-/* $Cambridge: exim/src/src/transports/appendfile.c,v 1.20 2007/01/08 10:50:20 ph10 Exp $ */
-
/*************************************************
* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2007 */
+/* Copyright (c) University of Cambridge 1995 - 2016 */
/* See the file NOTICE for conditions of use and distribution. */
enum { mbf_unix, mbf_mbx, mbf_smail, mbf_maildir, mbf_mailstore };
-static char *mailbox_formats[] = {
+static const char *mailbox_formats[] = {
"unix", "mbx", "smail", "maildir", "mailstore" };
opt_public flag. */
optionlist appendfile_transport_options[] = {
+#ifdef SUPPORT_MAILDIR
+ { "*expand_maildir_use_size_file", opt_stringptr,
+ (void *)offsetof(appendfile_transport_options_block, expand_maildir_use_size_file) },
+#endif
{ "*set_use_fcntl_lock",opt_bool | opt_hidden,
(void *)offsetof(appendfile_transport_options_block, set_use_fcntl) },
{ "*set_use_flock_lock",opt_bool | opt_hidden,
(void *)offsetof(appendfile_transport_options_block, maildir_retries) },
{ "maildir_tag", opt_stringptr,
(void *)offsetof(appendfile_transport_options_block, maildir_tag) },
- { "maildir_use_size_file", opt_bool,
+ { "maildir_use_size_file", opt_expand_bool,
(void *)offsetof(appendfile_transport_options_block, maildir_use_size_file ) } ,
{ "maildirfolder_create_regex", opt_stringptr,
(void *)offsetof(appendfile_transport_options_block, maildirfolder_create_regex ) },
NULL, /* quota_warn_threshold */
NULL, /* mailbox_size_string */
NULL, /* mailbox_filecount_string */
+ NULL, /* expand_maildir_use_size_file */
US"^(?:cur|new|\\..*)$", /* maildir_dir_regex */
NULL, /* maildir_tag */
NULL, /* maildirfolder_create_regex */
FALSE, /* mailstore_format */
FALSE, /* mbx_format */
FALSE, /* quota_warn_threshold_is_percent */
- TRUE /* quota_is_inclusive */
+ TRUE, /* quota_is_inclusive */
+ FALSE, /* quota_no_check */
+ FALSE /* quota_filecount_no_check */
};
uid = uid;
gid = gid;
+if (ob->expand_maildir_use_size_file)
+ ob->maildir_use_size_file = expand_check_condition(ob->expand_maildir_use_size_file,
+ US"`maildir_use_size_file` in transport", tblock->name);
+
/* Loop for quota, quota_filecount, quota_warn_threshold, mailbox_size,
mailbox_filecount */
for (i = 0; i < 5; i++)
{
double d;
+ int no_check = 0;
uschar *which = NULL;
- if (q == NULL) d = default_value; else
+ if (q == NULL) d = default_value;
+ else
{
uschar *rest;
uschar *s = expand_string(q);
rest++;
}
+
+ /* For quota and quota_filecount there may be options
+ appended. Currently only "no_check", so we can be lazy parsing it */
+ if (i < 2 && Ustrstr(rest, "/no_check") == rest)
+ {
+ no_check = 1;
+ rest += sizeof("/no_check") - 1;
+ }
+
while (isspace(*rest)) rest++;
if (*rest != 0)
{
*errmsg = string_sprintf("Malformed value \"%s\" (expansion of \"%s\") "
- "in %s transport", s, q, tblock->name);
+ "in %s transport [%s]", s, q, tblock->name);
return FAIL;
}
}
case 0:
if (d >= 2.0*1024.0*1024.0*1024.0 && sizeof(off_t) <= 4) which = US"quota";
