thodg/got/libexec/got-read-object/got-read-object.c

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• Hash : 876c234b
  Author :
  Date : 2018-09-10T12:30:47
  

  start reading pack files with privsep; still WIP

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• libexec/got-read-object/got-read-object.c

• /*
   * 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.
   */
  
  #include <sys/types.h>
  #include <sys/queue.h>
  #include <sys/uio.h>
  #include <sys/time.h>
  #include <sys/limits.h>
  #include <sys/syslimits.h>
  
  #include <stdint.h>
  #include <imsg.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <sha1.h>
  #include <zlib.h>
  
  #include "got_error.h"
  #include "got_object.h"
  
  #include "got_lib_delta.h"
  #include "got_lib_inflate.h"
  #include "got_lib_object.h"
  #include "got_lib_privsep.h"
  
  #ifndef nitems
  #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
  #endif
  
  #define GOT_OBJ_TAG_COMMIT	"commit"
  #define GOT_OBJ_TAG_TREE	"tree"
  #define GOT_OBJ_TAG_BLOB	"blob"
  
  static const struct got_error *
  parse_object_header(struct got_object **obj, char *buf, size_t len)
  {
  	const char *obj_tags[] = {
  		GOT_OBJ_TAG_COMMIT,
  		GOT_OBJ_TAG_TREE,
  		GOT_OBJ_TAG_BLOB
  	};
  	const int obj_types[] = {
  		GOT_OBJ_TYPE_COMMIT,
  		GOT_OBJ_TYPE_TREE,
  		GOT_OBJ_TYPE_BLOB,
  	};
  	int type = 0;
  	size_t size = 0, hdrlen = 0;
  	int i;
  	char *p = strchr(buf, '\0');
  
  	if (p == NULL)
  		return got_error(GOT_ERR_BAD_OBJ_HDR);
  
  	hdrlen = strlen(buf) + 1 /* '\0' */;
  
  	for (i = 0; i < nitems(obj_tags); i++) {
  		const char *tag = obj_tags[i];
  		size_t tlen = strlen(tag);
  		const char *errstr;
  
  		if (strncmp(buf, tag, tlen) != 0)
  			continue;
  
  		type = obj_types[i];
  		if (len <= tlen)
  			return got_error(GOT_ERR_BAD_OBJ_HDR);
  		size = strtonum(buf + tlen, 0, LONG_MAX, &errstr);
  		if (errstr != NULL)
  			return got_error(GOT_ERR_BAD_OBJ_HDR);
  		break;
  	}
  
  	if (type == 0)
  		return got_error(GOT_ERR_BAD_OBJ_HDR);
  
  	*obj = calloc(1, sizeof(**obj));
  	if (*obj == NULL)
  		return got_error_from_errno();
  	(*obj)->type = type;
  	(*obj)->hdrlen = hdrlen;
  	(*obj)->size = size;
  	return NULL;
  }
  
  static const struct got_error *
  read_object_header(struct got_object **obj, int fd)
  {
  	const struct got_error *err;
  	struct got_zstream_buf zb;
  	char *buf;
  	const size_t zbsize = 64;
  	size_t outlen, totlen;
  	int nbuf = 1;
  
  	buf = malloc(zbsize);
  	if (buf == NULL)
  		return got_error_from_errno();
  
  	err = got_inflate_init(&zb, buf, zbsize);
  	if (err)
  		return err;
  
  	totlen = 0;
  	do {
  		err = got_inflate_read_fd(&zb, fd, &outlen);
  		if (err)
  			goto done;
  		if (outlen == 0)
  			break;
  		totlen += outlen;
  		if (strchr(zb.outbuf, '\0') == NULL) {
  			char *newbuf;
  			nbuf++;
  			newbuf = recallocarray(buf, nbuf - 1, nbuf, zbsize);
  			if (newbuf == NULL) {
  				err = got_error_from_errno();
  				goto done;
  			}
  			buf = newbuf;
  			zb.outbuf = newbuf + totlen;
  			zb.outlen = (nbuf * zbsize) - totlen;
  		}
  	} while (strchr(zb.outbuf, '\0') == NULL);
  
  	err = parse_object_header(obj, buf, totlen);
  done:
  	free(buf);
  	got_inflate_end(&zb);
  	return err;
  }
  
  
  int
  main(int argc, char *argv[])
  {
  	const struct got_error *err = NULL;
  	struct got_object *obj = NULL;
  	struct imsg imsg;
  	struct imsgbuf ibuf;
  	size_t datalen;
  
  	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
  
  	/* revoke access to most system calls */
  	if (pledge("stdio recvfd", NULL) == -1) {
  		err = got_error_from_errno();
  		got_privsep_send_error(&ibuf, err);
  		return 1;
  	}
  
  	while (1) {
  		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
  		if (err) {
  			if (err->code == GOT_ERR_PRIVSEP_PIPE)
  				err = NULL;
  			break;
  		}
  
  		if (imsg.hdr.type == GOT_IMSG_STOP)
  			break;
  
  		if (imsg.hdr.type != GOT_IMSG_OBJECT_REQUEST) {
  			err = got_error(GOT_ERR_PRIVSEP_MSG);
  			goto done;
  		}
  
  		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
  		if (datalen != 0) {
  			err = got_error(GOT_ERR_PRIVSEP_LEN);
  			goto done;
  		}
  
  		err = read_object_header(&obj, imsg.fd);
  		if (err)
  			goto done;
  
  		err = got_privsep_send_obj(&ibuf, obj);
  done:
  		close(imsg.fd);
  		imsg_free(&imsg);
  		if (obj)
  			got_object_close(obj);
  		if (err) {
  			if (err->code == GOT_ERR_PRIVSEP_PIPE)
  				err = NULL;
  			else
  				got_privsep_send_error(&ibuf, err);
  			break;
  		}
  	}
  
  	imsg_clear(&ibuf);
  	if (err)
  		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
  	close(GOT_IMSG_FD_CHILD);
  	return err ? 1 : 0;
  }
  

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