/* $Cambridge: exim/src/src/log.c,v 1.15 2010/06/06 00:27:52 pdp Exp $ */ /************************************************* * Exim - an Internet mail transport agent * *************************************************/ /* Copyright (c) University of Cambridge 1995 - 2009 */ /* See the file NOTICE for conditions of use and distribution. */ /* Functions for writing log files. The code for maintaining datestamped log files was originally contributed by Tony Sheen. */ #include "exim.h" #define LOG_NAME_SIZE 256 #define MAX_SYSLOG_LEN 870 #define LOG_MODE_FILE 1 #define LOG_MODE_SYSLOG 2 enum { lt_main, lt_reject, lt_panic, lt_debug, lt_process }; static uschar *log_names[] = { US"main", US"reject", US"panic", US"debug", US"process" }; /************************************************* * Local static variables * *************************************************/ static uschar mainlog_name[LOG_NAME_SIZE]; static uschar rejectlog_name[LOG_NAME_SIZE]; static uschar debuglog_name[LOG_NAME_SIZE]; static uschar *mainlog_datestamp = NULL; static uschar *rejectlog_datestamp = NULL; static int mainlogfd = -1; static int rejectlogfd = -1; static ino_t mainlog_inode = 0; static ino_t rejectlog_inode = 0; static uschar *panic_save_buffer = NULL; static BOOL panic_recurseflag = FALSE; static BOOL syslog_open = FALSE; static BOOL path_inspected = FALSE; static int logging_mode = LOG_MODE_FILE; static uschar *file_path = US""; /************************************************* * Write to syslog * *************************************************/ /* The given string is split into sections according to length, or at embedded newlines, and syslogged as a numbered sequence if it is overlong or if there is more than one line. However, if we are running in the test harness, do not do anything. (The test harness doesn't use syslog - for obvious reasons - but we can get here if there is a failure to open the panic log.) Arguments: priority syslog priority s the string to be written Returns: nothing */ static void write_syslog(int priority, uschar *s) { int len, pass; int linecount = 0; if (running_in_test_harness) return; if (!syslog_timestamp) s += log_timezone? 26 : 20; len = Ustrlen(s); #ifndef NO_OPENLOG if (!syslog_open) { #ifdef SYSLOG_LOG_PID openlog(CS syslog_processname, LOG_PID|LOG_CONS, syslog_facility); #else openlog(CS syslog_processname, LOG_CONS, syslog_facility); #endif syslog_open = TRUE; } #endif /* First do a scan through the message in order to determine how many lines it is going to end up as. Then rescan to output it. */ for (pass = 0; pass < 2; pass++) { int i; int tlen; uschar *ss = s; for (i = 1, tlen = len; tlen > 0; i++) { int plen = tlen; uschar *nlptr = Ustrchr(ss, '\n'); if (nlptr != NULL) plen = nlptr - ss; #ifndef SYSLOG_LONG_LINES if (plen > MAX_SYSLOG_LEN) plen = MAX_SYSLOG_LEN; #endif tlen -= plen; if (ss[plen] == '\n') tlen--; /* chars left */ if (pass == 0) linecount++; else { if (linecount == 1) syslog(priority, "%.*s", plen, ss); else syslog(priority, "[%d%c%d] %.*s", i, (ss[plen] == '\n' && tlen != 0)? '\\' : '/', linecount, plen, ss); } ss += plen; if (*ss == '\n') ss++; } } } /************************************************* * Die tidily * *************************************************/ /* This is called when Exim is dying as a result of something going wrong in the logging, or after a log call with LOG_PANIC_DIE set. Optionally write a message to debug_file or a stderr file, if they exist. Then, if in the middle of accepting a message, throw it away tidily by calling receive_bomb_out(); this will attempt to send an SMTP response if appropriate. Passing NULL as the first argument stops it trying to run the NOTQUIT ACL (which might try further logging and thus cause problems). Otherwise, try to close down an outstanding SMTP call tidily. Arguments: s1 Error message to write to debug_file and/or stderr and syslog s2 Error message for any SMTP call that is in progress Returns: The function does not return */ static void die(uschar *s1, uschar *s2) { if (s1 != NULL) { write_syslog(LOG_CRIT, s1); if (debug_file != NULL) debug_printf("%s\n", s1); if (log_stderr != NULL && log_stderr != debug_file) fprintf(log_stderr, "%s\n", s1); } if (receive_call_bombout) receive_bomb_out(NULL, s2); /* does not return */ if (smtp_input) smtp_closedown(s2); exim_exit(EXIT_FAILURE); } /************************************************* * Create a log file * *************************************************/ /* This function is called to create and open a log file. It may be called in a subprocess when the original process is root. Arguments: name the file name The file name has been