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/* $Cambridge: exim/exim-src/src/transports/tf_maildir.c,v 1.14 2009/11/16 19:56:54 nm4 Exp $ */
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/*************************************************
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* Exim - an Internet mail transport agent *
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*************************************************/
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/* Copyright (c) University of Cambridge 1995 - 2009 */
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/* See the file NOTICE for conditions of use and distribution. */
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/* Functions in support of the use of maildirsize files for handling quotas in
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maildir directories. Some of the rules are a bit baroque:
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http://www.inter7.com/courierimap/README.maildirquota.html
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We try to follow most of that, except that the directories to skip for quota
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calculations are not hard wired in, but are supplied as a regex. */
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#include "appendfile.h"
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#include "tf_maildir.h"
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#define MAX_FILE_SIZE 5120
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/*************************************************
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* Ensure maildir directories exist *
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*************************************************/
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/* This function is called at the start of a maildir delivery, to ensure that
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all the relevant directories exist. It also creates a maildirfolder file if the
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base directory matches a given pattern.
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path the base directory name
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addr the address item (for setting an error message)
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create_directory true if we are allowed to create missing directories
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dirmode the mode for created directories
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maildirfolder_create_regex
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the pattern to match for maildirfolder creation
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Returns: TRUE on success; FALSE on failure
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BOOL maildir_ensure_directories(uschar *path, address_item *addr,
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BOOL create_directory, int dirmode, uschar *maildirfolder_create_regex)
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char *subdirs[] = { "/tmp", "/new", "/cur" };
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debug_printf("ensuring maildir directories exist in %s\n", path);
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/* First ensure that the path we have is a directory; if it does not exist,
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create it. Then make sure the tmp, new & cur subdirs of the maildir are
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there. If not, fail. This aborts the delivery (even though the cur subdir is
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not actually needed for delivery). Handle all 4 directory tests/creates in a
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loop so that code can be shared. */
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for (i = 0; i < 4; i++)
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mdir = US subdirs[i-1];
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/* Check an existing path is a directory. This is inside a loop because
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there is a potential race condition when creating the directory - some
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other process may get there first. Give up after trying several times,
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for (j = 0; j < 10; j++)
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if (Ustat(dir, &statbuf) == 0)
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if (S_ISDIR(statbuf.st_mode)) break; /* out of the race loop */
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addr->message = string_sprintf("%s%s is not a directory", path,
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addr->basic_errno = ERRNO_NOTDIRECTORY;
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/* Try to make if non-existent and configured to do so */
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if (errno == ENOENT && create_directory)
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if (!directory_make(NULL, dir, dirmode, FALSE))
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if (errno == EEXIST) continue; /* repeat the race loop */
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addr->message = string_sprintf("cannot create %s%s", path, mdir);
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addr->basic_errno = errno;
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debug_printf("created directory %s%s\n", path, mdir);
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break; /* out of the race loop */
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/* stat() error other than ENOENT, or ENOENT and not creatable */
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addr->message = string_sprintf("stat() error for %s%s: %s", path, mdir,
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addr->basic_errno = errno;
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/* If we went round the loop 10 times, the directory was flickering in
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and out of existence like someone in a malfunctioning Star Trek
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addr->message = string_sprintf("existence of %s%s unclear\n", path,
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addr->basic_errno = errno;
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addr->special_action = SPECIAL_FREEZE;
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/* First time through the directories loop, cd to the main directory */
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if (i == 0 && Uchdir(path) != 0)
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addr->message = string_sprintf ("cannot chdir to %s", path);
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addr->basic_errno = errno;
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/* If the basic path matches maildirfolder_create_regex, we are dealing with
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a subfolder, and should ensure that a maildirfolder file exists. */
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if (maildirfolder_create_regex != NULL)
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DEBUG(D_transport) debug_printf("checking for maildirfolder requirement\n");
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regex = pcre_compile(CS maildirfolder_create_regex, PCRE_COPT,
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(const char **)&error, &offset, NULL);
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addr->message = string_sprintf("appendfile: regular expression "
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"error: %s at offset %d while compiling %s", error, offset,
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maildirfolder_create_regex);
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if (pcre_exec(regex, NULL, CS path, Ustrlen(path), 0, 0, NULL, 0) >= 0)
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uschar *fname = string_sprintf("%s/maildirfolder", path);
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if (Ustat(fname, &statbuf) == 0)
