/*
* 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.
*/
#include <sys/types.h>
#include <sys/queue.h>
#include <dirent.h>
#include <sha1.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <util.h>
#include <zlib.h>
#include <time.h>
#include "got_error.h"
#include "got_object.h"
#include "got_repository.h"
#include "got_reference.h"
#include "got_lib_sha1.h"
#include "got_lib_path.h"
#include "got_lib_delta.h"
#include "got_lib_inflate.h"
#include "got_lib_object.h"
#ifndef nitems
#define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
#endif
#define GOT_REF_HEADS "heads"
#define GOT_REF_TAGS "tags"
#define GOT_REF_REMOTES "remotes"
/* A symbolic reference. */
struct got_symref {
char *name;
char *ref;
};
/* A non-symbolic reference (there is no better designation). */
struct got_ref {
char *name;
u_int8_t sha1[SHA1_DIGEST_LENGTH];
};
/* A reference which points to an arbitrary object. */
struct got_reference {
unsigned int flags;
#define GOT_REF_IS_SYMBOLIC 0x01
union {
struct got_ref ref;
struct got_symref symref;
} ref;
};
static const struct got_error *
parse_symref(struct got_reference **ref, const char *name, const char *line)
{
struct got_symref *symref;
char *symref_name;
char *symref_ref;
if (line[0] == '\0')
return got_error(GOT_ERR_BAD_REF_DATA);
symref_name = strdup(name);
if (symref_name == NULL)
return got_error_from_errno();
symref_ref = strdup(line);
if (symref_ref == NULL) {
const struct got_error *err = got_error_from_errno();
free(symref_name);
return err;
}
*ref = calloc(1, sizeof(**ref));
if (*ref == NULL)
return got_error_from_errno();
(*ref)->flags |= GOT_REF_IS_SYMBOLIC;
symref = &((*ref)->ref.symref);
symref->name = symref_name;
symref->ref = symref_ref;
return NULL;
}
static const struct got_error *
parse_ref_line(struct got_reference **ref, const char *name, const char *line)
{
uint8_t digest[SHA1_DIGEST_LENGTH];
char *ref_name;
if (strncmp(line, "ref: ", 5) == 0) {
line += 5;
return parse_symref(ref, name, line);
}
ref_name = strdup(name);
if (ref_name == NULL)
return got_error_from_errno();
if (!got_parse_sha1_digest(digest, line))
return got_error(GOT_ERR_BAD_REF_DATA);
*ref = calloc(1, sizeof(**ref));
if (*ref == NULL)
return got_error_from_errno();
(*ref)->ref.ref.name = ref_name;
memcpy(&(*ref)->ref.ref.sha1, digest, SHA1_DIGEST_LENGTH);
return NULL;
}
static const struct got_error *
parse_ref_file(struct got_reference **ref, const char *name,
const char *abspath)
{
const struct got_error *err = NULL;
FILE *f = fopen(abspath, "rb");
char *line;
size_t len;
const char delim[3] = {'\0', '\0', '\0'};
if (f == NULL)
return NULL;
line = fparseln(f, &len, NULL, delim, 0);
if (line == NULL) {
err = got_error(GOT_ERR_BAD_REF_DATA);
goto done;
}
err = parse_ref_line(ref, name, line);
done:
free(line);
if (fclose(f) != 0 && err == NULL)
err = got_error_from_errno();
return err;
}
static int
is_well_known_ref(const char *refname)
{
return (strcmp(refname, GOT_REF_HEAD) == 0 ||
strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
strcmp(refname, GOT_REF_FETCH_HEAD) == 0);
}
static char *
get_refs_dir_path(struct got_repository *repo, const char *refname)
{
if (is_well_known_ref(refname) || strncmp(refname, "refs/", 5) == 0)
return strdup(got_repo_get_path_git_dir(repo));
return got_repo_get_path_refs(repo);
}
static const struct got_error *
parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
const char *line)
{
uint8_t digest[SHA1_DIGEST_LENGTH];
char *name;
*ref = NULL;
if (line[0] == '#' || line[0] == '^')
return NULL;
if (!got_parse_sha1_digest(digest, line))
return got_error(GOT_ERR_BAD_REF_DATA);
if (abs_refname) {
if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
return NULL;
name = strdup(abs_refname);
if (name == NULL)
return got_error_from_errno();
} else
name = strdup(line + SHA1_DIGEST_STRING_LENGTH);
*ref = calloc(1, sizeof(**ref));
if (*ref == NULL)
return got_error_from_errno();
(*ref)->ref.ref.name = name;;
memcpy(&(*ref)->ref.ref.sha1, digest, SHA1_DIGEST_LENGTH);
return NULL;
}
static const struct got_error *
open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
int nsubdirs, const char *refname)
{
const struct got_error *err = NULL;
char *abs_refname;
char *line;
size_t len;
const char delim[3] = {'\0', '\0', '\0'};
int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);
*ref = NULL;
if (ref_is_absolute)
abs_refname = (char *)refname;
do {
line = fparseln(f, &len, NULL, delim, 0);
if (line == NULL)
break;
for (i = 0; i < nsubdirs; i++) {
if (!ref_is_absolute &&
asprintf(&abs_refname, "refs/%s/%s", subdirs[i],
refname) == -1)
return got_error_from_errno();
err = parse_packed_ref_line(ref, abs_refname, line);
if (!ref_is_absolute)
free(abs_refname);
if (err || *ref != NULL)
break;
}
free(line);
if (err)
break;
} while (*ref == NULL);
return err;
}
static const struct got_error *
open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