build in a working buffer, so it is permissible to overwrite it temporarily if it is necessary to create the directory. Returns: a file descriptor, or < 0 on failure (errno set) */ static int create_log(uschar *name) { int fd = Uopen(name, O_CREAT|O_APPEND|O_WRONLY, LOG_MODE); /* If creation failed, attempt to build a log directory in case that is the problem. */ if (fd < 0 && errno == ENOENT) { BOOL created; uschar *lastslash = Ustrrchr(name, '/'); *lastslash = 0; created = directory_make(NULL, name, LOG_DIRECTORY_MODE, FALSE); DEBUG(D_any) debug_printf("%s log directory %s\n", created? "created" : "failed to create", name); *lastslash = '/'; if (created) fd = Uopen(name, O_CREAT|O_APPEND|O_WRONLY, LOG_MODE); } return fd; } /************************************************* * Open a log file * *************************************************/ /* This function opens one of a number of logs, which all (except for the "process log") reside in the same directory, creating the directory if it does not exist. This may be called recursively on failure, in order to open the panic log. The directory is in the static variable file_path. This is static so that it the work of sorting out the path is done just once per Exim process. Exim is normally configured to avoid running as root wherever possible, the log files must be owned by the non-privileged exim user. To ensure this, first try an open without O_CREAT - most of the time this will succeed. If it fails, try to create the file; if running as root, this must be done in a subprocess to avoid races. Arguments: fd where to return the resulting file descriptor type lt_main, lt_reject, lt_panic, lt_debug or lt_process tag optional tag to include in the name (only hooked up for debug) Returns: nothing */ static void open_log(int *fd, int type, uschar *tag) { uid_t euid; BOOL ok, ok2; uschar buffer[LOG_NAME_SIZE]; /* Sort out the file name. This depends on the type of log we are opening. The process "log" is written in the spool directory by default, but a path name can be specified in the configuration. */ if (type == lt_process) { if (process_log_path == NULL) ok = string_format(buffer, sizeof(buffer), "%s/exim-process.info", spool_directory); else ok = string_format(buffer, sizeof(buffer), "%s", process_log_path); } /* The names of the other three logs are controlled by file_path. The panic log is written to the same directory as the main and reject logs, but its name does not have a datestamp. The use of datestamps is indicated by %D/%M in file_path. When opening the panic log, if %D or %M is present, we remove the datestamp from the generated name; if it is at the start, remove a following non-alphanumeric character as well; otherwise, remove a preceding non-alphanumeric character. This is definitely kludgy, but it sort of does what people want, I hope. */ else { ok = string_format(buffer, sizeof(buffer), CS file_path, log_names[type]); /* Save the name of the mainlog for rollover processing. Without a datestamp, it gets statted to see if it has been cycled. With a datestamp, the datestamp will be compared. The static slot for saving it is the same size as buffer, and the text has been checked above to fit, so this use of strcpy() is OK. */ if (type == lt_main) { Ustrcpy(mainlog_name, buffer); mainlog_datestamp = mainlog_name + string_datestamp_offset; } /* Ditto for the reject log */ else if (type == lt_reject) { Ustrcpy(rejectlog_name, buffer); rejectlog_datestamp = rejectlog_name + string_datestamp_offset; } /* and deal with the debug log (which keeps the datestamp, but does not update it) */ else if (type == lt_debug) { Ustrcpy(debuglog_name, buffer); if (tag) { /* this won't change the offset of the datestamp */ ok2 = string_format(buffer, sizeof(buffer), "%s%s", debuglog_name, tag); if (ok2) Ustrcpy(debuglog_name, buffer); } } /* Remove any datestamp if this is the panic log. This is rare, so there's no need to optimize getting the datestamp length. We remove one non-alphanumeric char afterwards if at the start, otherwise one before. */ else if (string_datestamp_offset >= 0) { uschar *from = buffer + string_datestamp_offset; uschar *to = from + string_datestamp_length; if (from == buffer || from[-1] == '/') { if (!isalnum(*to)) to++; } else { if (!isalnum(from[-1])) from--; } /* This strcpy is ok, because we know that to is a substring of from. */ Ustrcpy(from, to); } } /* If the file name is too long, it is an unrecoverable disaster */ if (!ok) { die(US"exim: log file path too long: aborting", US"Logging failure; please try later"); } /* We now have the file name. Try to open an existing file. After a successful open, arrange