ob->quota_value = (off_t)d;
+ ob->quota_no_check = no_check;
q = ob->quota_filecount;
break;
case 1:
if (d >= 2.0*1024.0*1024.0*1024.0) which = US"quota_filecount";
ob->quota_filecount_value = (int)d;
+ ob->quota_filecount_no_check = no_check;
q = ob->quota_warn_threshold;
break;
host.address = US"127.0.0.1";
-for (h = &host; h != NULL; h = h->next)
+for (h = &host; h; h = h->next)
{
int sock, rc;
- int host_af = (Ustrchr(h->address, ':') != NULL)? AF_INET6 : AF_INET;
+ int host_af = Ustrchr(h->address, ':') != NULL ? AF_INET6 : AF_INET;
DEBUG(D_transport) debug_printf("calling comsat on %s\n", h->address);
- sock = ip_socket(SOCK_DGRAM, host_af);
- if (sock < 0) continue;
+ if ((sock = ip_socket(SOCK_DGRAM, host_af)) < 0) continue;
/* Connect never fails for a UDP socket, so don't set a timeout. */
- (void)ip_connect(sock, host_af, h->address, ntohs(sp->s_port), 0);
+ (void)ip_connect(sock, host_af, h->address, ntohs(sp->s_port), 0, FALSE);
rc = send(sock, buffer, Ustrlen(buffer) + 1, 0);
(void)close(sock);
transport_instance *
check_file_format(int cfd, transport_instance *tblock, address_item *addr)
{
-uschar *format =
+const uschar *format =
((appendfile_transport_options_block *)(tblock->options_block))->file_format;
uschar data[256];
int len = read(cfd, data, sizeof(data));
/* Search the formats for a match */
-while ((s = string_nextinlist(&format,&sep,big_buffer,big_buffer_size))!= NULL)
+while ((s = string_nextinlist(&format,&sep,big_buffer,big_buffer_size)))
{
int slen = Ustrlen(s);
BOOL match = len >= slen && Ustrncmp(data, s, slen) == 0;
uschar *tp = string_nextinlist(&format, &sep, big_buffer, big_buffer_size);
- if (match)
+
+ if (match && tp)
{
transport_instance *tt;
- for (tt = transports; tt != NULL; tt = tt->next)
+ for (tt = transports; tt; tt = tt->next)
if (Ustrcmp(tp, tt->name) == 0)
{
DEBUG(D_transport)
int used;
off_t size;
struct stat statbuf;
+transport_ctx tctx = {0};
+
+tctx.u.fd = to_fd;
/* If the current mailbox size is zero, write a header block */
(long int)time(NULL));
for (i = 0; i < MBX_NUSERFLAGS; i++)
sprintf (CS(s += Ustrlen(s)), "\015\012");
- if (!transport_write_block (to_fd, deliver_out_buffer, MBX_HDRSIZE))
+ if (!transport_write_block (&tctx, deliver_out_buffer, MBX_HDRSIZE, FALSE))
return DEFER;
}
/* Rewind the temporary file, and copy it over in chunks. */
-lseek(from_fd, 0 , SEEK_SET);
+if (lseek(from_fd, 0 , SEEK_SET) < 0) return DEFER;
while (size > 0)
{
if (len == 0) errno = ERRNO_MBXLENGTH;
return DEFER;
}
- if (!transport_write_block(to_fd, deliver_out_buffer, used + len))
+ if (!transport_write_block(&tctx, deliver_out_buffer, used + len, FALSE))
return DEFER;
size -= len;
used = 0;
Open with O_WRONLY + O_EXCL + O_CREAT with configured mode, unless we know
this is via a symbolic link (only possible if allow_symlinks is set), in
- which case don't use O_EXCL, as it dosn't work.
+ which case don't use O_EXCL, as it doesn't work.
