]) {
                                        strlcpy(c, buf2, MAXPATHLEN);
                                        n = c;
                                } else
                                        n = buf2;
                        } else if (am_daemon && *c != '/') {
                                pathjoin(buf2, sizeof buf2,
                                         curr_dir + module_dirlen, c);
                                clean_fname(buf2, 0);
                                if (fmt[1]) {
                                        strlcpy(c, buf2, MAXPATHLEN);
                                        n = c;
                                } else
                                        n = buf2;
                        } else {
                                clean_fname(c, 0);
                                n = c;
                        }
                        if (*n == '/')
                                n++;
                        break;
                case 'n':
                        if (fname) {
                                c = f_name_buf();
                                strlcpy(c, fname, MAXPATHLEN);
                        } else
                                c = f_name(file, NULL);
                        if (S_ISDIR(file->mode))
                                strlcat(c, "/", MAXPATHLEN);
                        n = c;
                        break;
                case 'L':
                        if (hlink && *hlink) {
                                n = hlink;
                                strlcpy(buf2, " => ", sizeof buf2);
                        } else if (S_ISLNK(file->mode) && !fname) {
                                n = F_SYMLINK(file);
                                strlcpy(buf2, " -> ", sizeof buf2);
                        } else {
                                n = "";
                                if (!fmt[1])
                                        break;
                                strlcpy(buf2, "    ", sizeof buf2);
                        }
                        strlcat(fmt, "s", sizeof fmt);
                        snprintf(buf2 + 4, sizeof buf2 - 4, fmt, n);
                        n = buf2;
                        break;
                case 'm':
                        n = lp_name(module_id);
                        break;
                case 't':
                        n = timestring(time(NULL));
                        break;
                case 'P':
                        n = full_module_path;
                        break;
                case 'u':
                        n = auth_user;
                        break;
                case 'b':
                case 'c':
                        if (!(iflags & ITEM_TRANSFER))
                                b = 0;
                        else if ((!!am_sender) ^ (*p == 'c'))
                                b = total_data_written - initial_data_written;
                        else
                                b = total_data_read - initial_data_read;
                        strlcat(fmt, "s", sizeof fmt);
                        snprintf(buf2, sizeof buf2, fmt,
                                 do_big_num(b, humanize, NULL));
                        n = buf2;
                        break;
                case 'C':
                        n = NULL;
                        if (S_ISREG(file->mode)) {
                                if (always_checksum)
                                        n = sum_as_hex(checksum_type, F_SUM(file), 1);
                                else if (iflags & ITEM_TRANSFER)
                                        n = sum_as_hex(xfersum_type, sender_file_sum, 0);
                        }
                        if (!n) {
                                int sum_len = csum_len_for_type(always_checksum ? checksum_type : xfersum_type,
                                                                always_checksum);
                                memset(buf2, ' ', sum_len*2);
                                buf2[sum_len*2] = '\0';
                                n = buf2;
                        }
                        break;
                case 'i':
                        if (iflags & ITEM_DELETED) {
                                n = "*deleting  ";
                                break;
                        }
                        n  = c = buf2 + MAXPATHLEN - 32;
                        c[0] = iflags & ITEM_LOCAL_CHANGE
                             ? iflags & ITEM_XNAME_FOLLOWS ? 'h' : 'c'
                             : !(iflags & ITEM_TRANSFER) ? '.'
                             : !local_server && *op == 's' ? '<' : '>';
                        if (S_ISLNK(file->mode)) {
                                c[1] = 'L';
                                c[3] = '.';
                                c[4] = !(iflags & ITEM_REPORT_TIME) ? '.'
                                     : !preserve_times || !receiver_symlink_times
                                    || (iflags & ITEM_REPORT_TIMEFAIL) ? 'T' : 't';
                        } else {
                                c[1] = S_ISDIR(file->mode) ? 'd'
                                     : IS_SPECIAL(file->mode) ? 'S'
                                     : IS_DEVICE(file->mode) ? 'D' : 'f';
                                c[3] = !(iflags & ITEM_REPORT_SIZE) ? '.' : 's';
                                c[4] = !(iflags & ITEM_REPORT_TIME) ? '.'
                                     : !preserve_times ? 'T' : 't';
                        }
                        c[2] = !(iflags & ITEM_REPORT_CHANGE) ? '.' : 'c';
                        c[5] = !(iflags & ITEM_REPORT_PERMS) ? '.' : 'p';
                        c[6] = !(iflags & ITEM_REPORT_OWNER) ? '.' : 'o';
                        c[7] = !(iflags & ITEM_REPORT_GROUP) ? '.' : 'g';
                        c[8] = !(iflags & ITEM_REPORT_ATIME) ? '.'
                             : S_ISLNK(file->mode) ? 'U' : 'u';
                        c[9] = !(iflags & ITEM_REPORT_ACL) ? '.' : 'a';
                        c[10] = !(iflags & ITEM_REPORT_XATTR) ? '.' : 'x';
                        c[11] = '\0';

                        if (iflags & (ITEM_IS_NEW|ITEM_MISSING_DATA)) {
                                char ch = iflags & ITEM_IS_NEW ? '+' : '?';
                                int i;
                                for (i = 2; c[i]; i++)
                                        c[i] = ch;
                        } else if (c[0] == '.' || c[0] == 'h' || c[0] == 'c') {
                                int i;
                                for (i = 2; c[i]; i++) {
                                        if (c[i] != '.')
                                                break;
                                }
                                if (!c[i]) {
                                        for (i = 2; c[i]; i++)
                                                c[i] = ' ';
                                }
                        }
                        break;
                }