for automatic closure on exec(), and then return. */ *fd = Uopen(buffer, O_APPEND|O_WRONLY, LOG_MODE); if (*fd >= 0) { (void)fcntl(*fd, F_SETFD, fcntl(*fd, F_GETFD) | FD_CLOEXEC); return; } /* Open was not successful: try creating the file. If this is a root process, we must do the creating in a subprocess set to exim:exim in order to ensure that the file is created with the right ownership. Otherwise, there can be a race if another Exim process is trying to write to the log at the same time. The use of SIGUSR1 by the exiwhat utility can provoke a lot of simultaneous writing. */ euid = geteuid(); /* If we are already running as the Exim user (even if that user is root), we can go ahead and create in the current process. */ if (euid == exim_uid) *fd = create_log(buffer); /* Otherwise, if we are root, do the creation in an exim:exim subprocess. If we are neither exim nor root, creation is not attempted. */ else if (euid == root_uid) { int status, rv; pid_t pid = fork(); /* In the subprocess, change uid/gid and do the creation. Return 0 from the subprocess on success. If we don't check for setuid failures, then the file can be created as root, so vulnerabilities which cause setuid to fail mean that the Exim user can use symlinks to cause a file to be opened/created as root. We always open for append, so can't nuke existing content but it would still be Rather Bad. */ if (pid == 0) { rv = setgid(exim_gid); if (rv) die(US"exim: setgid for log-file creation failed, aborting", US"Unexpected log failure, please try later"); rv = setuid(exim_uid); if (rv) die(US"exim: setuid for log-file creation failed, aborting", US"Unexpected log failure, please try later"); _exit((create_log(buffer) < 0)? 1 : 0); } /* If we created a subprocess, wait for it. If it succeeded retry the open. */ if (pid > 0) { while (waitpid(pid, &status, 0) != pid); if (status == 0) *fd = Uopen(buffer, O_APPEND|O_WRONLY, LOG_MODE); } /* If we failed to create a subprocess, we are in a bad way. We fall through with *fd still < 0, and errno set, letting the code below handle the error. */ } /* If we now have an open file, set the close-on-exec flag and return. */ if (*fd >= 0) { (void)fcntl(*fd, F_SETFD, fcntl(*fd, F_GETFD) | FD_CLOEXEC); return; } /* Creation failed. There are some circumstances in which we get here when the effective uid is not root or exim, which is the problem. (For example, a non-setuid binary with log_arguments set, called in certain ways.) Rather than just bombing out, force the log to stderr and carry on if stderr is available. */ if (euid != root_uid && euid != exim_uid && log_stderr != NULL) { *fd = fileno(log_stderr); return; } /* Otherwise this is a disaster. This call is deliberately ONLY to the panic log. If possible, save a copy of the original line that was being logged. If we are recursing (can't open the panic log either), the pointer will already be set. */ if (panic_save_buffer == NULL) { panic_save_buffer = (uschar *)malloc(LOG_BUFFER_SIZE); if (panic_save_buffer != NULL) memcpy(panic_save_buffer, log_buffer, LOG_BUFFER_SIZE); } log_write(0, LOG_PANIC_DIE, "Cannot open %s log file \"%s\": %s: " "euid=%d egid=%d", log_names[type], buffer, strerror(errno), euid, getegid()); /* Never returns */ } /************************************************* * Add configuration file info to log line * *************************************************/ /* This is put in a function because it's needed twice (once for debugging, once for real). Arguments: ptr pointer to the end of the line we are building flags log flags Returns: updated pointer */ static uschar * log_config_info(uschar *ptr, int flags) { Ustrcpy(ptr, "Exim configuration error"); ptr += 24; if ((flags & (LOG_CONFIG_FOR & ~LOG_CONFIG)) != 0) { Ustrcpy(ptr, " for "); return ptr + 5; } if ((flags & (LOG_CONFIG_IN & ~LOG_CONFIG)) != 0) { sprintf(CS ptr, " in line %d of %s", config_lineno, config_filename); while (*ptr) ptr++; } Ustrcpy(ptr, ":\n "); return ptr + 4; } /************************************************* * A write() operation failed * *************************************************/ /* This function is called when write() fails on anything other than the panic log, which can happen if a disk gets full or a file gets too large or whatever. We try to save the relevant message in the panic_save buffer before crashing out. Arguments: name the name of the log being written length the string length being written rc the return value from write() Returns: does not return */ static void log_write_failed(uschar *name, int length, int rc) { int save_errno = errno; if (panic_save_buffer == NULL) { panic_save_buffer = (uschar *)malloc(LOG_BUFFER_SIZE); if (panic_save_buffer != NULL) memcpy(panic_save_buffer, log_buffer, LOG_BUFFER_SIZE); } log_write(0, LOG_PANIC_DIE, "failed to write to %s: length=%d result=%d " "errno=%d (%s)", name, length, rc, save_errno, (save_errno == 0)? "write incomplete" : strerror(save_errno)); /* Never returns */ } /************************************************* * Write message to log file * *************************************************/ /* Exim can be configured to log to local files, or use syslog, or both. This is controlled by the setting of log_file_path. The following cases are recognized: log_file_path = "" write files in the spool/log directory log_file_path = "xxx" write files in the xxx directory log_file_path = "syslog" write to syslog log_file_path = "syslog : xxx" write to syslog and to files (any order) The one exception to this is messages containing LOG_PROCESS. These are always written to exim-process.info in the spool directory. They aren't really log messages in the same sense as the others. The message always gets '\n' added on the end of it, since more than one process may be writing to the log at once and we don't want intermingling to happen in the middle of lines. To be absolutely sure of this we write the data into a private buffer and then put it out in a single write() call. The flags determine which log(s) the message is written to, or for syslogging, which priority to use, and in the case of the panic log, whether the process should die afterwards. The variable really_exim is TRUE only when exim is running in privileged state (i.e. not with a changed configuration or with testing options such as -brw). If it is not, don't try to write to the log because permission will probably be denied. Avoid actually writing to the logs when exim is called with -bv or -bt to test an address, but take other actions, such as panicing. In Exim proper, the buffer for building the message is got at start-up, so that nothing gets done if it can't be got. However, some functions that are also used in utilities occasionally obey log_write calls in error situations, and it is simplest to put a single malloc() here rather than put one in each utility. Malloc is used directly because the store functions may call log_write(). If a message_id exists, we include it after the timestamp. Arguments: selector write to main log or LOG_INFO only if this value is zero, or if its bit is set in log_write_selector flags each bit indicates some independent action: LOG_SENDER add raw sender to the message LOG_RECIPIENTS add raw recipients list to message LOG_CONFIG add "Exim configuration error" LOG_CONFIG_FOR add " for " instead of ":\n " LOG_CONFIG_IN add " in line x[ of file y]" LOG_MAIN write to main log or syslog LOG_INFO LOG_REJECT write to reject log or syslog LOG_NOTICE LOG_PANIC write to panic log or syslog LOG_ALERT LOG_PANIC_DIE write to panic log or LOG_ALERT and then crash LOG_PROCESS write to process log (always a file) format a printf() format ... arguments for format Returns: nothing */ void log_write(unsigned int selector, int flags, const char *format, ...) { uschar *ptr; int length, rc; int paniclogfd; va_list ap; /* If panic_recurseflag is set, we have failed to open the panic log. This is the ultimate disaster. First try to write the message to a debug file and/or stderr and also to syslog. If panic_save_buffer is not NULL, it contains the original log line that caused the problem. Afterwards, expire. */ if (panic_recurseflag) { uschar *extra = (panic_save_buffer == NULL)? US"" : panic_save_buffer; if (debug_file != NULL) debug_printf("%s%s", extra, log_buffer); if (log_stderr != NULL && log_stderr != debug_file) fprintf(log_stderr, "%s%s", extra, log_buffer); if (*extra != 0) write_syslog(LOG_CRIT, extra); write_syslog(LOG_CRIT, log_buffer); die(US"exim: could not open panic log - aborting: see message(s) above", US"Unexpected log failure, please try later"); } /* Ensure we have a buffer (see comment above); this should never be obeyed when running Exim proper, only when running utilities. */ if (log_buffer == NULL) { log_buffer = (uschar *)malloc(LOG_BUFFER_SIZE); if (log_buffer == NULL) { fprintf(stderr, "exim: failed to get store for log buffer\n"); exim_exit(EXIT_FAILURE); } } /* If we haven't already done so, inspect the setting of log_file_path to determine whether to log to files and/or to syslog. Bits in logging_mode control this, and for file logging, the path must end up in file_path. This variable must be in permanent store because it may be required again later in the process. */ if (!path_inspected) { BOOL multiple = FALSE; int old_pool = store_pool; store_pool = POOL_PERM; /* If nothing has been set, don't waste effort... the default values for the statics are file_path="" and logging_mode = LOG_MODE_FILE. */ if (log_file_path[0] != 0) { int sep = ':'; /* Fixed separator - outside use */ uschar *s; uschar *ss = log_file_path; logging_mode = 0; while ((s = string_nextinlist(&ss,&sep,log_buffer,LOG_BUFFER_SIZE)) != NULL) { if (Ustrcmp(s, "syslog") == 0) logging_mode |= LOG_MODE_SYSLOG; else if ((logging_mode & LOG_MODE_FILE) != 0) multiple = TRUE; else { logging_mode |= LOG_MODE_FILE; /* If a non-empty path is given, use it */ if (s[0] != 0) { file_path = string_copy(s); } /* If the path is empty, we want to use the first non-empty, non- syslog item in LOG_FILE_PATH, if there is one, since the value of log_file_path may have been set at runtime. If there is no such item, use the ultimate default in the spool directory. */ else { uschar *t; uschar *tt = US LOG_FILE_PATH; while ((t = string_nextinlist(&tt,&sep,log_buffer,LOG_BUFFER_SIZE)) != NULL) { if (Ustrcmp(t, "syslog") == 0 || t[0] == 0) continue; file_path = string_copy(t); break; } } /* Empty item in log_file_path */ } /* First non-syslog item in log_file_path */ } /* Scan of log_file_path */ } /* If no modes have been selected, it is a major disaster */ if (logging_mode == 0) die(US"Neither syslog nor file logging set in log_file_path", US"Unexpected logging failure"); /* Set up the ultimate default if necessary. Then revert to the old store pool, and record that we've sorted out the path. */ if ((logging_mode & LOG_MODE_FILE) != 0 && file_path[0] == 0) file_path = string_sprintf("%s/log/%%slog", spool_directory); store_pool = old_pool; path_inspected = TRUE; /* If more than one file path was given, log a complaint. This recursive call should work since we have now set up the routing. */ if (multiple) { log_write(0, LOG_MAIN|LOG_PANIC, "More than one path given in log_file_path: using %s", file_path); } } /* If debugging, show all log entries, but don't show headers. Do it all in one go so that it doesn't get split when multi-processing. */ DEBUG(D_any|D_v) { int i; ptr = log_buffer; Ustrcpy(ptr, "LOG:"); ptr += 4; /* Show the options that were passed into the call. These are those whose flag values do not have the 0x80000000 bit in them. Note that this automatically exclude the "all" setting. */ for (i = 0; i < log_options_count; i++) { unsigned int bit = log_options[i].bit; if ((bit & 0x80000000) != 0) continue; if ((selector & bit) != 0) { *ptr++ = ' '; Ustrcpy(ptr, log_options[i].name); while (*ptr) ptr++; } } sprintf(CS ptr, "%s%s%s%s%s\n ", ((flags & LOG_MAIN) != 0)? " MAIN" : "", ((flags & LOG_PANIC) != 0)? " PANIC" : "", ((flags & LOG_PANIC_DIE) == LOG_PANIC_DIE)? " DIE" : "", ((flags & LOG_PROCESS) != 0)? " PROCESS": "", ((flags & LOG_REJECT) != 0)? " REJECT" : ""); while(*ptr) ptr++; if ((flags & LOG_CONFIG) != 0) ptr = log_config_info(ptr, flags); va_start(ap, format); if (!string_vformat(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer)-1, format, ap)) Ustrcpy(ptr, "**** log string overflowed log buffer ****"); va_end(ap); while(*ptr) ptr++; Ustrcat(ptr, "\n"); debug_printf("%s", log_buffer); } /* If no log file is specified, we are in a mess. */ if ((flags & (LOG_MAIN|LOG_PANIC|LOG_REJECT|LOG_PROCESS)) == 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "log_write called with no log " "flags set"); /* There are some weird circumstances in which logging is disabled. */ if (disable_logging) { DEBUG(D_any) debug_printf("log writing disabled\n"); return; } /* Handle disabled reject log */ if (!write_rejectlog) flags &= ~LOG_REJECT; /* Create the main message in the log buffer, including the message id except for the process log and when called by a utility. */ ptr = log_buffer; sprintf(CS ptr, "%s ", tod_stamp(tod_log)); while(*ptr) ptr++; if ((log_extra_selector & LX_pid) != 0) { sprintf(CS ptr, "[%d] ", (int)getpid()); while (*ptr) ptr++; } if (really_exim && (flags & LOG_PROCESS) == 0 && message_id[0] != 0) { sprintf(CS ptr, "%s ", message_id); while(*ptr) ptr++; } if ((flags & LOG_CONFIG) != 0) ptr = log_config_info(ptr, flags); va_start(ap, format); if (!string_vformat(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer)-1, format, ap)) Ustrcpy(ptr, "**** log string overflowed log buffer ****\n"); while(*ptr) ptr++; va_end(ap); /* Add the raw, unrewritten, sender to the message if required. This is done this way because it kind of fits with LOG_RECIPIENTS. */ if ((flags & LOG_SENDER) != 0 && ptr < log_buffer + LOG_BUFFER_SIZE - 10 - Ustrlen(raw_sender)) { sprintf(CS ptr, " from <%s>", raw_sender); while (*ptr) ptr++; } /* Add list of recipients