from accept(2) and fork(2). Also close all unneeded fds
in the child process, namely listening sockets for all
address families and the fd initially obtained from accept(2).
(The main ftpd code operates on stdin/stdout anyway as it
has been designed for running from inetd.)
MFC after: 5 days
By default, create a pid file at the standard location, /var/run/ftpd.pid,
in accord with the expected behavior of a stock system daemon.
MFC after: 5 days
The major change is to process STAT sent as an OOB command w/o
breaking the current data transfer. As a side effect, this gives
better error checking in the code performing data transfers.
A lesser, but in no way cosmetic, change is using the flag `recvurg'
in the only signal-safe way that has been blessed by SUSv3. The
other flag, `transflag,' becomes private to the SIGURG machinery,
serves debugging purposes only, and may be dropped in the future.
The `byte_count' global variable is now accounting bytes actually
transferred over the network. This can give status messages looking
strange, like "X of Y bytes transferred," where X > Y, but that has
more sense than trying to compensate for combinations of data formats
on the server and client when transferring ASCII type data. BTW,
getting the size of a file in advance is unreliable for a number of
reasons in the first place. See question 18.8 of the Infrequently
Asked Questions in comp.lang.c for details.
PR: bin/52072
Tested by: Nick Leuta (earlier versions), a stress-testing tool (final)
MFC after: 1 month
When in inetd mode, this prevents bogus messages from
appearing on the control channel. When running as a
daemon, we shouldn't write to the terminal we used to
have at all.
PR: bin/74823
MFC after: 1 week
Log it once at the beginning of the session instead. OTOH, log wd each
time for the sake of better auditing and consistent log format.
Proposed by: Nick Leuta <skynick -at- mail.sc.ru>
add the working directory pathname to the log message if any of
such arguments isn't absolute. This has advantage over the old
way of logging that an admin can see what users are actually trying
to do, and where. The old code was also not too robust when it
came to a chrooted session and an absolute pathname.
Pointed out by: Nick Leuta
MFC after: 2 weeks
The size_t type is better suited for that, particularly because
the "blksize" argument is to be passed to malloc() and read().
On 64-bit archs it's more to a style issue, but the good style
of coding in C is also important.
Previously logxfer() used to record bogus pathnames to the log
in some cases, namely, when cwd was / or "name" was absolute.
Noticed by: Nick Leuta
MFC after: 2 weeks
that the creation of a PAM context has failed.
N.B. This does not apply to pam_strerror() in RELENG_4, it
will mishandle a NULL "pamh".
Discussed with: des
instead of the disk size of the file sent. Since the log file
is intended to provide data for anonymous ftp traffic accounting,
the disk size of the file isn't really informative in this case.
PR: bin/72687
Submitted by: Oleg Koreshkov
MFC after: 1 week
if sendfile() transferred some data before throwing
a error condition because sendfile() won't move the
file offset for read() to start from.
MFC after: 2 weeks
Do not unconditionally fork() after accept(). accept() can
return -1 due to an interrupted system call (i.e. SIGCHLD).
If we fork in that case ftpd can get into an
accept()/SIGCHLD/fork/[fail]/repeat loop.
Reported-by: fabian <fabian.duelli@bluewin.ch>
Obtained from: DragonflyBSD
MFC after: 1 month
(and it appears possible throughout ftpd(8) source.)
It is not a mere issue of style: Null pointers in C
seem to have been mistaken one way or another quite often.
of the current user, not root. This will allow neat things
like matching anonymous FTP data traffic with a single ipfw(8)
rule:
ipfw add ... tcp from any to any uid ftp
Note that the control connection socket still belongs to the
user ftpd(8) was started from, usually root.
PR: bin/65928
Submitted by: Eugene Grosbein <eugen at grosbein.pp.ru>
MFC after: 1 month
says they may not modify existing files through FTP.
Renaming a file is effectively a way to modify it.