If open fails because the file already exists, go to (6f). To avoid
looping for ever in a situation where the file is continuously being
DEBUG(D_transport)
{
debug_printf("appendfile: mode=%o notify_comsat=%d quota=" OFF_T_FMT
+ "%s%s"
" warning=" OFF_T_FMT "%s\n"
" %s=%s format=%s\n message_prefix=%s\n message_suffix=%s\n "
"maildir_use_size_file=%s\n",
mode, ob->notify_comsat, ob->quota_value,
+ ob->quota_no_check? " (no_check)" : "",
+ ob->quota_filecount_no_check? " (no_check_filecount)" : "",
ob->quota_warn_threshold_value,
ob->quota_warn_threshold_is_percent? "%" : "",
isdirectory? "directory" : "file",
if (ob->use_lockfile)
{
+ /* cf. exim_lock.c */
lockname = string_sprintf("%s.lock", filename);
hitchname = string_sprintf( "%s.%s.%08x.%08x", lockname, primary_hostname,
(unsigned int)(time(NULL)), (unsigned int)getpid());
/* We have successfully created and opened the file. Ensure that the group
and the mode are correct. */
- (void)Uchown(filename, uid, gid);
- (void)Uchmod(filename, mode);
+ if(Uchown(filename, uid, gid) || Uchmod(filename, mode))
+ {
+ addr->basic_errno = errno;
+ addr->message = string_sprintf("while setting perms on mailbox %s",
+ filename);
+ addr->transport_return = FAIL;
+ goto RETURN;
+ }
}
goto RETURN;
}
+ /* Just in case this is a sticky-bit mail directory, we don't want
+ users to be able to create hard links to other users' files. */
+
+ if (statbuf.st_nlink != 1)
+ {
+ addr->basic_errno = ERRNO_NOTREGULAR;
+ addr->message = string_sprintf("mailbox %s%s has too many links (%d)",
+ filename, islink? " (symlink)" : "", statbuf.st_nlink);
+ goto RETURN;
+
+ }
+
/* If symlinks are permitted (not recommended), the lstat() above will
have found the symlink. Its ownership has just been checked; go round
the loop again, using stat() instead of lstat(). That will never yield a
#ifdef SUPPORT_MBX
else if (ob->use_mbx_lock)
{
+ int mbx_tmp_oflags;
+ struct stat lstatbuf, statbuf2;
if (apply_lock(fd, F_RDLCK, ob->use_fcntl, ob->lock_fcntl_timeout,
ob->use_flock, ob->lock_flock_timeout) >= 0 &&
fstat(fd, &statbuf) >= 0)
sprintf(CS mbx_lockname, "/tmp/.%lx.%lx", (long)statbuf.st_dev,
(long)statbuf.st_ino);
+ /*
+ * 2010-05-29: SECURITY
+ * Dan Rosenberg reported the presence of a race-condition in the
+ * original code here. Beware that many systems still allow symlinks
+ * to be followed in /tmp so an attacker can create a symlink pointing
+ * elsewhere between a stat and an open, which we should avoid
+ * following.
+ *
+ * It's unfortunate that we can't just use all the heavily debugged
+ * locking from above.