const char *name)
{
const struct got_error *err = NULL;
char *path = NULL;
char *normpath = NULL;
char *absname = NULL;
int ref_is_absolute = (strncmp(name, "refs/", 5) == 0);
int ref_is_well_known = is_well_known_ref(name);
*ref = NULL;
if (ref_is_absolute || ref_is_well_known) {
if (asprintf(&path, "%s/%s", path_refs, name) == -1)
return got_error_from_errno();
absname = (char *)name;
} else {
if (asprintf(&path, "%s/%s/%s", path_refs, subdir, name) == -1)
return got_error_from_errno();
if (asprintf(&absname, "refs/%s/%s", subdir, name) == -1) {
err = got_error_from_errno();
goto done;
}
}
normpath = got_path_normalize(path);
if (normpath == NULL) {
err = got_error_from_errno();
goto done;
}
err = parse_ref_file(ref, absname, normpath);
done:
if (!ref_is_absolute && !ref_is_well_known)
free(absname);
free(path);
free(normpath);
return err;
}
const struct got_error *
got_ref_open(struct got_reference **ref, struct got_repository *repo,
const char *refname)
{
const struct got_error *err = NULL;
char *path_refs = NULL;
const char *subdirs[] = {
GOT_REF_HEADS, GOT_REF_TAGS, GOT_REF_REMOTES
};
int i, well_known = is_well_known_ref(refname);
*ref = NULL;
path_refs = get_refs_dir_path(repo, refname);
if (path_refs == NULL) {
err = got_error_from_errno();
goto done;
}
if (!well_known) {
char *packed_refs_path;
FILE *f;
/* Search on-disk refs before packed refs! */
for (i = 0; i < nitems(subdirs); i++) {
err = open_ref(ref, path_refs, subdirs[i], refname);
if (err || *ref)
goto done;
}
packed_refs_path = got_repo_get_path_packed_refs(repo);
if (packed_refs_path == NULL) {
err = got_error_from_errno();
goto done;
}
f = fopen(packed_refs_path, "rb");
free(packed_refs_path);
if (f != NULL) {
err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
refname);
if (fclose(f) != 0 && err == NULL)
err = got_error_from_errno();
if (err || *ref)
goto done;
}
}
err = open_ref(ref, path_refs, "", refname);
if (err)
goto done;
done:
if (*ref == NULL)
err = got_error_not_ref(refname);
free(path_refs);
return err;
}
void
got_ref_close(struct got_reference *ref)
{
if (ref->flags & GOT_REF_IS_SYMBOLIC)
free(ref->ref.symref.name);
else
free(ref->ref.ref.name);
free(ref);
}
struct got_reference *
got_ref_dup(struct got_reference *ref)
{
struct got_reference *ret;
ret = calloc(1, sizeof(*ret));
if (ret == NULL)
return NULL;
ret->flags = ref->flags;
if (ref->flags & GOT_REF_IS_SYMBOLIC) {
ret->ref.symref.name = strdup(ref->ref.symref.name);
if (ret->ref.symref.name == NULL) {
free(ret);
return NULL;
}
ret->ref.symref.ref = strdup(ref->ref.symref.ref);
if (ret->ref.symref.ref == NULL) {
free(ret->ref.symref.name);
free(ret);
return NULL;
}
} else {
ref->ref.ref.name = strdup(ref->ref.ref.name);
if (ref->ref.ref.name == NULL) {
free(ret);
return NULL;
}
memcpy(ret->ref.ref.sha1, ref->ref.ref.sha1,
SHA1_DIGEST_LENGTH);
}
return ret;
}
static const struct got_error *
resolve_symbolic_ref(struct got_reference **resolved,
struct got_repository *repo, struct got_reference *ref)
{
struct got_reference *nextref;
const struct got_error *err;
err = got_ref_open(&nextref, repo, ref->ref.symref.ref);
if (err)
return err;
if (nextref->flags & GOT_REF_IS_SYMBOLIC)
err = resolve_symbolic_ref(resolved, repo, nextref);
else
*resolved = got_ref_dup(nextref);
got_ref_close(nextref);
return err;
}
const struct got_error *
got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
struct got_reference *ref)
{
const struct got_error *err;
if (ref->flags & GOT_REF_IS_SYMBOLIC) {
struct got_reference *resolved = NULL;
err = resolve_symbolic_ref(&resolved, repo, ref);
if (err == NULL)
err = got_ref_resolve(id, repo, resolved);
free(resolved);
return err;
}
*id = calloc(1, sizeof(**id));
if (*id == NULL)
return got_error_from_errno();
memcpy((*id)->sha1, ref->ref.ref.sha1, SHA1_DIGEST_LENGTH);
return NULL;
}
char *
got_ref_to_str(struct got_reference *ref)
{
char *str;
if (ref->flags & GOT_REF_IS_SYMBOLIC)
return strdup(ref->ref.symref.ref);
str = malloc(SHA1_DIGEST_STRING_LENGTH);
if (str == NULL)
return NULL;
if (got_sha1_digest_to_str(ref->ref.ref.sha1, str,
SHA1_DIGEST_STRING_LENGTH) == NULL) {
free(str);
return NULL;
}
return str;
}
const char *
got_ref_get_name(struct got_reference *ref)
{
if (ref->flags & GOT_REF_IS_SYMBOLIC)
return ref->ref.symref.name;
return ref->ref.ref.name;
}
static const struct got_error *
insert_ref(struct got_reflist_head *refs, struct got_reference *ref,
struct got_repository *repo)
{
const struct got_error *err;
struct got_object_id *id;
struct got_reflist_entry *new, *re, *prev;
int cmp;
err = got_ref_resolve(&id, repo, ref);
if (err)
return err;
new = malloc(sizeof(*re));
if (new == NULL) {
free(id);
return got_error_from_errno();
}
new->ref = ref;
new->id = id;
/*
* We must de-duplicate entries on insert because packed-refs may
* contain redundant entries. On-disk refs take precedence.
