Revision b4eafbcdb84fc406bff37f06fdf6310aca7d0249 authored by Junio C Hamano on 21 November 2018, 13:57:44 UTC, committed by Junio C Hamano on 21 November 2018, 13:57:44 UTC
A corner case bugfix in "git rerere" code. * en/rerere-multi-stage-1-fix: rerere: avoid buffer overrun t4200: demonstrate rerere segfault on specially crafted merge
cat-file.c
/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#include "cache.h"
#include "config.h"
#include "builtin.h"
#include "diff.h"
#include "parse-options.h"
#include "userdiff.h"
#include "streaming.h"
#include "tree-walk.h"
#include "sha1-array.h"
#include "packfile.h"
#include "object-store.h"
struct batch_options {
int enabled;
int follow_symlinks;
int print_contents;
int buffer_output;
int all_objects;
int unordered;
int cmdmode; /* may be 'w' or 'c' for --filters or --textconv */
const char *format;
};
static const char *force_path;
static int filter_object(const char *path, unsigned mode,
const struct object_id *oid,
char **buf, unsigned long *size)
{
enum object_type type;
*buf = read_object_file(oid, &type, size);
if (!*buf)
return error(_("cannot read object %s '%s'"),
oid_to_hex(oid), path);
if ((type == OBJ_BLOB) && S_ISREG(mode)) {
struct strbuf strbuf = STRBUF_INIT;
if (convert_to_working_tree(&the_index, path, *buf, *size, &strbuf)) {
free(*buf);
*size = strbuf.len;
*buf = strbuf_detach(&strbuf, NULL);
}
}
return 0;
}
static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
int unknown_type)
{
struct object_id oid;
enum object_type type;
char *buf;
unsigned long size;
struct object_context obj_context;
struct object_info oi = OBJECT_INFO_INIT;
struct strbuf sb = STRBUF_INIT;
unsigned flags = OBJECT_INFO_LOOKUP_REPLACE;
const char *path = force_path;
if (unknown_type)
flags |= OBJECT_INFO_ALLOW_UNKNOWN_TYPE;
if (get_oid_with_context(obj_name, GET_OID_RECORD_PATH,
&oid, &obj_context))
die("Not a valid object name %s", obj_name);
if (!path)
path = obj_context.path;
if (obj_context.mode == S_IFINVALID)
obj_context.mode = 0100644;
buf = NULL;
switch (opt) {
case 't':
oi.type_name = &sb;
if (oid_object_info_extended(the_repository, &oid, &oi, flags) < 0)
die("git cat-file: could not get object info");
if (sb.len) {
printf("%s\n", sb.buf);
strbuf_release(&sb);
return 0;
}
break;
case 's':
oi.sizep = &size;
if (oid_object_info_extended(the_repository, &oid, &oi, flags) < 0)
die("git cat-file: could not get object info");
printf("%lu\n", size);
return 0;
case 'e':
return !has_object_file(&oid);
case 'w':
if (!path)
die("git cat-file --filters %s: <object> must be "
"<sha1:path>", obj_name);
if (filter_object(path, obj_context.mode,
&oid, &buf, &size))
return -1;
break;
case 'c':
if (!path)
die("git cat-file --textconv %s: <object> must be <sha1:path>",
obj_name);
if (textconv_object(path, obj_context.mode, &oid, 1, &buf, &size))
break;
/* else fallthrough */
case 'p':
type = oid_object_info(the_repository, &oid, NULL);
if (type < 0)
die("Not a valid object name %s", obj_name);
/* custom pretty-print here */
if (type == OBJ_TREE) {
const char *ls_args[3] = { NULL };
ls_args[0] = "ls-tree";
ls_args[1] = obj_name;
return cmd_ls_tree(2, ls_args, NULL);
}
if (type == OBJ_BLOB)
return stream_blob_to_fd(1, &oid, NULL, 0);
buf = read_object_file(&oid, &type, &size);
if (!buf)
die("Cannot read object %s", obj_name);
/* otherwise just spit out the data */
break;
case 0:
if (type_from_string(exp_type) == OBJ_BLOB) {
struct object_id blob_oid;
if (oid_object_info(the_repository, &oid, NULL) == OBJ_TAG) {
char *buffer = read_object_file(&oid, &type,
&size);
const char *target;
if (!skip_prefix(buffer, "object ", &target) ||
get_oid_hex(target, &blob_oid))
die("%s not a valid tag", oid_to_hex(&oid));
free(buffer);
} else
oidcpy(&blob_oid, &oid);
if (oid_object_info(the_repository, &blob_oid, NULL) == OBJ_BLOB)
return stream_blob_to_fd(1, &blob_oid, NULL, 0);
/*
* we attempted to dereference a tag to a blob
* and failed; there may be new dereference
* mechanisms this code is not aware of.