                /* "n" is the string to be inserted in place of this % code. */
                if (!n)
                        continue;
                if (n != buf2 && fmt[1]) {
                        strlcat(fmt, "s", sizeof fmt);
                        snprintf(buf2, sizeof buf2, fmt, n);
                        n = buf2;
                }
                len = strlen(n);

                /* Subtract the length of the escape from the string's size. */
                total -= p - s + 1;

                if (len + total >= (size_t)sizeof buf) {
                        rprintf(FERROR,
                                "buffer overflow expanding %%%c -- exiting\n",
                                p[0]);
                        exit_cleanup(RERR_MESSAGEIO);
                }

                /* Shuffle the rest of the string along to make space for n */
                if (len != (size_t)(p - s + 1))
                        memmove(s + len, p + 1, total - (s - buf) + 1);
                total += len;

                /* Insert the contents of string "n", but NOT its null. */
                if (len)
                        memcpy(s, n, len);

                /* Skip over inserted string; continue looking */
                p = s + len;
        }

        rwrite(code, buf, total, 0);
}

/* Return 1 if the format escape is in the log-format string (e.g. look for
 * the 'b' in the "%9b" format escape). */
int log_format_has(const char *format, char esc)
{
        const char *p;

        if (!format)
                return 0;

        for (p = format; (p = strchr(p, '%')) != NULL; ) {
                for (p++; *p == '\''; p++) {} /*SHARED ITERATOR*/
                if (*p == '-')
                        p++;
                while (isDigit(p))
                        p++;
                while (*p == '\'') p++;
                if (!*p)
                        break;
                if (*p == esc)
                        return 1;
        }
        return 0;
}

/* Log the transfer of a file.  If the code is FCLIENT, the output just goes
 * to stdout.  If it is FLOG, it just goes to the log file.  Otherwise we
 * output to both. */
void log_item(enum logcode code, struct file_struct *file, int iflags, const char *hlink)
{
        const char *s_or_r = am_sender ? "send" : "recv";

        if (code != FLOG && stdout_format && !am_server)
                log_formatted(FCLIENT, stdout_format, s_or_r, file, NULL, iflags, hlink);
        if (code != FCLIENT && logfile_format && *logfile_format)
                log_formatted(FLOG, logfile_format, s_or_r, file, NULL, iflags, hlink);
}

void maybe_log_item(struct file_struct *file, int iflags, int itemizing, const char *buf)
{
        int significant_flags = iflags & SIGNIFICANT_ITEM_FLAGS;
        int see_item = itemizing && (significant_flags || *buf
                || stdout_format_has_i > 1 || (INFO_GTE(NAME, 2) && stdout_format_has_i));
        int local_change = iflags & ITEM_LOCAL_CHANGE && significant_flags;
        if (am_server) {
                if (logfile_name && !dry_run && see_item
                 && (significant_flags || logfile_format_has_i))
                        log_item(FLOG, file, iflags, buf);
        } else if (see_item || local_change || *buf
            || (S_ISDIR(file->mode) && significant_flags)) {
                enum logcode code = significant_flags || logfile_format_has_i ? FINFO : FCLIENT;
                log_item(code, file, iflags, buf);
        }
}

void log_delete(const char *fname, int mode)
{
        static struct {
                union file_extras ex[4]; /* just in case... */
                struct file_struct file;
        } x; /* Zero-initialized due to static declaration. */
        int len = strlen(fname);
        const char *fmt;

        x.file.mode = mode;

        if (am_server && protocol_version >= 29 && len < MAXPATHLEN) {
                if (S_ISDIR(mode))
                        len++; /* directories include trailing null */
                send_msg(MSG_DELETED, fname, len, am_generator);
        } else if (!INFO_GTE(DEL, 1) && !stdout_format)
                ;
        else {
                fmt = stdout_format_has_o_or_i ? stdout_format : "deleting %n";
                log_formatted(FCLIENT, fmt, "del.", &x.file, fname, ITEM_DELETED, NULL);
        }

        if (!logfile_name || dry_run || !logfile_format)
                return;

        fmt = logfile_format_has_o_or_i ? logfile_format : "deleting %n";
        log_formatted(FLOG, fmt, "del.", &x.file, fname, ITEM_DELETED, NULL);
}

/*
 * Called when the transfer is interrupted for some reason.
 *
 * Code is one of the RERR_* codes from errcode.h, or terminating
 * successfully.
 */
void log_exit(int code, const char *file, int line)
{
        /* The receiving side's stats are split between 2 procs until the
         * end of the run, so only the sender can output non-final info. */
        if (code == 0 || am_sender) {
                rprintf(FLOG,"sent %s bytes  received %s bytes  total size %s\n",
                        big_num(stats.total_written),
                        big_num(stats.total_read),
                        big_num(stats.total_size));
        }
        if (code != 0 && am_server != 2) {
                const char *name;

                name = rerr_name(code);
                if (!name)
                        name = "unexplained error";

                /* VANISHED is not an error, only a warning */
                if (code == RERR_VANISHED) {
                        rprintf(FWARNING, "rsync warning: %s (code %d) at %s(%d) [%s=%s]\n",
                                name, code, file, line, who_am_i(), RSYNC_VERSION);
                } else {
                        rprintf(FERROR, "rsync error: %s (code %d) at %s(%d) [%s=%s]\n",
                                name, code, file, line, who_am_i(), RSYNC_VERSION);
                }
        }
}