For instance, if a malicious party is unable to delete or overwrite
a sensitive file, they can nevertheless rename it to a hidden name
and then upload a troyan horse under the guise of the old file name.
contents in reply to a RETR command. Such clients consider RETR
as a way to tell a file from a directory. Mozilla is an example.
PR: bin/62232
Submitted by: Bob Finch <bob+freebsd <at> nas <dot> com>
MFC after: 1 week
However, the code did allow deletion of files. Make deleting require the -m
flag, too.
PR: bin/60809
Submitted by: Alexander Melkov <melkov@comptek.ru>
Rationale:
SIGURG is configured by ftpd to interrupt system calls, which is useful
during data transfers. However, SIGURG could interrupt I/O on the
control channel as well, which was mistaken for the end of the session.
A practical example could be aborting the download of a tiny file,
when the abort sequence reached ftpd after ftpd had passed the file
data to the system and returned to its command loop.
Reported by: ceri
MFC after: 1 week
- always check the return value from getc(3) for EOF;
- if the attempt to read the TELNET command byte has
returned EOF, exit from the loop instead of using
the EOF value as a normal character.
MFC after: 1 week
don't reveal the info in reply to the SYST command.
Get rid of using the "unix" macro at the same time. It was a rather
poor way to check if the system was Unix since there were quite a
few Unix clones out there whose cc didn't define "unix" (e.g.,
NetBSD.) It was also sensitive to the C standard used, which caused
unnecessary trouble: With -std=c99, it should have been "__unix__",
and so on.
PR: bin/50690
Submitted by: Alex Semenyaka <alexs _at_ snark.ratmir.ru>
MFC after: 1 week
This makes such natural commands as "MKD ~user/newdir" or "STOR ~/newfile"
do what they are supposed to instead of failing miserably with the
"File not found" error.
This involves a bit of code reorganization. Namely, the code doing
glob(3) expansion has been separated to a function; a new function
has been introduced to do tilde expansion; the latter function is
invoked on a pathname before the former one. Thus behaviour mimicing
that of the Bourne shell has been achieved.
if allowed by their filesystem permissions.
This doesn't break anything since using sendfile(2)
is triggered later by a separate S_ISREG conditional.
PR: bin/20824
MFC after: 1 week
separating its part around chroot(2) from that around initial
chdir(2). This makes the below changes really easy.
Move seteuid(to user's uid) to before calling chdir(2). There are
two goals to achieve by that. First, NFS mounted home directories
with restrictive permissions become accessible (local superuser
can't access them if not mapped to uid 0 on the remote side
explicitly.) Second, all the permissions to the home directory
pathname components become effective; previously a user could be
carried to any local directory despite its permissions since the
chdir(2) was done with euid 0. This reduces possible impact from
FTP server misconfiguration, e.g., assigning a wrong home directory
to a user.
Implement the "/./" feature. Now a guest or user subject to chrooting
may have "/./" in his login directory, which separates his chroot
directory from his home directory inside the chrooted environment.
This works for ftpchroot(5) as well.
PR: bin/17843 bin/23944
directory can be specified for a user or a group.
Add the manpage ftpchroot(5) since the file's format has grown
complex enough.
PR: bin/45327
Portions submitted by: Hideki SAKAMOTO <sakamoto@hlla.is.tsukuba.ac.jp>
MFC after: 1 week
to listen at in daemon mode.
- Use the port by 1 less than the control port as the default
data port instead of always using hard-coded port 20.
Submitted by: roam
MFC after: 1 week
to a pathname that contains '\r' or '\n'.
Together with the earlier STAT bugfix, this must solve
the problem of such pathnames appearing in the FTP control
stream.
up port 20 for an extended period of time and thus lock out all other
users from establishing PORT data connections. Don't hold on to the
bind() while we loop around waiting to see if we can make our
connection.
Being a DoS, it has security implications, giving it a short MFC
time.
MFC after: 1 day