* fall-back to the usual case.
*/
}
buf = read_object_with_reference(&oid, exp_type, &size, NULL);
break;
default:
die("git cat-file: unknown option: %s", exp_type);
}
if (!buf)
die("git cat-file %s: bad file", obj_name);
write_or_die(1, buf, size);
free(buf);
free(obj_context.path);
return 0;
}
struct expand_data {
struct object_id oid;
enum object_type type;
unsigned long size;
off_t disk_size;
const char *rest;
struct object_id delta_base_oid;
/*
* If mark_query is true, we do not expand anything, but rather
* just mark the object_info with items we wish to query.
*/
int mark_query;
/*
* Whether to split the input on whitespace before feeding it to
* get_sha1; this is decided during the mark_query phase based on
* whether we have a %(rest) token in our format.
*/
int split_on_whitespace;
/*
* After a mark_query run, this object_info is set up to be
* passed to sha1_object_info_extended. It will point to the data
* elements above, so you can retrieve the response from there.
*/
struct object_info info;
/*
* This flag will be true if the requested batch format and options
* don't require us to call sha1_object_info, which can then be
* optimized out.
*/
unsigned skip_object_info : 1;
};
static int is_atom(const char *atom, const char *s, int slen)
{
int alen = strlen(atom);
return alen == slen && !memcmp(atom, s, alen);
}
static void expand_atom(struct strbuf *sb, const char *atom, int len,
void *vdata)
{
struct expand_data *data = vdata;
if (is_atom("objectname", atom, len)) {
if (!data->mark_query)
strbuf_addstr(sb, oid_to_hex(&data->oid));
} else if (is_atom("objecttype", atom, len)) {
if (data->mark_query)
data->info.typep = &data->type;
else
strbuf_addstr(sb, type_name(data->type));
} else if (is_atom("objectsize", atom, len)) {
if (data->mark_query)
data->info.sizep = &data->size;
else
strbuf_addf(sb, "%lu", data->size);
} else if (is_atom("objectsize:disk", atom, len)) {
if (data->mark_query)
data->info.disk_sizep = &data->disk_size;
else
strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
} else if (is_atom("rest", atom, len)) {
if (data->mark_query)
data->split_on_whitespace = 1;
else if (data->rest)
strbuf_addstr(sb, data->rest);
} else if (is_atom("deltabase", atom, len)) {
if (data->mark_query)
data->info.delta_base_sha1 = data->delta_base_oid.hash;
else
strbuf_addstr(sb,
oid_to_hex(&data->delta_base_oid));
} else
die("unknown format element: %.*s", len, atom);
}
static size_t expand_format(struct strbuf *sb, const char *start, void *data)
{
const char *end;
if (*start != '(')
return 0;
end = strchr(start + 1, ')');
if (!end)
die("format element '%s' does not end in ')'", start);
expand_atom(sb, start + 1, end - start - 1, data);
return end - start + 1;
}
static void batch_write(struct batch_options *opt, const void *data, int len)
{
if (opt->buffer_output) {
if (fwrite(data, 1, len, stdout) != len)
die_errno("unable to write to stdout");
} else
write_or_die(1, data, len);
}
static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
{
const struct object_id *oid = &data->oid;
assert(data->info.typep);
if (data->type == OBJ_BLOB) {