to the message if required; the raw list, before rewriting, was saved in raw_recipients. There may be none, if an ACL discarded them all. */ if ((flags & LOG_RECIPIENTS) != 0 && ptr < log_buffer + LOG_BUFFER_SIZE - 6 && raw_recipients_count > 0) { int i; sprintf(CS ptr, " for"); while (*ptr) ptr++; for (i = 0; i < raw_recipients_count; i++) { uschar *s = raw_recipients[i]; if (log_buffer + LOG_BUFFER_SIZE - ptr < Ustrlen(s) + 3) break; sprintf(CS ptr, " %s", s); while (*ptr) ptr++; } } sprintf(CS ptr, "\n"); while(*ptr) ptr++; length = ptr - log_buffer; /* Handle loggable errors when running a utility, or when address testing. Write to log_stderr unless debugging (when it will already have been written), or unless there is no log_stderr (expn called from daemon, for example). */ if (!really_exim || log_testing_mode) { if (debug_selector == 0 && log_stderr != NULL && (selector == 0 || (selector & log_write_selector) != 0)) { if (host_checking) fprintf(log_stderr, "LOG: %s", CS(log_buffer + 20)); /* no timestamp */ else fprintf(log_stderr, "%s", CS log_buffer); } if ((flags & LOG_PANIC_DIE) == LOG_PANIC_DIE) exim_exit(EXIT_FAILURE); return; } /* Handle the main log. We know that either syslog or file logging (or both) is set up. A real file gets left open during reception or delivery once it has been opened, but we don't want to keep on writing to it for too long after it has been renamed. Therefore, do a stat() and see if the inode has changed, and if so, re-open. */ if ((flags & LOG_MAIN) != 0 && (selector == 0 || (selector & log_write_selector) != 0)) { if ((logging_mode & LOG_MODE_SYSLOG) != 0 && (syslog_duplication || (flags & (LOG_REJECT|LOG_PANIC)) == 0)) write_syslog(LOG_INFO, log_buffer); if ((logging_mode & LOG_MODE_FILE) != 0) { struct stat statbuf; /* Check for a change to the mainlog file name when datestamping is in operation. This happens at midnight, at which point we want to roll over the file. Closing it has the desired effect. */ if (mainlog_datestamp != NULL) { uschar *nowstamp = tod_stamp(string_datestamp_type); if (Ustrncmp (mainlog_datestamp, nowstamp, Ustrlen(nowstamp)) != 0) { (void)close(mainlogfd); /* Close the file */ mainlogfd = -1; /* Clear the file descriptor */ mainlog_inode = 0; /* Unset the inode */ mainlog_datestamp = NULL; /* Clear the datestamp */ } } /* Otherwise, we want to check whether the file has been renamed by a cycling script. This could be "if else", but for safety's sake, leave it as "if" so that renaming the log starts a new file even when datestamping is happening. */ if (mainlogfd >= 0) { if (Ustat(mainlog_name, &statbuf) < 0 || statbuf.st_ino != mainlog_inode) { (void)close(mainlogfd); mainlogfd = -1; mainlog_inode = 0; } } /* If the log is closed, open it. Then write the line. */ if (mainlogfd < 0) { open_log(&mainlogfd, lt_main, NULL); /* No return on error */ if (fstat(mainlogfd, &statbuf) >= 0) mainlog_inode = statbuf.st_ino; } /* Failing to write to the log is disastrous */ if ((rc = write(mainlogfd, log_buffer, length)) != length) { log_write_failed(US"main log", length, rc); /* That function does not return */ } } } /* Handle the log for rejected messages. This can be globally disabled, in which case the flags are altered above. If there are any header lines (i.e. if the rejection is happening after the DATA phase), log the recipients and the headers. */ if ((flags & LOG_REJECT) != 0) { header_line *h; if (header_list != NULL && (log_extra_selector & LX_rejected_header) != 0) { if (recipients_count > 0) { int i; /* List the sender */ string_format(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer), "Envelope-from: <%s>\n", sender_address); while (*ptr) ptr++; /* List up to 5 recipients */ string_format(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer), "Envelope-to: <%s>\n", recipients_list[0].address); while (*ptr) ptr++; for (i = 1; i < recipients_count && i < 5; i++) { string_format(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer), " <%s>\n", recipients_list[i].address); while (*ptr) ptr++; } if (i < recipients_count) { (void)string_format(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer), " ...