Commit Graph

481 Commits

Author SHA1 Message Date
Nicholas J. Kain 58b4ba768c If the IP header length does not match the size of the UDP packet received
via the raw socket, print both lengths in the warning message.
2014-04-15 15:23:52 -04:00
Nicholas J. Kain 730e5ef310 setpgid() can return EPERM if we are already a process group leader. 2014-04-15 15:02:20 -04:00
Nicholas J. Kain e5834da6d3 Permit sendmsg in the seccomp syscall whitelist for all daemons. 2014-04-15 14:57:07 -04:00
Nicholas J. Kain b5f0ccd88d In cfg.rl, when performing clear action, don't clear the cs member in ccfg. 2014-04-15 14:56:35 -04:00
Nicholas J. Kain a777766cc6 Fix stupid typo in ndhc.c that would cause the clientid option to
corrupt the start of the hostname option if both were specified.
2014-04-15 14:55:50 -04:00
Nicholas J. Kain 8a9fbb6f09 Documentation updates. 2014-04-14 18:32:08 -04:00
Nicholas J. Kain 74ad01a086 Update the manual page. 2014-04-14 15:52:39 -04:00
Nicholas J. Kain a501789e04 Parse config options with ragel and support a configuration file. 2014-04-14 15:06:31 -04:00
Nicholas J. Kain 51033d3664 Detect the glibc version in CMake and link librt if it is required.
For the Makefile, unconditionally link librt with no detection.
2014-04-07 19:14:31 -04:00
Nicholas J. Kain d267c2c44b Use the raw capability interface via updated ncmlib rather than linking
to libcap.
2014-04-07 15:05:34 -04:00
Nicholas J. Kain bb1ff7a506 arp.c: Make logging messages print the associated interface name. 2014-04-07 04:43:21 -04:00
Nicholas J. Kain 74678ef510 Use safe_recvmsg(). 2014-04-07 04:22:32 -04:00
Nicholas J. Kain 6804be2277 Use safe_sendto where necessary, and check for short writes.
Also, change many log_lines to log_errors, mostly in ifset.c.
2014-04-07 04:15:02 -04:00
Nicholas J. Kain 650da6a7fd Add recvfrom to the seccomp syscall whitelist. 2014-04-07 03:54:30 -04:00
Nicholas J. Kain cab9162d8d Remove socketpair from the seccomp syscall filter whitelist.
socketpair() is called only before privileges are dropped, so it does
not need to be in the whitelist.
2014-04-07 03:44:53 -04:00
Nicholas J. Kain 5fa2030bab Use a socketpair rather than a pair of pipes for communication between
ndhc and ifch, similar to sockd.  A single pipe is also maintained so
that SIGPIPE can bound the lifetime of an orphaned ifch process.
2014-04-07 03:44:02 -04:00
Nicholas J. Kain e2ee728982 Consolidate all of the global static variables in arp.c into a single
struct, and use booleans where appropriate.
2014-04-06 22:12:31 -04:00
Nicholas J. Kain a86363f248 Create a new process ID group for ndhc. 2014-04-06 22:07:12 -04:00
Nicholas J. Kain b761889025 Move source from ndhc/ to src/ since ifchd is no longer a separate program. 2014-04-06 16:57:06 -04:00
Nicholas J. Kain b511d45c2f Change most error comparisons from == -1 to < 0. Some were not changed,
as the different negative values equate to different errors.

Tests against syscall returns and fds are very common and mostly fit
the pattern of this change.

The gain is increased range-exclusion.
2014-04-06 06:33:14 -04:00
Nicholas J. Kain c03be059f5 writeordie() was buggy; delete the == 1 which makes no sense. 2014-04-06 06:31:40 -04:00
Nicholas J. Kain 3d76fbeedc Make sure that all safe_* return values use ssize_t. 2014-04-06 06:24:13 -04:00
Nicholas J. Kain 745e9e8923 If we encounter read errors reading the duid or iaid after successfully
opening the file, print an error and exit.
2014-04-06 06:06:53 -04:00
Nicholas J. Kain 7b0db5b8d3 arp.c: If the safe_read that fetches arp responses encounters a
return of -1 with errno == EAGAIN or EWOULDBLOCK, then report the
error, as it should never happen given that the function is called
only once after polling for ready-reads.

