op public repos

Blame

Date:: Sun Oct 23 00:37:19 2022 UTC
Message:: introduce gotd(8), a Git repository server reachable via ssh(1) This is an initial barebones implementation which provides the absolute minimum of functionality required to serve got(1) and git(1) clients. Basic fetch/send functionality has been tested and seems to work here, but this server is not yet expected to be stable. More testing is welcome. See the man pages for setup instructions. The current design uses one reader and one writer process per repository, which will have to be extended to N readers and N writers in the future. At startup, each process will chroot(2) into its assigned repository. This works because gotd(8) can only be started as root, and will then fork+exec, chroot, and privdrop. At present the parent process runs with the following pledge(2) promises: "stdio rpath wpath cpath proc getpw sendfd recvfd fattr flock unix unveil" The parent is the only process able to modify the repository in a way that becomes visible to Git clients. The parent uses unveil(2) to restrict its view of the filesystem to /tmp and the repositories listed in the configuration file gotd.conf(5). Per-repository chroot(2) processes use "stdio rpath sendfd recvfd". The writer defers to the parent for modifying references in the repository to point at newly uploaded commits. The reader is fine without such help, because Git repositories can be read without having to create any lock-files. gotd(8) requires a dedicated user ID, which should own repositories on the filesystem, and a separate secondary group, which should not have filesystem-level repository access, and must be allowed access to the gotd(8) socket. To obtain Git repository access, users must be members of this secondary group, and must have their login shell set to gotsh(1). gotsh(1) connects to the gotd(8) socket and speaks Git-protocol towards the client on the other end of the SSH connection. gotsh(1) is not an interactive command shell. At present, authenticated clients are granted read/write access to all repositories and all references (except for the "refs/got/" and the "refs/remotes/" namespaces, which are already being protected from modification). While complicated access control mechanism are not a design goal, making it possible to safely offer anonymous Git repository access over ssh(1) is on the road map.
Actions:: History | Blob | Raw File