\n"); while (*ptr) ptr++; } } /* A header with a NULL text is an unfilled in Received: header */ for (h = header_list; h != NULL; h = h->next) { BOOL fitted; if (h->text == NULL) continue; fitted = string_format(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer), "%c %s", h->type, h->text); while(*ptr) ptr++; if (!fitted) /* Buffer is full; truncate */ { ptr -= 100; /* For message and separator */ if (ptr[-1] == '\n') ptr--; Ustrcpy(ptr, "\n*** truncated ***\n"); while (*ptr) ptr++; break; } } length = ptr - log_buffer; } /* Write to syslog or to a log file */ if ((logging_mode & LOG_MODE_SYSLOG) != 0 && (syslog_duplication || (flags & LOG_PANIC) == 0)) write_syslog(LOG_NOTICE, log_buffer); /* Check for a change to the rejectlog file name when datestamping is in operation. This happens at midnight, at which point we want to roll over the file. Closing it has the desired effect. */ if ((logging_mode & LOG_MODE_FILE) != 0) { struct stat statbuf; if (rejectlog_datestamp != NULL) { uschar *nowstamp = tod_stamp(string_datestamp_type); if (Ustrncmp (rejectlog_datestamp, nowstamp, Ustrlen(nowstamp)) != 0) { (void)close(rejectlogfd); /* Close the file */ rejectlogfd = -1; /* Clear the file descriptor */ rejectlog_inode = 0; /* Unset the inode */ rejectlog_datestamp = NULL; /* Clear the datestamp */ } } /* Otherwise, we want to check whether the file has been renamed by a cycling script. This could be "if else", but for safety's sake, leave it as "if" so that renaming the log starts a new file even when datestamping is happening. */ if (rejectlogfd >= 0) { if (Ustat(rejectlog_name, &statbuf) < 0 || statbuf.st_ino != rejectlog_inode) { (void)close(rejectlogfd); rejectlogfd = -1; rejectlog_inode = 0; } } /* Open the file if necessary, and write the data */ if (rejectlogfd < 0) { open_log(&rejectlogfd, lt_reject, NULL); /* No return on error */ if (fstat(rejectlogfd, &statbuf) >= 0) rejectlog_inode = statbuf.st_ino; } if ((rc = write(rejectlogfd, log_buffer, length)) != length) { log_write_failed(US"reject log", length, rc); /* That function does not return */ } } } /* Handle the process log file, where exim processes can be made to dump details of what they are doing by sending them a USR1 signal. Note that a message id is not automatically added above. This information is always written to a file - never to syslog. */ if ((flags & LOG_PROCESS) != 0) { int processlogfd; open_log(&processlogfd, lt_process, NULL); /* No return on error */ if ((rc = write(processlogfd, log_buffer, length)) != length) { log_write_failed(US"process log", length, rc); /* That function does not return */ } (void)close(processlogfd); } /* Handle the panic log, which is not kept open like the others. If it fails to open, there will be a recursive call to log_write(). We detect this above and attempt to write to the system log as a last-ditch try at telling somebody. In all cases except mua_wrapper, try to write to log_stderr. */ if ((flags & LOG_PANIC) != 0) { if (log_stderr != NULL && log_stderr != debug_file && !mua_wrapper) fprintf(log_stderr, "%s", CS log_buffer); if ((logging_mode & LOG_MODE_SYSLOG) != 0) { write_syslog(LOG_ALERT, log_buffer); } /* If this panic logging was caused by a failure to open the main log, the original log line is in panic_save_buffer. Make an attempt to write it. */ if ((logging_mode & LOG_MODE_FILE) != 0) { panic_recurseflag = TRUE; open_log(&paniclogfd, lt_panic, NULL); /* Won't return on failure */ panic_recurseflag = FALSE; if (panic_save_buffer != NULL) (void) write(paniclogfd, panic_save_buffer, Ustrlen(panic_save_buffer)); if ((rc = write(paniclogfd, log_buffer, length)) != length) { int save_errno = errno; write_syslog(LOG_CRIT, log_buffer); sprintf(CS log_buffer, "write failed on panic log: length=%d result=%d " "errno=%d (%s)", length, rc, save_errno, strerror(save_errno)); write_syslog(LOG_CRIT, log_buffer); flags |= LOG_PANIC_DIE; } (void)close(paniclogfd); } /* Give up if the DIE flag is set */ if ((flags & LOG_PANIC_DIE) != LOG_PANIC) die(NULL, US"Unexpected failure, please try later"); } } /************************************************* * Close any open log files * *************************************************/ void log_close_all(void) { if (mainlogfd >= 0) { (void)close(mainlogfd); mainlogfd = -1; } if (rejectlogfd >= 0) { (void)close(rejectlogfd); rejectlogfd = -1; } closelog(); syslog_open = FALSE; } /************************************************* * Decode bit settings for log/debug * *************************************************/ /* This function decodes a string containing bit settings in the form of +name and/or -name sequences, and sets/unsets bits in a bit string accordingly. It also recognizes a numeric setting of the form =, but this is not intended for user use. It's an easy way for Exim to pass the debug settings when it is re-exec'ed. The log options are held in two unsigned ints (because there became too many for one). The top bit in the table means "put in 2nd selector". This does not yet apply to debug options, so the "=" facility sets only the first selector. The "all" selector, which must be equal to 0xffffffff, is recognized