/*
* Copyright (c) 2018, 2019 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 descriptors are used in cases where this is impractical,
* such as when accessing pack files or when transferring large blobs.
*
* We exec(2) after a fork(2). Parts of our library functionality are
* accessible via separate executables in a libexec directory.
*/
#define GOT_IMSG_FD_CHILD (STDERR_FILENO + 1)
#ifndef GOT_LIBEXECDIR
#define GOT_LIBEXECDIR /usr/libexec
#endif
/* Names of helper programs in libexec directory */
#define GOT_PROG_READ_OBJECT got-read-object
#define GOT_PROG_READ_TREE got-read-tree
#define GOT_PROG_READ_COMMIT got-read-commit
#define GOT_PROG_READ_BLOB got-read-blob
#define GOT_PROG_READ_TAG got-read-tag
#define GOT_PROG_READ_PACK got-read-pack
#define GOT_STRINGIFY(x) #x
#define GOT_STRINGVAL(x) GOT_STRINGIFY(x)
/* Paths to helper programs in libexec directory */
#define GOT_PATH_PROG_READ_OBJECT \
GOT_STRINGVAL(GOT_LIBEXECDIR) "/" GOT_STRINGVAL(GOT_PROG_READ_OBJECT)
#define GOT_PATH_PROG_READ_TREE \
GOT_STRINGVAL(GOT_LIBEXECDIR) "/" GOT_STRINGVAL(GOT_PROG_READ_TREE)
#define GOT_PATH_PROG_READ_COMMIT \
GOT_STRINGVAL(GOT_LIBEXECDIR) "/" GOT_STRINGVAL(GOT_PROG_READ_COMMIT)
#define GOT_PATH_PROG_READ_BLOB \
GOT_STRINGVAL(GOT_LIBEXECDIR) "/" GOT_STRINGVAL(GOT_PROG_READ_BLOB)
#define GOT_PATH_PROG_READ_TAG \
GOT_STRINGVAL(GOT_LIBEXECDIR) "/" GOT_STRINGVAL(GOT_PROG_READ_TAG)
#define GOT_PATH_PROG_READ_PACK \
GOT_STRINGVAL(GOT_LIBEXECDIR) "/" GOT_STRINGVAL(GOT_PROG_READ_PACK)
struct got_privsep_child {
int imsg_fd;
pid_t pid;
struct imsgbuf *ibuf;
};
enum got_imsg_type {
/* An error occured while processing a request. */
GOT_IMSG_ERROR,
/* Stop the child process. */
GOT_IMSG_STOP,
/*
* 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 recvfd").
* This sandboxes our own repository parsing code, as well as zlib.
*/
GOT_IMSG_OBJECT_REQUEST,
GOT_IMSG_OBJECT,
GOT_IMSG_COMMIT_REQUEST,
GOT_IMSG_COMMIT,
GOT_IMSG_COMMIT_LOGMSG,
GOT_IMSG_TREE_REQUEST,
GOT_IMSG_TREE,
GOT_IMSG_TREE_ENTRY,
GOT_IMSG_BLOB_REQUEST,
GOT_IMSG_BLOB_OUTFD,
GOT_IMSG_BLOB,
GOT_IMSG_TAG_REQUEST,
GOT_IMSG_TAG,
GOT_IMSG_TAG_TAGMSG,
/* Messages related to pack files. */
GOT_IMSG_PACKIDX,
GOT_IMSG_PACK,
GOT_IMSG_PACKED_OBJECT_REQUEST,
/* Message sending file desciprtor to a temporary file. */
GOT_IMSG_TMPFD,
};
/* 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 */
} __attribute__((__packed__));
/*
* Structure for GOT_IMSG_TREE_REQUEST and GOT_IMSG_OBJECT data.
*/
struct got_imsg_object {
uint8_t id[SHA1_DIGEST_LENGTH];
/* These fields are the same as in struct got_object. */
int type;
int flags;
size_t hdrlen;
size_t size;
off_t pack_offset;
int pack_idx;
} __attribute__((__packed__));
/* Structure for GOT_IMSG_COMMIT data. */
struct got_imsg_commit_object {
uint8_t tree_id[SHA1_DIGEST_LENGTH];
size_t author_len;
time_t author_time;
time_t author_gmtoff;
size_t committer_len;
time_t committer_time;
time_t committer_gmtoff;
size_t logmsg_len;
int nparents;
/*
* Followed by author_len + committer_len data bytes
*/
/* Followed by 'nparents' SHA1_DIGEST_LENGTH length strings */
/*
* Followed by 'logmsg_len' bytes of commit log message data in
* one or more GOT_IMSG_COMMIT_LOGMSG 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. */
};
/* Structure for GOT_IMSG_BLOB. */
struct got_imsg_blob {
size_t size;
size_t hdrlen;
/*
* If size <= GOT_PRIVSEP_INLINE_BLOB_DATA_MAX, blob data follows
* in the imsg buffer. Otherwise, blob data has been written to a
* file descriptor passed via the GOT_IMSG_BLOB_OUTFD imsg.