if (opt->buffer_output)
fflush(stdout);
if (opt->cmdmode) {
char *contents;
unsigned long size;
if (!data->rest)
die("missing path for '%s'", oid_to_hex(oid));
if (opt->cmdmode == 'w') {
if (filter_object(data->rest, 0100644, oid,
&contents, &size))
die("could not convert '%s' %s",
oid_to_hex(oid), data->rest);
} else if (opt->cmdmode == 'c') {
enum object_type type;
if (!textconv_object(data->rest, 0100644, oid,
1, &contents, &size))
contents = read_object_file(oid,
&type,
&size);
if (!contents)
die("could not convert '%s' %s",
oid_to_hex(oid), data->rest);
} else
BUG("invalid cmdmode: %c", opt->cmdmode);
batch_write(opt, contents, size);
free(contents);
} else if (stream_blob_to_fd(1, oid, NULL, 0) < 0)
die("unable to stream %s to stdout", oid_to_hex(oid));
}
else {
enum object_type type;
unsigned long size;
void *contents;
contents = read_object_file(oid, &type, &size);
if (!contents)
die("object %s disappeared", oid_to_hex(oid));
if (type != data->type)
die("object %s changed type!?", oid_to_hex(oid));
if (data->info.sizep && size != data->size)
die("object %s changed size!?", oid_to_hex(oid));
batch_write(opt, contents, size);
free(contents);
}
}
static void batch_object_write(const char *obj_name,
struct strbuf *scratch,
struct batch_options *opt,
struct expand_data *data)
{
if (!data->skip_object_info &&
oid_object_info_extended(the_repository, &data->oid, &data->info,
OBJECT_INFO_LOOKUP_REPLACE) < 0) {
printf("%s missing\n",
obj_name ? obj_name : oid_to_hex(&data->oid));
fflush(stdout);
return;
}
strbuf_reset(scratch);
strbuf_expand(scratch, opt->format, expand_format, data);
strbuf_addch(scratch, '\n');
batch_write(opt, scratch->buf, scratch->len);
if (opt->print_contents) {
print_object_or_die(opt, data);
batch_write(opt, "\n", 1);
}
}
static void batch_one_object(const char *obj_name,
struct strbuf *scratch,
struct batch_options *opt,
struct expand_data *data)
{
struct object_context ctx;
int flags = opt->follow_symlinks ? GET_OID_FOLLOW_SYMLINKS : 0;
enum follow_symlinks_result result;
result = get_oid_with_context(obj_name, flags, &data->oid, &ctx);
if (result != FOUND) {
switch (result) {
case MISSING_OBJECT:
printf("%s missing\n", obj_name);
break;
case DANGLING_SYMLINK:
printf("dangling %"PRIuMAX"\n%s\n",
(uintmax_t)strlen(obj_name), obj_name);
break;
case SYMLINK_LOOP:
printf("loop %"PRIuMAX"\n%s\n",
(uintmax_t)strlen(obj_name), obj_name);
break;
case NOT_DIR:
printf("notdir %"PRIuMAX"\n%s\n",
(uintmax_t)strlen(obj_name), obj_name);
break;
default:
BUG("unknown get_sha1_with_context result %d\n",
result);
break;
}
fflush(stdout);
return;
}
if (ctx.mode == 0) {
printf("symlink %"PRIuMAX"\n%s\n",
(uintmax_t)ctx.symlink_path.len,
ctx.symlink_path.buf);
fflush(stdout);
return;
}
batch_object_write(obj_name, scratch, opt, data);
}
struct object_cb_data {
struct batch_options *opt;
struct expand_data *expand;
struct oidset *seen;
struct strbuf *scratch;
};
static int batch_object_cb(const struct object_id *oid, void *vdata)
{
struct object_cb_data *data = vdata;
oidcpy(&data->expand->oid, oid);
batch_object_write(NULL, data->scratch, data->opt, data->expand);