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DEBUG(D_transport) debug_printf("maildirfolder already exists\n");
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int fd = Uopen(fname, O_WRONLY|O_APPEND|O_CREAT, 0600);
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addr->message = string_sprintf("appendfile: failed to create "
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"maildirfolder file in %s directory: %s", path, strerror(errno));
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DEBUG(D_transport) debug_printf("created maildirfolder file\n");
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DEBUG(D_transport) debug_printf("maildirfolder file not required\n");
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return TRUE; /* Everything exists that should exist */
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/*************************************************
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* Update maildirsizefile for new file *
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*************************************************/
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/* This function is called to add a new line to the file, recording the length
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of the newly added message. There isn't much we can do on failure...
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fd the open file descriptor
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size the size of the message
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maildir_record_length(int fd, int size)
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sprintf(CS buffer, "%d 1\n", size);
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len = Ustrlen(buffer);
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(void)lseek(fd, 0, SEEK_END);
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(void)write(fd, buffer, len);
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debug_printf("added '%.*s' to maildirsize file\n", len-1, buffer);
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/*************************************************
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* Find the size of a maildir *
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*************************************************/
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/* This function is called when we have to recalculate the size of a maildir by
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scanning all the files and directories therein. There are rules and conventions
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about which files or directories are included. We support this by the use of a
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regex to match directories that are to be included.
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Maildirs can only be one level deep. However, this function recurses, so it
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might cope with deeper nestings. We use the existing check_dir_size() function
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to add up the sizes of the files in a directory that contains messages.
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The function returns the most recent timestamp encountered. It can also be run
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in a dummy mode in which it does not scan for sizes, but just returns the
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path the path to the maildir
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filecount where to store the count of messages
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latest where to store the latest timestamp encountered
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regex a regex for getting files sizes from file names
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dir_regex a regex for matching directories to be included
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timestamp_only don't actually compute any sizes
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Returns: the sum of the sizes of the messages
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maildir_compute_size(uschar *path, int *filecount, time_t *latest,
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const pcre *regex, const pcre *dir_regex, BOOL timestamp_only)
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dir = opendir(CS path);
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if (dir == NULL) return 0;
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while ((ent = readdir(dir)) != NULL)
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uschar *name = US ent->d_name;
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if (Ustrcmp(name, ".") == 0 || Ustrcmp(name, "..") == 0) continue;
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/* We are normally supplied with a regex for choosing which directories to
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scan. We do the regex match first, because that avoids a stat() for names
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we aren't interested in. */
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if (dir_regex != NULL &&
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pcre_exec(dir_regex, NULL, CS name, Ustrlen(name), 0, 0, NULL, 0) < 0)
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debug_printf("skipping %s/%s: dir_regex does not match\n", path, name);
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/* The name is OK; stat it. */
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if (!string_format(buffer, sizeof(buffer), "%s/%s", path, name))
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debug_printf("maildir_compute_size: name too long: dir=%s name=%s\n",
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if (Ustat(buffer, &statbuf) < 0)
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debug_printf("maildir_compute_size: stat error %d for %s: %s\n", errno,
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buffer, strerror(errno));
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if ((statbuf.st_mode & S_IFMT) != S_IFDIR)
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debug_printf("skipping %s/%s: not a directory\n", path, name);
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/* Keep the latest timestamp encountered */
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if (statbuf.st_mtime > *latest) *latest = statbuf.st_mtime;
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/* If this is a maildir folder, call this function recursively. */
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sum += maildir_compute_size(buffer, filecount, latest, regex, dir_regex,
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/* Otherwise it must be a folder that contains messages (e.g. new or cur), so
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we need to get its size, unless all we are interested in is the timestamp. */
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else if (!timestamp_only)
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sum += check_dir_size(buffer, filecount, regex);
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debug_printf("maildir_compute_size (timestamp_only): %ld\n",
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debug_printf("maildir_compute_size: path=%s\n sum=" OFF_T_FMT
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" filecount=%d timestamp=%ld\n",
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path, sum, *filecount, (long int) *latest);
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/*************************************************
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* Create or update maildirsizefile *
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*************************************************/
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/* This function is called before a delivery if the option to use
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maildirsizefile is enabled. Its function is to create the file if it does not
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exist, or to update it if that is necessary.