*/
#define GOT_PRIVSEP_INLINE_BLOB_DATA_MAX \
(MAX_IMSGSIZE - IMSG_HEADER_SIZE - sizeof(struct got_imsg_blob))
};
/* Structure for GOT_IMSG_TAG data. */
struct got_imsg_tag_object {
uint8_t id[SHA1_DIGEST_LENGTH];
int obj_type;
size_t tag_len;
size_t tagger_len;
time_t tagger_time;
time_t tagger_gmtoff;
size_t tagmsg_len;
/*
* Followed by tag_len + tagger_len data bytes
*/
/*
* Followed by 'tagmsg_len' bytes of tag message data in
* one or more GOT_IMSG_TAG_TAGMSG messages.
*/
} __attribute__((__packed__));
/* Structure for GOT_IMSG_PACKIDX. */
struct got_imsg_packidx {
size_t len;
/* Additionally, a file desciptor is passed via imsg. */
};
/* Structure for GOT_IMSG_PACK. */
struct got_imsg_pack {
char path_packfile[PATH_MAX];
size_t filesize;
/* Additionally, a file desciptor is passed via imsg. */
} __attribute__((__packed__));
/*
* Structure for GOT_IMSG_PACKED_OBJECT_REQUEST data.
*/
struct got_imsg_packed_object {
uint8_t id[SHA1_DIGEST_LENGTH];
int idx;
} __attribute__((__packed__));
struct got_pack;
struct got_packidx;
const struct got_error *got_privsep_wait_for_child(pid_t);
const struct got_error *got_privsep_send_stop(int);
const struct got_error *got_privsep_recv_imsg(struct imsg *, struct imsgbuf *,
size_t);
void got_privsep_send_error(struct imsgbuf *, const struct got_error *);
const struct got_error *got_privsep_send_obj_req(struct imsgbuf *, int);
const struct got_error *got_privsep_send_commit_req(struct imsgbuf *, int,
struct got_object_id *, int);
const struct got_error *got_privsep_send_tree_req(struct imsgbuf *, int,
struct got_object_id *, int);
const struct got_error *got_privsep_send_tag_req(struct imsgbuf *, int,
struct got_object_id *, int);
const struct got_error *got_privsep_send_blob_req(struct imsgbuf *, int,
struct got_object_id *, int);
const struct got_error *got_privsep_send_blob_outfd(struct imsgbuf *, int);
const struct got_error *got_privsep_send_tmpfd(struct imsgbuf *, int);
const struct got_error *got_privsep_send_obj(struct imsgbuf *,
struct got_object *);
const struct got_error *got_privsep_get_imsg_obj(struct got_object **,
struct imsg *, struct imsgbuf *);
const struct got_error *got_privsep_recv_obj(struct got_object **,
struct imsgbuf *);
const struct got_error *got_privsep_send_commit(struct imsgbuf *,
struct got_commit_object *);
const struct got_error *got_privsep_recv_commit(struct got_commit_object **,
struct imsgbuf *);
const struct got_error *got_privsep_recv_tree(struct got_tree_object **,
struct imsgbuf *);
const struct got_error *got_privsep_send_tree(struct imsgbuf *,
struct got_tree_object *);
const struct got_error *got_privsep_send_blob(struct imsgbuf *, size_t, size_t,
const uint8_t *);
const struct got_error *got_privsep_recv_blob(uint8_t **, size_t *, size_t *,
struct imsgbuf *);
const struct got_error *got_privsep_send_tag(struct imsgbuf *,
struct got_tag_object *);
const struct got_error *got_privsep_recv_tag(struct got_tag_object **,
struct imsgbuf *);
const struct got_error *got_privsep_init_pack_child(struct imsgbuf *,
struct got_pack *, struct got_packidx *);
const struct got_error *got_privsep_send_packed_obj_req(struct imsgbuf *, int,
struct got_object_id *);
const struct got_error *got_privsep_send_pack_child_ready(struct imsgbuf *);