Further, the old code was buggy; it would subtract from the arpreply_offset
the return value of -1 in that case, which is just wrong.
2014-04-06 06:02:03 -04:00
Nicholas J. Kain 8b4c7f05b2 arp.c: Check for < 0 for invalid fds and function errors instead of == -1. 2014-04-06 05:54:21 -04:00
Nicholas J. Kain 8af6bee46d arp_switch_state() was far too confusing and buggy. Pass the target state as
an argument, and only switch the global state after a change is successfully
made.
2014-04-06 05:51:52 -04:00
Nicholas J. Kain 1e52914f2e Remove a lot of permitted syscalls from the seccomp filter list.
Probably the most notable is that setsockopt is only allowed from sockd.
This change prevents ndhc and ifch from removing BPF filters that have been
installed onto a socket.
2014-04-06 05:21:56 -04:00
Nicholas J. Kain 812912126e ifch doesn't need to save a pidfile because its lifetime is strictly bounded
by that of ndhc by the shared pipe, so remove that option.
2014-04-06 02:27:52 -04:00
Nicholas J. Kain 6b1d422d6f arp_min_close_fd() and arp_close_fd() can return void. 2014-04-05 23:40:18 -04:00
Nicholas J. Kain 1c30247c36 arp_reopen_fd() can be return void. 2014-04-05 23:37:44 -04:00
Nicholas J. Kain 6750209e12 Have sockd apply BPF filters to ARP sockets. 2014-04-05 21:39:27 -04:00
Nicholas J. Kain 5212e0dfc5 Switch to using a socket for ndhc/sockd IPC so that fd passing works. 2014-04-05 05:25:56 -04:00
Nicholas J. Kain 9622640698 Add command line help for the sockd-user option. 2014-04-05 05:23:37 -04:00
Nicholas J. Kain ef51971a6d Update to latest ncmlib privilege.[ch]. 2014-04-05 05:23:18 -04:00
Nicholas J. Kain 09d6f7dfb8 Introduce a ndhc-sockd daemon that separates out the remaining elevated
capabilities from the ndhc master process.

Privsep is now complete.  The only notable improvement from before is that
exploitation of ndhc would only allow an attacker to open raw sockets,
bind sockets to ports < port 1024, and create broadcast sockets on the
interface that ndhc is performing dhcp on rather than on all interfaces.

However, this seems like a worthwhile change; note that it was already
impossible for an attacker to sniff packets on any interfaces (as that
requires CAP_NET_ADMIN, which was always separated to ifch).
2014-04-04 04:12:25 -04:00
Nicholas J. Kain 65c3cd4fd9 Make many more logging prints specify the interface and function, and make
the return checks for safe_(read|write) stricter.
2014-04-04 04:01:49 -04:00
Nicholas J. Kain 2200b68aff Print a warning if the BPF is not installed for an ARP socket. 2014-04-04 03:55:32 -04:00
Nicholas J. Kain dc2ac46fd4 Update to latest ncmlib and remove some dead preprocessor defines. 2014-03-31 16:06:41 -04:00
Nicholas J. Kain 2f54ff75f3 Use nk_uidgidbyname(). 2014-03-30 22:18:04 -04:00
Nicholas J. Kain 2d8654ae59 Update copyright dates. 2014-03-30 17:23:35 -04:00
Nicholas J. Kain 1abf8462d3 Convert logging messages to suicide() where appropriate and clean up the
logging messages a bit.
2014-03-30 17:21:27 -04:00
Nicholas J. Kain 82d9682ed8 Update to latest ncmlib changes. 2014-03-30 17:02:48 -04:00
Nicholas J. Kain abda60e0e9 Remove unused defines. 2014-03-28 11:17:52 -04:00
Nicholas J. Kain 1b6b52d2eb Don't background the daemon by default. Process supervision is finally
catching on and becoming the norm.
2014-03-28 00:12:33 -04:00
Nicholas J. Kain 704e414171 Add nl_sendgetaddr and nl_sendgetaddrs variants for v4/v6. 2014-03-28 00:09:53 -04:00
Nicholas J. Kain 77ce7b9a6c printf 'hh' length modifier is a gnu extension. Don't use it. 2014-03-25 05:27:47 -04:00
Nicholas J. Kain 00e7e2a61b Remove an implicit narrowing cast from void* in nl.h.
This cast is fine in C, but if the header is included from C++, even from
an extern "C" block, it will cause an error.
2014-03-24 09:55:55 -04:00
Nicholas J. Kain 4b92b10f32 ifch doesn't need chmod or unlink whitelisted for seccomp-filter. 2014-03-22 23:39:50 -04:00
Nicholas J. Kain 71db577ed5 Replace the remaining calls to rand() with nk_random_u32(). 2014-03-22 02:08:23 -04:00
Nicholas J. Kain 009f80b428 x86 has a slightly different syscall interface, so some changes are
necessary for the seccomp filters to work.

Specifically, x86 has the old catch-all socketcall and the non-legacy
fnctl64 system calls.
2014-03-22 01:32:55 -04:00