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The logic in this function follows the rules that are described in
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http://www.inter7.com/courierimap/README.maildirquota.html
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Or, at least, it is supposed to!
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path the path to the maildir directory; this is already backed-up
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to the parent if the delivery diretory is a maildirfolder
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ob the appendfile options block
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regex a compiled regex for getting a file's size from its name
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dir_regex a compiled regex for selecting maildir directories
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returned_size where to return the current size of the maildir, even if
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the maildirsizefile is removed because of a race
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Returns: >=0 a file descriptor for an open maildirsize file
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-1 there was an error opening or accessing the file
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-2 the file was removed because of a race
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maildir_ensure_sizefile(uschar *path, appendfile_transport_options_block *ob,
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const pcre *regex, const pcre *dir_regex, off_t *returned_size,
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int *returned_filecount)
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off_t cached_quota = 0;
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int cached_quota_filecount = 0;
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uschar buffer[MAX_FILE_SIZE];
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uschar *ptr = buffer;
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/* Try a few times to open or create the file, in case another process is doing
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filename = string_sprintf("%s/maildirsize", path);
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DEBUG(D_transport) debug_printf("looking for maildirsize in %s\n", path);
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fd = Uopen(filename, O_RDWR|O_APPEND, ob->mode ? ob->mode : 0600);
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if (errno != ENOENT) return -1;
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debug_printf("%s does not exist: recalculating\n", filename);
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/* The file has been successfully opened. Check that the cached quota value is
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still correct, and that the size of the file is still small enough. If so,
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compute the maildir size from the file. */
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count = read(fd, buffer, sizeof(buffer));
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if (count >= sizeof(buffer))
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debug_printf("maildirsize file too big (%d): recalculating\n", count);
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buffer[count] = 0; /* Ensure string terminated */
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/* Read the quota parameters from the first line of the data. */
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debug_printf("reading quota parameters from maildirsize data\n");
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off_t n = (off_t)Ustrtod(ptr, &endptr);
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/* Only two data items are currently defined; ignore any others that
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may be present. The spec is for a number followed by a letter. Anything
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else we reject and recalculate. */
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if (*endptr == 'S') cached_quota = n;
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else if (*endptr == 'C') cached_quota_filecount = (int)n;
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if (!isalpha(*endptr++))
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debug_printf("quota parameter number not followed by letter in "
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"\"%.*s\": recalculating maildirsize\n", (int)(endptr - buffer),
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if (*endptr == '\n' || *endptr == 0) break;
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if (*endptr++ != ',')
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debug_printf("quota parameter not followed by comma in "
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"\"%.*s\": recalculating maildirsize\n", (int)(endptr - buffer),
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/* Check the cached values against the current settings */
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if (cached_quota != ob->quota_value ||
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cached_quota_filecount != ob->quota_filecount_value)
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debug_printf("cached quota is out of date: recalculating\n"
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" quota=" OFF_T_FMT " cached_quota=" OFF_T_FMT " filecount_quota=%d "
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"cached_quota_filecount=%d\n", ob->quota_value,
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cached_quota, ob->quota_filecount_value, cached_quota_filecount);
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/* Quota values agree; parse the rest of the data to get the sizes. At this
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stage, *endptr points either to 0 or to '\n'. */
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debug_printf("computing maildir size from maildirsize data\n");