+ *
+ * Also: remember to mirror changes into exim_lock.c */
+
+ /* first leave the old pre-check in place, it provides better
+ * diagnostics for common cases */
if (Ulstat(mbx_lockname, &statbuf) >= 0)
{
if ((statbuf.st_mode & S_IFMT) == S_IFLNK)
}
}
- mbx_lockfd = Uopen(mbx_lockname, O_RDWR | O_CREAT, ob->lockfile_mode);
+ /* If we could just declare "we must be the ones who create this
+ * file" then a hitching post in a subdir would work, since a
+ * subdir directly in /tmp/ which we create wouldn't follow links
+ * but this isn't our locking logic, so we can't safely change the
+ * file existence rules. */
+
+ /* On systems which support O_NOFOLLOW, it's the easiest and most
+ * obviously correct security fix */
+ mbx_tmp_oflags = O_RDWR | O_CREAT;
+#ifdef O_NOFOLLOW
+ mbx_tmp_oflags |= O_NOFOLLOW;
+#endif
+ mbx_lockfd = Uopen(mbx_lockname, mbx_tmp_oflags, ob->lockfile_mode);
if (mbx_lockfd < 0)
{
addr->basic_errno = ERRNO_LOCKFAILED;
goto RETURN;
}
+ if (Ulstat(mbx_lockname, &lstatbuf) < 0)
+ {
+ addr->basic_errno = ERRNO_LOCKFAILED;
+ addr->message = string_sprintf("attempting to lstat open MBX "
+ "lock file %s: %s", mbx_lockname, strerror(errno));
+ goto RETURN;
+ }
+ if (fstat(mbx_lockfd, &statbuf2) < 0)
+ {
+ addr->basic_errno = ERRNO_LOCKFAILED;
+ addr->message = string_sprintf("attempting to stat fd of open MBX "
+ "lock file %s: %s", mbx_lockname, strerror(errno));
+ goto RETURN;
+ }
+
+ /*
+ * At this point:
+ * statbuf: if exists, is file which existed prior to opening the
+ * lockfile, might have been replaced since then
+ * statbuf2: result of stat'ing the open fd, is what was actually
+ * opened
+ * lstatbuf: result of lstat'ing the filename immediately after
+ * the open but there's a race condition again between
+ * those two steps: before open, symlink to foo, after
+ * open but before lstat have one of:
+ * * was no symlink, so is the opened file
+ * (we created it, no messing possible after that point)
+ * * hardlink to foo
+ * * symlink elsewhere
+ * * hardlink elsewhere
+ * * new file/other
+ * Don't want to compare to device of /tmp because some modern systems
+ * have regressed to having /tmp be the safe actual filesystem as
+ * valuable data, so is mostly worthless, unless we assume that *only*
+ * Linux systems do this and that all Linux has O_NOFOLLOW. Something
+ * for further consideration.
+ * No point in doing a readlink on the lockfile as that will always be
+ * at a different point in time from when we open it, so tells us
+ * nothing; attempts to clean up and delete after ourselves would risk
+ * deleting a *third* filename.
+ */
+ if ((statbuf2.st_nlink > 1) ||
+ (lstatbuf.st_nlink > 1) ||
+ (!S_ISREG(lstatbuf.st_mode)) ||
+ (lstatbuf.st_dev != statbuf2.st_dev) ||
+ (lstatbuf.st_ino != statbuf2.st_ino))
+ {
+ addr->basic_errno = ERRNO_LOCKFAILED;
+ addr->message = string_sprintf("RACE CONDITION detected: "
+ "mismatch post-initial-checks between \"%s\" and opened "
+ "fd lead us to abort!", mbx_lockname);
+ goto RETURN;
+ }
+
(void)Uchmod(mbx_lockname, ob->lockfile_mode);
if (apply_lock(mbx_lockfd, F_WRLCK, ob->use_fcntl,
"%s/maildirsize", check_path);
return FALSE;
}
+ /* can also return -2, which means that the file was removed because of
+ raciness; but in this case, the size & filecount will still have been
+ updated. */
if (mailbox_size < 0) mailbox_size = size;
if (mailbox_filecount < 0) mailbox_filecount = filecount;
uschar *basename;
(void)gettimeofday(&msg_tv, NULL);
- basename = string_sprintf("%lu.H%luP%lu.%s", msg_tv.tv_sec,
