thodg/got/lib/got_lib_privsep.h

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• Hash : 0e4002ca
  Author :
  Date : 2020-03-21T21:49:13
  

  add support for fetching arbitrary references to 'got clone' and 'got fetch'

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• lib/got_lib_privsep.h

• /*
   * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
   * Copyright (c) 2019, Ori Bernstein <ori@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_PROG_READ_GITCONFIG	got-read-gitconfig
  #define GOT_PROG_FETCH_PACK	got-fetch-pack
  #define GOT_PROG_INDEX_PACK	got-index-pack
  #define GOT_PROG_SEND_PACK	got-send-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)
  #define GOT_PATH_PROG_READ_GITCONFIG \
  	GOT_STRINGVAL(GOT_LIBEXECDIR) "/" GOT_STRINGVAL(GOT_PROG_READ_GITCONFIG)
  #define GOT_PATH_PROG_FETCH_PACK \
  	GOT_STRINGVAL(GOT_LIBEXECDIR) "/" GOT_STRINGVAL(GOT_PROG_FETCH_PACK)
  #define GOT_PATH_PROG_SEND_PACK \
  	GOT_STRINGVAL(GOT_LIBEXECDIR) "/" GOT_STRINGVAL(GOT_PROG_SEND_PACK)
  #define GOT_PATH_PROG_INDEX_PACK \
  	GOT_STRINGVAL(GOT_LIBEXECDIR) "/" GOT_STRINGVAL(GOT_PROG_INDEX_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 networking. */
  	GOT_IMSG_FETCH_REQUEST,
  	GOT_IMSG_FETCH_HAVE_REF,
  	GOT_IMSG_FETCH_WANTED_BRANCH,
  	GOT_IMSG_FETCH_WANTED_REF,
  	GOT_IMSG_FETCH_OUTFD,
  	GOT_IMSG_FETCH_SYMREFS,
  	GOT_IMSG_FETCH_REF,
  	GOT_IMSG_FETCH_SERVER_PROGRESS,
  	GOT_IMSG_FETCH_DOWNLOAD_PROGRESS,
  	GOT_IMSG_FETCH_DONE,
  	GOT_IMSG_IDXPACK_REQUEST,
  	GOT_IMSG_IDXPACK_OUTFD,
  	GOT_IMSG_IDXPACK_PROGRESS,
  	GOT_IMSG_IDXPACK_DONE,
  
  	/* Messages related to pack files. */
  	GOT_IMSG_PACKIDX,
  	GOT_IMSG_PACK,
  	GOT_IMSG_PACKED_OBJECT_REQUEST,
  	GOT_IMSG_COMMIT_TRAVERSAL_REQUEST,
  	GOT_IMSG_TRAVERSED_COMMITS,
  	GOT_IMSG_COMMIT_TRAVERSAL_DONE,
  
  	/* Message sending file descriptor to a temporary file. */
  	GOT_IMSG_TMPFD,
  
  	/* Messages related to gitconfig files. */
  	GOT_IMSG_GITCONFIG_PARSE_REQUEST,
  	GOT_IMSG_GITCONFIG_REPOSITORY_FORMAT_VERSION_REQUEST,
  	GOT_IMSG_GITCONFIG_AUTHOR_NAME_REQUEST,
  	GOT_IMSG_GITCONFIG_AUTHOR_EMAIL_REQUEST,
  	GOT_IMSG_GITCONFIG_REMOTES_REQUEST,
  	GOT_IMSG_GITCONFIG_INT_VAL,
  	GOT_IMSG_GITCONFIG_STR_VAL,
  	GOT_IMSG_GITCONFIG_REMOTES,
  	GOT_IMSG_GITCONFIG_REMOTE,
  	GOT_IMSG_GITCONFIG_OWNER_REQUEST,
  	GOT_IMSG_GITCONFIG_OWNER,
  };
  
  /* 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_FETCH_HAVE_REF data. */
  struct got_imsg_fetch_have_ref {
  	uint8_t id[SHA1_DIGEST_LENGTH];
  	size_t name_len;
  	/* Followed by name_len data bytes. */
  } __attribute__((__packed__));
  