* This code assumes that on-disk revs are read before packed-refs.
* We're iterating the list anyway, so insert elements sorted by name.
*/
re = SIMPLEQ_FIRST(refs);
while (re) {
cmp = got_path_cmp(got_ref_get_name(re->ref),
got_ref_get_name(ref));
if (cmp == 0) {
free(ref); /* duplicate */
return NULL;
} else if (cmp > 0) {
if (prev)
SIMPLEQ_INSERT_AFTER(refs, prev, new, entry);
else
SIMPLEQ_INSERT_HEAD(refs, new, entry);
return NULL;
} else {
prev = re;
re = SIMPLEQ_NEXT(re, entry);
}
}
SIMPLEQ_INSERT_TAIL(refs, new, entry);
return NULL;
}
static const struct got_error *
gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
const char *subdir, struct got_repository *repo)
{
const struct got_error *err = NULL;
DIR *d = NULL;
char *path_subdir;
if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
return got_error_from_errno();
d = opendir(path_subdir);
if (d == NULL)
goto done;
while (1) {
struct dirent *dent;
struct got_reference *ref;
char *child;
dent = readdir(d);
if (dent == NULL)
break;
if (strcmp(dent->d_name, ".") == 0 ||
strcmp(dent->d_name, "..") == 0)
continue;
switch (dent->d_type) {
case DT_REG:
err = open_ref(&ref, path_refs, subdir, dent->d_name);
if (err)
goto done;
if (ref) {
err = insert_ref(refs, ref, repo);
if (err)
goto done;
}
break;
case DT_DIR:
if (asprintf(&child, "%s%s%s", subdir,
subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
err = got_error_from_errno();
break;
}
err = gather_on_disk_refs(refs, path_refs, child, repo);
free(child);
break;
default:
break;
}
}
done:
if (d)
closedir(d);
free(path_subdir);
return err;
}
const struct got_error *
got_ref_list(struct got_reflist_head *refs, struct got_repository *repo)
{
const struct got_error *err;
char *packed_refs_path, *path_refs = NULL;
FILE *f = NULL;
struct got_reference *ref;
/* HEAD ref should always exist. */
path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
if (path_refs == NULL) {
err = got_error_from_errno();
goto done;
}
err = open_ref(&ref, path_refs, "", GOT_REF_HEAD);
if (err)
goto done;
err = insert_ref(refs, ref, repo);
if (err)
goto done;
/* Gather on-disk refs before parsing packed-refs. */
free(path_refs);
path_refs = get_refs_dir_path(repo, "");
if (path_refs == NULL) {
err = got_error_from_errno();
goto done;
}
err = gather_on_disk_refs(refs, path_refs, "", repo);
if (err)
goto done;
/*
* The packed-refs file may contain redundant entries, in which
* case on-disk refs take precedence.
*/
packed_refs_path = got_repo_get_path_packed_refs(repo);
if (packed_refs_path == NULL) {
err = got_error_from_errno();
goto done;
}
f = fopen(packed_refs_path, "r");
free(packed_refs_path);
if (f) {
char *line;
size_t len;
const char delim[3] = {'\0', '\0', '\0'};
while (1) {
line = fparseln(f, &len, NULL, delim, 0);
if (line == NULL)
break;
err = parse_packed_ref_line(&ref, NULL, line);
if (err)
goto done;
if (ref) {
err = insert_ref(refs, ref, repo);
if (err)
goto done;
}
}
}
done:
free(path_refs);
if (f && fclose(f) != 0 && err == NULL)
err = got_error_from_errno();
return err;
}