- msg_tv.tv_usec, getpid(), primary_hostname);
+ basename = string_sprintf(TIME_T_FMT ".H%luP%lu.%s",
+ msg_tv.tv_sec, msg_tv.tv_usec, getpid(), primary_hostname);
filename = dataname = string_sprintf("tmp/%s", basename);
newname = string_sprintf("new/%s", basename);
addr->message = string_sprintf ("failed to open %s (%d tr%s)",
filename, i, (i == 1)? "y" : "ies");
addr->basic_errno = errno;
+ if (errno == errno_quota || errno == ENOSPC)
+ addr->user_message = US"mailbox is full";
return FALSE;
}
/* Why are these here? Put in because they are present in the non-maildir
directory case above. */
- (void)Uchown(filename, uid, gid);
- (void)Uchmod(filename, mode);
+ if(Uchown(filename, uid, gid) || Uchmod(filename, mode))
+ {
+ addr->basic_errno = errno;
+ addr->message = string_sprintf("while setting perms on maildir %s",
+ filename);
+ return FALSE;
+ }
}
#endif /* SUPPORT_MAILDIR */
/* Why are these here? Put in because they are present in the non-maildir
directory case above. */
- (void)Uchown(filename, uid, gid);
- (void)Uchmod(filename, mode);
+ if(Uchown(filename, uid, gid) || Uchmod(filename, mode))
+ {
+ addr->basic_errno = errno;
+ addr->message = string_sprintf("while setting perms on file %s",
+ filename);
+ return FALSE;
+ }
/* Built a C stream from the open file descriptor. */
Uunlink(filename);
return FALSE;
}
- (void)Uchown(dataname, uid, gid);
- (void)Uchmod(dataname, mode);
+ if(Uchown(dataname, uid, gid) || Uchmod(dataname, mode))
+ {
+ addr->basic_errno = errno;
+ addr->message = string_sprintf("while setting perms on file %s",
+ dataname);
+ return FALSE;
+ }
}
#endif /* SUPPORT_MAILSTORE */
/* In all cases of writing to a new file, ensure that the file which is
going to be renamed has the correct ownership and mode. */
- (void)Uchown(filename, uid, gid);
- (void)Uchmod(filename, mode);
+ if(Uchown(filename, uid, gid) || Uchmod(filename, mode))
+ {
+ addr->basic_errno = errno;
+ addr->message = string_sprintf("while setting perms on file %s",
+ filename);
+ return FALSE;
+ }
}
debug_printf(" file count quota = %d count = %d\n",
ob->quota_filecount_value, mailbox_filecount);
}
+
if (mailbox_size + (ob->quota_is_inclusive? message_size:0) > ob->quota_value)
{
- DEBUG(D_transport) debug_printf("mailbox quota exceeded\n");
- yield = DEFER;
- errno = ERRNO_EXIMQUOTA;
- }
- else if (ob->quota_filecount_value > 0 &&
- mailbox_filecount + (ob->quota_is_inclusive ? 1:0) >
- ob->quota_filecount_value)
- {
- DEBUG(D_transport) debug_printf("mailbox file count quota exceeded\n");
- yield = DEFER;
- errno = ERRNO_EXIMQUOTA;
- filecount_msg = US" filecount";
+
+ if (!ob->quota_no_check)
+ {
+ DEBUG(D_transport) debug_printf("mailbox quota exceeded\n");
+ yield = DEFER;
+ errno = ERRNO_EXIMQUOTA;
+ }
+ else DEBUG(D_transport) debug_printf("mailbox quota exceeded but ignored\n");
+
}
+
+ if (ob->quota_filecount_value > 0
+ && mailbox_filecount + (ob->quota_is_inclusive ? 1:0) >
+ ob->quota_filecount_value)
+ if(!ob->quota_filecount_no_check)
+ {
+ DEBUG(D_transport) debug_printf("mailbox file count quota exceeded\n");
+ yield = DEFER;
+ errno = ERRNO_EXIMQUOTA;
+ filecount_msg = US" filecount";
+ }
+ else DEBUG(D_transport) if (ob->quota_filecount_no_check)
+ debug_printf("mailbox file count quota exceeded but ignored\n");
+
}
/* If we are writing in MBX format, what we actually do is to write the message
functions. */
transport_count = 0;
+transport_newlines = 0;
/* Write any configured prefix text first */