  1 13b2bc37 2022-10-23 stsp /*
  2 13b2bc37 2022-10-23 stsp  * Copyright (c) 2018, 2022 Stefan Sperling <stsp@openbsd.org>
  3 13b2bc37 2022-10-23 stsp  *
  4 13b2bc37 2022-10-23 stsp  * Permission to use, copy, modify, and distribute this software for any
  5 13b2bc37 2022-10-23 stsp  * purpose with or without fee is hereby granted, provided that the above
  6 13b2bc37 2022-10-23 stsp  * copyright notice and this permission notice appear in all copies.
  7 13b2bc37 2022-10-23 stsp  *
  8 13b2bc37 2022-10-23 stsp  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  9 13b2bc37 2022-10-23 stsp  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 10 13b2bc37 2022-10-23 stsp  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 11 13b2bc37 2022-10-23 stsp  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 12 13b2bc37 2022-10-23 stsp  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 13 13b2bc37 2022-10-23 stsp  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 14 13b2bc37 2022-10-23 stsp  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 15 13b2bc37 2022-10-23 stsp  */
 16 13b2bc37 2022-10-23 stsp 
 17 13b2bc37 2022-10-23 stsp #include <errno.h>
 18 13b2bc37 2022-10-23 stsp #include <stdio.h>
 19 13b2bc37 2022-10-23 stsp #include <signal.h>
 20 13b2bc37 2022-10-23 stsp #include <poll.h>
 21 13b2bc37 2022-10-23 stsp #include <time.h>
 22 13b2bc37 2022-10-23 stsp #include <unistd.h>
 23 13b2bc37 2022-10-23 stsp 
 24 13b2bc37 2022-10-23 stsp #include "got_error.h"
 25 13b2bc37 2022-10-23 stsp 
 26 13b2bc37 2022-10-23 stsp #include "got_lib_poll.h"
 27 13b2bc37 2022-10-23 stsp 
 28 13b2bc37 2022-10-23 stsp const struct got_error *
 29 13b2bc37 2022-10-23 stsp got_poll_fd(int fd, int events, int timeout)
 30 13b2bc37 2022-10-23 stsp {
 31 13b2bc37 2022-10-23 stsp 	struct pollfd pfd[1];
 32 13b2bc37 2022-10-23 stsp 	struct timespec ts;
 33 13b2bc37 2022-10-23 stsp 	sigset_t sigset;
 34 13b2bc37 2022-10-23 stsp 	int n;
 35 13b2bc37 2022-10-23 stsp 
 36 13b2bc37 2022-10-23 stsp 	pfd[0].fd = fd;
 37 13b2bc37 2022-10-23 stsp 	pfd[0].events = events;
 38 13b2bc37 2022-10-23 stsp 
 39 13b2bc37 2022-10-23 stsp 	ts.tv_sec = timeout;
 40 13b2bc37 2022-10-23 stsp 	ts.tv_nsec = 0;
 41 13b2bc37 2022-10-23 stsp 
 42 13b2bc37 2022-10-23 stsp 	if (sigemptyset(&sigset) == -1)
 43 13b2bc37 2022-10-23 stsp 		return got_error_from_errno("sigemptyset");
 44 13b2bc37 2022-10-23 stsp 	if (sigaddset(&sigset, SIGWINCH) == -1)
 45 13b2bc37 2022-10-23 stsp 		return got_error_from_errno("sigaddset");
 46 13b2bc37 2022-10-23 stsp 
 47 13b2bc37 2022-10-23 stsp 	n = ppoll(pfd, 1, timeout == INFTIM ? NULL : &ts, &sigset);
 48 13b2bc37 2022-10-23 stsp 	if (n == -1)
 49 13b2bc37 2022-10-23 stsp 		return got_error_from_errno("ppoll");
 50 13b2bc37 2022-10-23 stsp 	if (n == 0) {
 51 13b2bc37 2022-10-23 stsp 		if (pfd[0].revents & POLLHUP)
 52 13b2bc37 2022-10-23 stsp 			return got_error(GOT_ERR_EOF);
 53 13b2bc37 2022-10-23 stsp 		return got_error(GOT_ERR_TIMEOUT);
 54 13b2bc37 2022-10-23 stsp 	}
 55 13b2bc37 2022-10-23 stsp 	if (pfd[0].revents & (POLLERR | POLLNVAL))
 56 13b2bc37 2022-10-23 stsp 		return got_error_from_errno("poll error");
 57 13b2bc37 2022-10-23 stsp 	if (pfd[0].revents & events)
 58 13b2bc37 2022-10-23 stsp 		return NULL;
 59 13b2bc37 2022-10-23 stsp 	if (pfd[0].revents & POLLHUP)
 60 13b2bc37 2022-10-23 stsp 		return got_error(GOT_ERR_EOF);
 61 13b2bc37 2022-10-23 stsp 
 62 13b2bc37 2022-10-23 stsp 	return got_error(GOT_ERR_INTERRUPT);
 63 13b2bc37 2022-10-23 stsp }
 64 13b2bc37 2022-10-23 stsp 
 65 13b2bc37 2022-10-23 stsp const struct got_error *
 66 13b2bc37 2022-10-23 stsp got_poll_read_full(int fd, size_t *len, void *buf, size_t bufsize,
 67 13b2bc37 2022-10-23 stsp     size_t minbytes)
 68 13b2bc37 2022-10-23 stsp {
 69 13b2bc37 2022-10-23 stsp 	const struct got_error *err = NULL;
 70 13b2bc37 2022-10-23 stsp 	size_t have = 0;
 71 13b2bc37 2022-10-23 stsp 	ssize_t r;
 72 13b2bc37 2022-10-23 stsp 
 73 13b2bc37 2022-10-23 stsp 	if (minbytes > bufsize)
 74 13b2bc37 2022-10-23 stsp 		return got_error(GOT_ERR_NO_SPACE);
 75 13b2bc37 2022-10-23 stsp 
 76 13b2bc37 2022-10-23 stsp 	while (have < minbytes) {
 77 13b2bc37 2022-10-23 stsp 		err = got_poll_fd(fd, POLLIN, INFTIM);
 78 13b2bc37 2022-10-23 stsp 		if (err)
 79 13b2bc37 2022-10-23 stsp 			return err;
 80 13b2bc37 2022-10-23 stsp 		r = read(fd, buf + have, bufsize - have);
 81 13b2bc37 2022-10-23 stsp 		if (r == -1)
 82 13b2bc37 2022-10-23 stsp 			return got_error_from_errno("read");
 83 13b2bc37 2022-10-23 stsp 		if (r == 0)
 84 13b2bc37 2022-10-23 stsp 			return got_error(GOT_ERR_EOF);
 85 13b2bc37 2022-10-23 stsp 		have += r;
 86 13b2bc37 2022-10-23 stsp 	}
 87 13b2bc37 2022-10-23 stsp 
 88 13b2bc37 2022-10-23 stsp 	*len = have;
 89 13b2bc37 2022-10-23 stsp 	return NULL;
 90 13b2bc37 2022-10-23 stsp }
 91 13b2bc37 2022-10-23 stsp 
 92 13b2bc37 2022-10-23 stsp const struct got_error *
 93 13b2bc37 2022-10-23 stsp got_poll_write_full(int fd, const void *buf, off_t len)
 94 13b2bc37 2022-10-23 stsp {
 95 13b2bc37 2022-10-23 stsp 	const struct got_error *err = NULL;
 96 13b2bc37 2022-10-23 stsp 	off_t wlen = 0;
 97 13b2bc37 2022-10-23 stsp 	ssize_t w = 0;
 98 13b2bc37 2022-10-23 stsp 
 99 13b2bc37 2022-10-23 stsp 	while (wlen != len) {
100 13b2bc37 2022-10-23 stsp 		if (wlen > 0) {
101 13b2bc37 2022-10-23 stsp 			err = got_poll_fd(fd, POLLOUT, INFTIM);
102 13b2bc37 2022-10-23 stsp 			if (err)
103 13b2bc37 2022-10-23 stsp 				return err;
104 13b2bc37 2022-10-23 stsp 		}
105 13b2bc37 2022-10-23 stsp 		w = write(fd, buf + wlen, len - wlen);
106 13b2bc37 2022-10-23 stsp 		if (w == -1) {
107 13b2bc37 2022-10-23 stsp 			if (errno != EAGAIN)
108 13b2bc37 2022-10-23 stsp 				return got_error_from_errno("write");
109 13b2bc37 2022-10-23 stsp 		} else
110 13b2bc37 2022-10-23 stsp 			wlen += w;
111 13b2bc37 2022-10-23 stsp 	}
112 13b2bc37 2022-10-23 stsp 
113 13b2bc37 2022-10-23 stsp 	return NULL;
114 13b2bc37 2022-10-23 stsp }