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while (*endptr++ == '\n')
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if (*endptr == 0) break;
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size += (off_t)Ustrtod(ptr, &endptr);
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if (*endptr != ' ') break;
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filecount += Ustrtol(ptr, &endptr, 10);
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/* If *endptr is zero, we have successfully parsed the file, and we now have
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the size of the mailbox as cached in the file. The "rules" say that if this
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value indicates that the mailbox is over quota, we must recalculate if there is
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more than one entry in the file, or if the file is older than 15 minutes. Also,
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just in case there are weird values in the file, recalculate if either of the
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values is negative. */
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if (size < 0 || filecount < 0)
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DEBUG(D_transport) debug_printf("negative value in maildirsize "
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"(size=" OFF_T_FMT " count=%d): recalculating\n", size, filecount);
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if (ob->quota_value > 0 &&
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(size + (ob->quota_is_inclusive? message_size : 0) > ob->quota_value ||
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(ob->quota_filecount_value > 0 &&
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filecount + (ob->quota_is_inclusive ? 1:0) >
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ob->quota_filecount_value)
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DEBUG(D_transport) debug_printf("over quota and maildirsize has "
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"more than 1 entry: recalculating\n");
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if (fstat(fd, &statbuf) < 0) goto RECALCULATE; /* Should never occur */
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if (time(NULL) - statbuf.st_mtime > 15*60)
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DEBUG(D_transport) debug_printf("over quota and maildirsize is older "
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"than 15 minutes: recalculating\n");
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/* If *endptr is not zero, there was a syntax error in the file. */
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time_t old_latest, new_latest;
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while (p > buffer && p[-1] != '\n') p--;
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debug_printf("error in maildirsizefile: unexpected character %d in "
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"line %d (starting '%s'): recalculating\n",
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*endptr, linecount + 1, string_printing(p));
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/* Either there is no file, or the quota value has changed, or the file has
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got too big, or there was some format error in the file. Recalculate the size
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and write new contents to a temporary file; then rename it. After any
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error, just return -1 as the file descriptor. */
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if (fd >= 0) (void)close(fd);
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size = maildir_compute_size(path, &filecount, &old_latest, regex, dir_regex,
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(void)gettimeofday(&tv, NULL);
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tempname = string_sprintf("%s/tmp/%lu.H%luP%lu.%s", path, tv.tv_sec,
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tv.tv_usec, getpid(), primary_hostname);
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fd = Uopen(tempname, O_RDWR|O_CREAT|O_EXCL, ob->mode ? ob->mode : 0600);
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(void)sprintf(CS buffer, OFF_T_FMT "S,%dC\n" OFF_T_FMT " %d\n",
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ob->quota_value, ob->quota_filecount_value, size, filecount);
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len = Ustrlen(buffer);
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if (write(fd, buffer, len) != len || Urename(tempname, filename) < 0)
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/* If any of the directories have been modified since the last timestamp we
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saw, we have to junk this maildirsize file. */
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DEBUG(D_transport) debug_printf("checking subdirectory timestamps\n");
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(void)maildir_compute_size(path, NULL, &new_latest , NULL, dir_regex, TRUE);
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if (new_latest > old_latest)
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DEBUG(D_transport) debug_printf("abandoning maildirsize because of "
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"a later subdirectory modification\n");
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(void)Uunlink(filename);
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/* Return the sizes and the file descriptor, if any */
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DEBUG(D_transport) debug_printf("returning maildir size=" OFF_T_FMT
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" filecount=%d\n", size, filecount);
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*returned_size = size;
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*returned_filecount = filecount;
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/* End of tf_maildir.c */
added
removed
src/transports/tf_maildir.c