if (yield == OK && ob->use_bsmtp)
{
transport_count = 0;
+ transport_newlines = 0;
if (ob->use_crlf) cr = US"\r";
if (!transport_write_string(fd, "MAIL FROM:<%s>%s\n", return_path, cr))
yield = DEFER;
else
{
address_item *a;
+ transport_newlines++;
for (a = addr; a != NULL; a = a->next)
{
address_item *b = testflag(a, af_pfr)? a->parent: a;
if (!transport_write_string(fd, "RCPT TO:<%s>%s\n",
transport_rcpt_address(b, tblock->rcpt_include_affixes), cr))
{ yield = DEFER; break; }
+ transport_newlines++;
}
if (yield == OK && !transport_write_string(fd, "DATA%s\n", cr))
yield = DEFER;
+ else
+ transport_newlines++;
}
}
if (yield == OK)
{
- if (!transport_write_message(addr, fd, ob->options, 0, tblock->add_headers,
- tblock->remove_headers, ob->check_string, ob->escape_string,
- tblock->rewrite_rules, tblock->rewrite_existflags))
+ transport_ctx tctx = {
+ fd,
+ tblock,
+ addr,
+ ob->check_string,
+ ob->escape_string,
+ ob->options
+ };
+ if (!transport_write_message(&tctx, 0))
yield = DEFER;
}
/* If batch smtp, write the terminating dot. */
-if (yield == OK && ob->use_bsmtp &&
- !transport_write_string(fd, ".%s\n", cr)) yield = DEFER;
+if (yield == OK && ob->use_bsmtp ) {
+ if(!transport_write_string(fd, ".%s\n", cr)) yield = DEFER;
+ else transport_newlines++;
+}
/* If MBX format is being used, all that writing was to the temporary file.
However, if there was an earlier failure (Exim quota exceeded, for example),
if (yield == OK)
{
transport_count = 0; /* Reset transport count for actual write */
+ /* No need to reset transport_newlines as we're just using a block copy
+ * routine so the number won't be affected */
yield = copy_mbx_message(fd, fileno(temp_file), saved_size);
}
else if (errno >= 0) dataname = US"temporary file";
/* Force out the remaining data to check for any errors; some OS don't allow
fsync() to be called for a FIFO. */
-if (yield == OK && !isfifo && fsync(fd) < 0) yield = DEFER;
+if (yield == OK && !isfifo && EXIMfsync(fd) < 0) yield = DEFER;
-/* Update message_size to the accurate count of bytes written, including
-added headers. */
+/* Update message_size and message_linecount to the accurate count of bytes
+written, including added headers. Note; we subtract 1 from message_linecount as
+this variable doesn't count the new line between the header and the body of the
+message. */
message_size = transport_count;
+message_linecount = transport_newlines - 1;
/* If using a maildir++ quota file, add this message's size to it, and
close the file descriptor, except when the quota has been disabled because we
if (yield == OK && maildirsize_fd >= 0)
maildir_record_length(maildirsize_fd, message_size);
maildir_save_errno = errno; /* Preserve errno while closing the file */
- (void)close(maildirsize_fd);
+ if (maildirsize_fd >= 0)
+ (void)close(maildirsize_fd);
errno = maildir_save_errno;
}
#endif /* SUPPORT_MAILDIR */
#else
addr->message = string_sprintf("mailbox is full");
#endif /* EDQUOT */
+ addr->user_message = US"mailbox is full";
DEBUG(D_transport) debug_printf("System quota exceeded for %s%s%s\n",
dataname,
isdirectory? US"" : US": time since file read = ",
investigated so far have ftruncate(), whereas not all have the F_FREESP
fcntl() call (BSDI & FreeBSD do not). */
- if (!isdirectory) (void)ftruncate(fd, saved_size);
+ if (!isdirectory && ftruncate(fd, saved_size))
+ DEBUG(D_transport) debug_printf("Error resetting file size\n");
}
/* Handle successful writing - we want the modification time to be now for
projects / exim.git / blobdiff