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
in the output to the "STAT file" request.
This closes one discrepancy with RFC 959 (page 36.)
See also http://www.kb.cert.org/vuls/id/328867
Obtained from: OpenBSD
Properly sort options, spell "file system" correctly, expand contraction.
Catch up to the src/etc/syslog.conf,v 1.23 change: ftpd(8) session logs
are now by default get logged to /var/log/xferlog.
Approved by: re
memory area would arise. Only an addrinfo list from an earlier
call to getaddrinfo() should be freed there because it will be
substituted by the current list referenced by "res".
Reported by: John Long <fbsd1@pruam.com>
MFC after: 5 days
MAC labels are set if MAC is enabled and configured for the user
logging in.
Note that lukemftpd is not considered a supported application when
MAC is enabled, as it does not use the standard system interfaces for
managing user contexts; if lukemftpd is used with labeled MAC policies,
it will not properly give up privileges when switching to the user
account.
Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
than the LOMAC-specific interfaces for listing MAC labels. This permits
ls to view MAC labels in a manner similar to getfmac, when ls is used
with the -l argument. Next generation LOMAC will use the MAC Framework
so should "just" work with this and other policies. Not the prettiest
code in the world, but then, neither is ls(1).
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
o Don't free(3) memory occupied by host structures
already in the host list.
o Set hrp->hostinfo to NULL if a host record has to stay in
the host list, but is to be ignored. Selecthost() knows that.
o Reduce the pollution with excessive NULL checks.
o Close a couple of memory leaks.
MFC after: 1 week
o check getaddrinfo(3) return value, not result pointer
o getaddrinfo(3) returns int, not pointer
o don't leak memory allocated for hostnames and hostinfo structures
o initialize pointers that will be checked for NULL somewhere
MFC after: 1 week
o Remove the race between stat(2) & fopen(3) when creating
a unique file.
o Improve bound checking when generating a unique name from
a given pathname.
o Ignore REST marker on APPE. No RFC specifies this case,
but the idea of resuming APPE's implies this.
o By default, deny upload resumes and appends by anonymous users.
Previously these commands were translated to STOU silently,
which led to broken files on server without any notification
to the user.
o Add an option, -m, to allow anonymous users to modify
existing files (e.g., to resume uploads) if filesystem
permissions permit.
Portions obrainded from: OpenBSD
MFC after: 3 weeks
Earlier, a decimal number (e.g., 890) could be passed
for mode, leading to dangerous permissions set:
-1, that is, 07777.
Obtained from: OpenBSD
MFC after: 1 week
socket option to avoid exausting the passive port
space by TIME_WAIT'ing connections.
PR: bin/36955
Submitted by: Maxim Konovalov <maxim@FreeBSD.org>
MFC after: 2 weeks
write(2), and getipnodebyaddr(3) calls. Now all the above functions
accept "void *" in that arguments and have prototypes. Thus, the
casts are useless under the normal circumstances (and would be harmful
if the functions had no prototypes.)
MFC after: 2 weeks
o Always check a setsockopt(2) return value
o Use a consistent message format
o Don't abort if the failed setsockopt(2) was actually not vital
o Use LOG_WARNING, not LOG_ERR, in non-fatal cases
MFC after: 1 week
o "struct addrinfo" contains a pointer to "struct sockaddr,"
not "struct sockaddr" itself
o the function takes a pointer to "struct in*_addr", not to
"struct sockaddr," so the address length must be corresponding
MFC after: 1 week
Thus lines of any length can be handled, unlike before.
Don't assume that each line read from the files ends with a newline.
As a side effect in inithosts(), don't use automatic buffer at all,
utilize malloc(3) when getting local host name instead.
PR: misc/21494
Reviewed by: maxim, mikeh
MFC after: 1 month