  /* Structure for GOT_IMSG_FETCH_WANTED_BRANCH data. */
  struct got_imsg_fetch_wanted_branch {
  	size_t name_len;
  	/* Followed by name_len data bytes. */
  } __attribute__((__packed__));
  
  /* Structure for GOT_IMSG_FETCH_WANTED_REF data. */
  struct got_imsg_fetch_wanted_ref {
  	size_t name_len;
  	/* Followed by name_len data bytes. */
  } __attribute__((__packed__));
  
  /* Structure for GOT_IMSG_FETCH_REQUEST data. */
  struct got_imsg_fetch_request {
  	int fetch_all_branches;
  	int list_refs_only;
  	int verbosity;
  	size_t n_have_refs;
  	size_t n_wanted_branches;
  	size_t n_wanted_refs;
  	/* Followed by n_have_refs GOT_IMSG_FETCH_HAVE_REF messages. */
  	/* Followed by n_wanted_branches times GOT_IMSG_FETCH_WANTED_BRANCH. */
  	/* Followed by n_wanted_refs times GOT_IMSG_FETCH_WANTED_REF. */
  } __attribute__((__packed__));
  
  /* Structures for GOT_IMSG_FETCH_SYMREFS data. */
  struct got_imsg_fetch_symref {
  	size_t name_len;
  	size_t target_len;
  
  	/*
  	 * Followed by name_len + target_len data bytes.
  	 */
  } __attribute__((__packed__));
  
  struct got_imsg_fetch_symrefs {
  	size_t nsymrefs;
  
  	/* Followed by nsymrefs times of got_imsg_fetch_symref data. */
  } __attribute__((__packed__));
  
  /* Structure for GOT_IMSG_FETCH_REF data. */
  struct got_imsg_fetch_ref {
  	/* Describes a reference which will be fetched. */
  	uint8_t refid[SHA1_DIGEST_LENGTH];
  	/* Followed by reference name in remaining data of imsg buffer. */
  };
  
  /* Structure for GOT_IMSG_FETCH_DOWNLOAD_PROGRESS data. */
  struct got_imsg_fetch_download_progress {
  	/* Number of packfile data bytes downloaded so far. */
  	off_t packfile_bytes;
  };
  
  /* Structure for GOT_IMSG_IDXPACK_REQUEST data. */
  struct got_imsg_index_pack_request {
  	uint8_t pack_hash[SHA1_DIGEST_LENGTH];
  } __attribute__((__packed__));
  
  /* Structure for GOT_IMSG_IDXPACK_PROGRESS data. */
  struct got_imsg_index_pack_progress {
  	/* Total number of objects in pack file. */
  	int nobj_total;
  
  	/* Number of objects indexed so far. */
  	int nobj_indexed;
  
  	/* Number of non-deltified objects in pack file. */
  	int nobj_loose;
  
  	/* Number of deltified objects resolved so far. */
  	int nobj_resolved;
  };
  
  /* 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__));
  
  /* Structure for GOT_IMSG_COMMIT_TRAVERSAL_REQUEST  */
  struct got_imsg_commit_traversal_request {
  	uint8_t id[SHA1_DIGEST_LENGTH];
  	int idx;
  	size_t path_len;
  	/* Followed by path_len bytes of path data */
  } __attribute__((__packed__));
  
  /* Structure for GOT_IMSG_TRAVERSED_COMMITS  */
  struct got_imsg_traversed_commits {
  	size_t ncommits;
  	/* Followed by ncommit IDs of SHA1_DIGEST_LENGTH each */
  } __attribute__((__packed__));
  
  /*
   * Structure for GOT_IMSG_GITCONFIG_REMOTE data.
   */
  struct got_imsg_remote {
  	size_t name_len;
  	size_t url_len;
  	int mirror_references;
  
  	/* Followed by name_len + url_len data bytes. */
  } __attribute__((__packed__));
  