return 0;
}
static int collect_loose_object(const struct object_id *oid,
const char *path,
void *data)
{
oid_array_append(data, oid);
return 0;
}
static int collect_packed_object(const struct object_id *oid,
struct packed_git *pack,
uint32_t pos,
void *data)
{
oid_array_append(data, oid);
return 0;
}
static int batch_unordered_object(const struct object_id *oid, void *vdata)
{
struct object_cb_data *data = vdata;
if (oidset_insert(data->seen, oid))
return 0;
return batch_object_cb(oid, data);
}
static int batch_unordered_loose(const struct object_id *oid,
const char *path,
void *data)
{
return batch_unordered_object(oid, data);
}
static int batch_unordered_packed(const struct object_id *oid,
struct packed_git *pack,
uint32_t pos,
void *data)
{
return batch_unordered_object(oid, data);
}
static int batch_objects(struct batch_options *opt)
{
struct strbuf input = STRBUF_INIT;
struct strbuf output = STRBUF_INIT;
struct expand_data data;
int save_warning;
int retval = 0;
if (!opt->format)
opt->format = "%(objectname) %(objecttype) %(objectsize)";
/*
* Expand once with our special mark_query flag, which will prime the
* object_info to be handed to sha1_object_info_extended for each
* object.
*/
memset(&data, 0, sizeof(data));
data.mark_query = 1;
strbuf_expand(&output, opt->format, expand_format, &data);
data.mark_query = 0;
strbuf_release(&output);
if (opt->cmdmode)
data.split_on_whitespace = 1;
if (opt->all_objects) {
struct object_info empty = OBJECT_INFO_INIT;
if (!memcmp(&data.info, &empty, sizeof(empty)))
data.skip_object_info = 1;
}
/*
* If we are printing out the object, then always fill in the type,
* since we will want to decide whether or not to stream.
*/
if (opt->print_contents)
data.info.typep = &data.type;
if (opt->all_objects) {
struct object_cb_data cb;
if (repository_format_partial_clone)
warning("This repository has extensions.partialClone set. Some objects may not be loaded.");
cb.opt = opt;
cb.expand = &data;
cb.scratch = &output;
if (opt->unordered) {
struct oidset seen = OIDSET_INIT;
cb.seen = &seen;
for_each_loose_object(batch_unordered_loose, &cb, 0);
for_each_packed_object(batch_unordered_packed, &cb,
FOR_EACH_OBJECT_PACK_ORDER);
oidset_clear(&seen);
} else {
struct oid_array sa = OID_ARRAY_INIT;
for_each_loose_object(collect_loose_object, &sa, 0);
for_each_packed_object(collect_packed_object, &sa, 0);
oid_array_for_each_unique(&sa, batch_object_cb, &cb);
oid_array_clear(&sa);
}
strbuf_release(&output);
return 0;
}
/*
* We are going to call get_sha1 on a potentially very large number of
* objects. In most large cases, these will be actual object sha1s. The
* cost to double-check that each one is not also a ref (just so we can
* warn) ends up dwarfing the actual cost of the object lookups
* themselves. We can work around it by just turning off the warning.
*/
save_warning = warn_on_object_refname_ambiguity;
warn_on_object_refname_ambiguity = 0;
while (strbuf_getline(&input, stdin) != EOF) {
if (data.split_on_whitespace) {
/*
* Split at first whitespace, tying off the beginning
* of the string and saving the remainder (or NULL) in
* data.rest.