specially. It sets all the bits in both selectors. However, there is a facility for then unsetting certain bits, because we want to turn off "memory" in the debug case. The action taken for bad values varies depending upon why we're here. For log messages, or if the debugging is triggered from config, then we write to the log on the way out. For debug setting triggered from the command-line, we treat it as an unknown option: error message to stderr and die. Arguments: selector1 address of the first bit string selector2 address of the second bit string, or NULL notall1 bits to exclude from "all" for selector1 notall2 bits to exclude from "all" for selector2 string the configured string options the table of option names count size of table which "log" or "debug" flags DEBUG_FROM_CONFIG Returns: nothing on success - bomb out on failure */ void decode_bits(unsigned int *selector1, unsigned int *selector2, int notall1, int notall2, uschar *string, bit_table *options, int count, uschar *which, int flags) { uschar *errmsg; if (string == NULL) return; if (*string == '=') { char *end; /* Not uschar */ *selector1 = strtoul(CS string+1, &end, 0); if (*end == 0) return; errmsg = string_sprintf("malformed numeric %s_selector setting: %s", which, string); goto ERROR_RETURN; } /* Handle symbolic setting */ else for(;;) { BOOL adding; uschar *s; int len; bit_table *start, *end; while (isspace(*string)) string++; if (*string == 0) return; if (*string != '+' && *string != '-') { errmsg = string_sprintf("malformed %s_selector setting: " "+ or - expected but found \"%s\"", which, string); goto ERROR_RETURN; } adding = *string++ == '+'; s = string; while (isalnum(*string) || *string == '_') string++; len = string - s; start = options; end = options + count; while (start < end) { bit_table *middle = start + (end - start)/2; int c = Ustrncmp(s, middle->name, len); if (c == 0) { if (middle->name[len] != 0) c = -1; else { unsigned int bit = middle->bit; unsigned int *selector; /* The value with all bits set means "force all bits in both selectors" in the case where two are being handled. However, the top bit in the second selector is never set. When setting, some bits can be excluded. */ if (bit == 0xffffffff) { if (adding) { *selector1 = 0xffffffff ^ notall1; if (selector2 != NULL) *selector2 = 0x7fffffff ^ notall2; } else { *selector1 = 0; if (selector2 != NULL) *selector2 = 0; } } /* Otherwise, the 0x80000000 bit means "this value, without the top bit, belongs in the second selector". */ else { if ((bit & 0x80000000) != 0) { selector = selector2; bit &= 0x7fffffff; } else selector = selector1; if (adding) *selector |= bit; else *selector &= ~bit; } break; /* Out of loop to match selector name */ } } if (c < 0) end = middle; else start = middle + 1; } /* Loop to match selector name */ if (start >= end) { errmsg = string_sprintf("unknown %s_selector setting: %c%.*s", which, adding? '+' : '-', len, s); goto ERROR_RETURN; } } /* Loop for selector names */ /* Handle disasters */ ERROR_RETURN: if (Ustrcmp(which, "debug") == 0) { if (flags & DEBUG_FROM_CONFIG) { log_write(0, LOG_CONFIG|LOG_PANIC, "%s", errmsg); return; } fprintf(stderr, "exim: %s\n", errmsg); exit(EXIT_FAILURE); } else log_write(0, LOG_CONFIG|LOG_PANIC_DIE, "%s", errmsg); } /************************************************* * Activate a debug logfile (late) * *************************************************/ /* Normally, debugging is activated from the command-line; it may be useful within the configuration to activate debugging later, based on certain conditions. If debugging is already in progress, we return early, no action taken (besides debug-logging that we wanted debug-logging). Failures in options are not fatal but will result in paniclog entries for the misconfiguration. The first use of this is in ACL logic, "control = debug/tag=foo/opts=+expand" which can be combined with conditions, etc, to activate extra logging only for certain sources. */ void debug_logging_activate(uschar *tag_name, uschar *opts) { int fd = -1; if (debug_file) { debug_printf("DEBUGGING ACTIVATED FROM WITHIN CONFIG.\n" "DEBUG: Tag=\"%s\" Opts=\"%s\"\n", tag_name, opts); return; } if (tag_name != NULL && (Ustrchr(tag_name, '/') != NULL)) { log_write(0, LOG_MAIN|LOG_PANIC, "debug tag may not contain a '/' in: %s", tag_name); return; } debug_selector = D_default; if (opts) { decode_bits(&debug_selector, NULL, D_memory, 0, opts, debug_options, debug_options_count, US"debug", DEBUG_FROM_CONFIG); } open_log(&fd, lt_debug, tag_name); if (fd != -1) debug_file = fdopen(fd, "w"); else log_write(0, LOG_MAIN|LOG_PANIC, "unable to open debug log"); } /* End of log.c */