  /*
   * Structure for GOT_IMSG_GITCONFIG_REMOTES data.
   */
  struct got_imsg_remotes {
  	int nremotes; /* This many GOT_IMSG_GITCONFIG_REMOTE messages follow. */
  };
  
  struct got_remote_repo;
  struct got_pack;
  struct got_packidx;
  struct got_pathlist_head;
  
  const struct got_error *got_send_ack(pid_t);
  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_ack(struct imsgbuf *);
  const struct got_error *got_privsep_wait_ack(struct imsgbuf *);
  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_send_index_pack_req(struct imsgbuf *,
      uint8_t *, int);
  const struct got_error *got_privsep_send_index_pack_outfd(struct imsgbuf *,
      int);
  const struct got_error *got_privsep_send_index_pack_progress(struct imsgbuf *,
      int, int, int, int);
  const struct got_error *got_privsep_send_index_pack_done(struct imsgbuf *);
  const struct got_error *got_privsep_recv_index_progress(int *, int *, int *,
      int *, int *, struct imsgbuf *ibuf);
  const struct got_error *got_privsep_send_fetch_req(struct imsgbuf *, int,
      struct got_pathlist_head *, int, struct got_pathlist_head *,
      struct got_pathlist_head *, int, int);
  const struct got_error *got_privsep_send_fetch_outfd(struct imsgbuf *, int);
  const struct got_error *got_privsep_send_fetch_symrefs(struct imsgbuf *,
      struct got_pathlist_head *);
  const struct got_error *got_privsep_send_fetch_ref(struct imsgbuf *,
      struct got_object_id *, const char *);
  const struct got_error *got_privsep_send_fetch_server_progress(struct imsgbuf *,
      const char *, size_t);
  const struct got_error *got_privsep_send_fetch_download_progress(struct imsgbuf *,
      off_t);
  const struct got_error *got_privsep_recv_fetch_progress(int *,
      struct got_object_id **, char **, struct got_pathlist_head *,
      char **, off_t *, struct imsgbuf *);
  const struct got_error *got_privsep_send_fetch_done(struct imsgbuf *,
      struct got_object_id);
  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_pathlist_head *, int);
  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 *);
  
  const struct got_error *got_privsep_send_gitconfig_parse_req(struct imsgbuf *,
      int);
  const struct got_error *
      got_privsep_send_gitconfig_repository_format_version_req(struct imsgbuf *);
  const struct got_error *got_privsep_send_gitconfig_author_name_req(
      struct imsgbuf *);
  const struct got_error *got_privsep_send_gitconfig_author_email_req(
      struct imsgbuf *);
  const struct got_error *got_privsep_send_gitconfig_remotes_req(
      struct imsgbuf *);
  const struct got_error *got_privsep_send_gitconfig_owner_req(struct imsgbuf *);
  const struct got_error *got_privsep_send_gitconfig_str(struct imsgbuf *,
      const char *);
  const struct got_error *got_privsep_recv_gitconfig_str(char **,
      struct imsgbuf *);
  const struct got_error *got_privsep_send_gitconfig_int(struct imsgbuf *, int);
  const struct got_error *got_privsep_recv_gitconfig_int(int *, struct imsgbuf *);
  const struct got_error *got_privsep_send_gitconfig_remotes(struct imsgbuf *,
      struct got_remote_repo *, int);
  const struct got_error *got_privsep_recv_gitconfig_remotes(
      struct got_remote_repo **, int *, struct imsgbuf *);
  
  const struct got_error *got_privsep_send_commit_traversal_request(
      struct imsgbuf *, struct got_object_id *, int, const char *);
  const struct got_error *got_privsep_recv_traversed_commits(
      struct got_commit_object **, struct got_object_id **,
      struct got_object_id_queue *, struct imsgbuf *);
  const struct got_error *got_privsep_send_traversed_commits(
      struct got_object_id *, size_t, struct imsgbuf *);
  const struct got_error *got_privsep_send_commit_traversal_done(
      struct imsgbuf *);
  
  void got_privsep_exec_child(int[2], const char *, const char *);
  

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