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.

get rid of unneeded recv_imsg_error calls got_privsep_recv_imsg users don't need to bother to look whether the imsg type is GOT_IMSG_ERROR because got_privsep_recv_imsg already takes care of that and turns GOT_IMSG_ERROR into `struct got_error's automatically. ok stsp@

rework got_privesp_recv_tree to use got_privsep_recv_imsg ok stsp@

add signer_id option to got.conf(5) Setting this option will cause 'got tag' to sign all created tags using the SSH key, unless overridden by the -s flag. ok stsp@

create and verify tags signed by SSH keys This adds a new -s flag to 'got tag' that specifies the signer identity (for example, a key file) of the tagger. The tag object will include a signature that validates each of the tag object headers and the tag message. Verifying these signed tags requires maintaining an allowed signers file which maps signer identities (i.e. the email address of the tagger) to SSH public keys. See ssh-keygen(1) for more details of the allowed signers file. After creating this file and providing the path to it in got.conf(5) using the allowed_signers option, tags may be verified using with 'got tag -V tag_name'. The return code will be non-zero if a signature fails to verify. ok stsp@

fix imsg_add TREE_ENTRY: Result too large on i386 There's a math error when computing the size of one entries in the batching code. Reported by semarie, ok semarie stsp

implement support for commit coloring in got-read-pack for speed ok op, tracey

build with -Wmissing-prototypes ok stsp@

fix unexpected imsg error after incomplete enumeration in got-read-pack reported by jrick and op@ ok op@

memset all stack-allocated structs used to send messages; ok stsp@

zero the whole struct got_imsg_object before sending it otherwise some fields may be unitialized and fail the validation done on the receiving side. ok stsp@

fix a harmless off-by-one from previous commit

fix a bug in got_privsep_send_object_idlist() exposed by recent changes The old code did not work correctly if only a single object Id was to be sent to got-read-pack. Make got-read-pack error out if the list of commits for object enumeration is empty to catch this problem if it occurs again. Found by the send_basic test, which was failing with GOT_TEST_PACK=1 ok tracey

let got-read-pack be explicit about whether it could enumerate all objects This allows the main process to avoid looping over all object IDs again in case the pack file used for enumeration is complete. ok op@

remove trailing whitespaces