*/
char *p = strpbrk(input.buf, " \t");
if (p) {
while (*p && strchr(" \t", *p))
*p++ = '\0';
}
data.rest = p;
}
batch_one_object(input.buf, &output, opt, &data);
}
strbuf_release(&input);
strbuf_release(&output);
warn_on_object_refname_ambiguity = save_warning;
return retval;
}
static const char * const cat_file_usage[] = {
N_("git cat-file (-t [--allow-unknown-type] | -s [--allow-unknown-type] | -e | -p | <type> | --textconv | --filters) [--path=<path>] <object>"),
N_("git cat-file (--batch | --batch-check) [--follow-symlinks] [--textconv | --filters]"),
NULL
};
static int git_cat_file_config(const char *var, const char *value, void *cb)
{
if (userdiff_config(var, value) < 0)
return -1;
return git_default_config(var, value, cb);
}
static int batch_option_callback(const struct option *opt,
const char *arg,
int unset)
{
struct batch_options *bo = opt->value;
if (bo->enabled) {
return 1;
}
bo->enabled = 1;
bo->print_contents = !strcmp(opt->long_name, "batch");
bo->format = arg;
return 0;
}
int cmd_cat_file(int argc, const char **argv, const char *prefix)
{
int opt = 0;
const char *exp_type = NULL, *obj_name = NULL;
struct batch_options batch = {0};
int unknown_type = 0;
const struct option options[] = {
OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
OPT_CMDMODE('e', NULL, &opt,
N_("exit with zero when there's no error"), 'e'),
OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
OPT_CMDMODE(0, "textconv", &opt,
N_("for blob objects, run textconv on object's content"), 'c'),
OPT_CMDMODE(0, "filters", &opt,
N_("for blob objects, run filters on object's content"), 'w'),
OPT_STRING(0, "path", &force_path, N_("blob"),
N_("use a specific path for --textconv/--filters")),
OPT_BOOL(0, "allow-unknown-type", &unknown_type,
N_("allow -s and -t to work with broken/corrupt objects")),
OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
{ OPTION_CALLBACK, 0, "batch", &batch, "format",
N_("show info and content of objects fed from the standard input"),
PARSE_OPT_OPTARG, batch_option_callback },
{ OPTION_CALLBACK, 0, "batch-check", &batch, "format",
N_("show info about objects fed from the standard input"),
PARSE_OPT_OPTARG, batch_option_callback },
OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
N_("follow in-tree symlinks (used with --batch or --batch-check)")),
OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
N_("show all objects with --batch or --batch-check")),
OPT_BOOL(0, "unordered", &batch.unordered,
N_("do not order --batch-all-objects output")),
OPT_END()
};
git_config(git_cat_file_config, NULL);
batch.buffer_output = -1;
argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
if (opt) {
if (batch.enabled && (opt == 'c' || opt == 'w'))
batch.cmdmode = opt;
else if (argc == 1)
obj_name = argv[0];
else
usage_with_options(cat_file_usage, options);
}
if (!opt && !batch.enabled) {
if (argc == 2) {
exp_type = argv[0];
obj_name = argv[1];
} else
usage_with_options(cat_file_usage, options);
}
if (batch.enabled) {
if (batch.cmdmode != opt || argc)
usage_with_options(cat_file_usage, options);
if (batch.cmdmode && batch.all_objects)
die("--batch-all-objects cannot be combined with "
"--textconv nor with --filters");
}
if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
usage_with_options(cat_file_usage, options);
}
if (force_path && opt != 'c' && opt != 'w') {
error("--path=<path> needs --textconv or --filters");
usage_with_options(cat_file_usage, options);
}
if (force_path && batch.enabled) {
error("--path=<path> incompatible with --batch");
usage_with_options(cat_file_usage, options);
}
if (batch.buffer_output < 0)
batch.buffer_output = batch.all_objects;
if (batch.enabled)
return batch_objects(&batch);
if (unknown_type && opt != 't' && opt != 's')
die("git cat-file --allow-unknown-type: use with -s or -t");
return cat_one_file(opt, exp_type, obj_name, unknown_type);
}
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