/*
* Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* All code runs under the same UID but sensitive code paths are
* run in a separate process with tighter pledge(2) promises.
* Data is communicated between processes via imsg_flush(3) and imsg_read(3).
* This behaviour is transparent to users of the library.
*
* We generally transmit data in imsg buffers, split across several messages
* if necessary. File descriptor passing is used in cases where this is
* impractical, such as when accessing pack files or when transferring
* large blobs.
*
* We currently do not exec(2) after a fork(2).
* To achieve fork+exec, relevant parts of our library functionality could
* be made accessible via separate executables in a libexec directory.
*/
enum got_imsg_type {
/* An error occured while processing a request. */
GOT_IMSG_ERROR,
/* Messages for transmitting deltas and associated delta streams. */
GOT_IMSG_DELTA,
GOT_IMSG_DELTA_STREAM,
/*
* Messages concerned with read access to objects in a repository.
* Object and pack files are opened by the main process, where
* data may be read as a byte string but without any interpretation.
* Decompression and parsing of object and pack files occurs in a
* separate process which runs under pledge("stdio").
* This sandboxes our own repository parsing code, as well as zlib.
*/
GOT_IMSG_OBJECT,
GOT_IMSG_COMMIT,
GOT_IMSG_TREE,
GOT_IMSG_TREE_ENTRY,
GOT_IMSG_BLOB,
};
/* Structure for GOT_IMSG_ERROR. */
struct got_imsg_error {
int code; /* an error code from got_error.h */
int errno_code; /* in case code equals GOT_ERR_ERRNO */
};
/* Structure for GOT_IMSG_DELTA data. */
struct got_imsg_delta {
/* These fields are the same as in struct got_delta. */
off_t offset;
size_t tslen;
int type;
size_t size;
off_t data_offset;
size_t delta_len;
/*
* Followed by delta stream in remaining bytes of imsg buffer.
* If delta_len exceeds imsg buffer length, followed by one or
* more DELTA_STREAM messages until delta_len bytes of delta
* stream have been transmitted.
*/
};
/* Structure for GOT_IMSG_DELTA_STREAM data. */
struct got_imsg_delta_stream {
/*
* Empty since the following is implied:
* Read additional delta stream data from imsg buffer.
*/
};
/* Structure for GOT_IMSG_OBJECT data. */
struct got_imsg_object {
/* These fields are the same as in struct got_object. */
int type;
int flags;
size_t hdrlen;
size_t size;
int ndeltas; /* this many GOT_IMSG_DELTA messages follow */
};
/* Structure for GOT_IMSG_COMMIT data. */
struct got_imsg_commit_object {
uint8_t tree_id[SHA1_DIGEST_LENGTH];
size_t author_len;
size_t committer_len;
size_t logmsg_len;
int nparents;
/* Followed by author_len + committer_len + logmsg_len data bytes */
/* Followed by 'nparents' SHA1_DIGEST_LENGTH length strings */
/* XXX should use more messages to support very large log messages */
} __attribute__((__packed__));
/* Structure for GOT_IMSG_TREE_ENTRY. */
struct got_imsg_tree_entry {
char id[SHA1_DIGEST_LENGTH];
mode_t mode;
/* Followed by entry's name in remaining data of imsg buffer. */
} __attribute__((__packed__));
/* Structure for GOT_IMSG_TREE_OBJECT_REPLY data. */
struct got_imsg_tree_object {
int nentries; /* This many TREE_ENTRY messages follow. */
};
void got_privsep_send_error(struct imsgbuf *, const struct got_error *);
const struct got_error *got_privsep_send_obj(struct imsgbuf *,
struct got_object *, int);
const struct got_error *got_privsep_recv_obj(struct got_object **,
struct imsgbuf *);
const struct got_error *got_privsep_send_commit_obj(struct imsgbuf *,
struct got_commit_object *);
const struct got_error *got_privsep_recv_commit_obj(struct got_commit_object **,
struct imsgbuf *);
const struct got_error *got_privsep_recv_tree_obj(struct got_tree_object **,
struct imsgbuf *);
const struct got_error *got_privsep_send_tree_obj(struct imsgbuf *,
struct got_tree_object *);
/* TODO: Implement the above, and then add more message data types here. */
