libexec/got-read-tag/got-read-tag.c

   1 /*
   2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include <sys/types.h>
  18 #include <sys/queue.h>
  19 #include <sys/uio.h>
  20 #include <sys/time.h>
  21
  22 #include <err.h>
  23 #include <stdint.h>
  24 #include <limits.h>
  25 #include <signal.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30 #include <zlib.h>
  31
  32 #include "got_compat.h"
  33
  34 #include "got_error.h"
  35 #include "got_object.h"
  36
  37 #include "got_lib_delta.h"
  38 #include "got_lib_hash.h"
  39 #include "got_lib_inflate.h"
  40 #include "got_lib_object.h"
  41 #include "got_lib_object_parse.h"
  42 #include "got_lib_privsep.h"
  43
  44 static volatile sig_atomic_t sigint_received;
  45
  46 static void
  47 catch_sigint(int signo)
  48 {
  49         sigint_received = 1;
  50 }
  51
  52 int
  53 main(int argc, char *argv[])
  54 {
  55         const struct got_error *err = NULL;
  56         struct imsgbuf ibuf;
  57         size_t datalen;
  58
  59         signal(SIGINT, catch_sigint);
  60
  61         if (imsgbuf_init(&ibuf, GOT_IMSG_FD_CHILD) == -1) {
  62                 warn("imsgbuf_init");
  63                 return 1;
  64         }
  65         imsgbuf_allow_fdpass(&ibuf);
  66
  67 #ifndef PROFILE
  68         /* revoke access to most system calls */
  69         if (pledge("stdio recvfd", NULL) == -1) {
  70                 err = got_error_from_errno("pledge");
  71                 got_privsep_send_error(&ibuf, err);
  72                 return 1;
  73         }
  74
  75         /* revoke fs access */
  76         if (landlock_no_fs() == -1) {
  77                 err = got_error_from_errno("landlock_no_fs");
  78                 got_privsep_send_error(&ibuf, err);
  79                 return 1;
  80         }
  81         if (cap_enter() == -1) {
  82                 err = got_error_from_errno("cap_enter");
  83                 got_privsep_send_error(&ibuf, err);
  84                 return 1;
  85         }
  86 #endif
  87
  88         for (;;) {
  89                 struct imsg imsg;
  90                 struct got_tag_object *tag = NULL;
  91                 struct got_object_id expected_id;
  92                 int fd = -1;
  93
  94                 if (sigint_received) {
  95                         err = got_error(GOT_ERR_CANCELLED);
  96                         break;
  97                 }
  98
  99                 err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
 100                 if (err) {
 101                         if (err->code == GOT_ERR_PRIVSEP_PIPE)
 102                                 err = NULL;
 103                         break;
 104                 }
 105
 106                 if (imsg.hdr.type == GOT_IMSG_STOP)
 107                         break;
 108
 109                 if (imsg.hdr.type != GOT_IMSG_TAG_REQUEST) {
 110                         err = got_error(GOT_ERR_PRIVSEP_MSG);
 111                         goto done;
 112                 }
 113
 114                 datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
 115                 if (datalen != sizeof(expected_id)) {
 116                         err = got_error(GOT_ERR_PRIVSEP_LEN);
 117                         goto done;
 118                 }
 119                 memcpy(&expected_id, imsg.data, sizeof(expected_id));
 120
 121                 fd = imsg_get_fd(&imsg);
 122                 if (fd == -1) {
 123                         err = got_error(GOT_ERR_PRIVSEP_NO_FD);
 124                         goto done;
 125                 }
 126
 127                 /* Always assume file offset zero. */
 128                 err = got_object_read_tag(&tag, fd, &expected_id, 0);
 129                 if (err)
 130                         goto done;
 131
 132                 err = got_privsep_send_tag(&ibuf, tag);
 133 done:
 134                 if (fd != -1 && close(fd) == -1 && err == NULL)
 135                         err = got_error_from_errno("close");
 136                 imsg_free(&imsg);
 137                 if (err)
 138                         break;
 139         }
 140
 141         imsgbuf_clear(&ibuf);
 142         if (err) {
 143                 if (!sigint_received && err->code != GOT_ERR_PRIVSEP_PIPE) {
 144                         fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
 145                         got_privsep_send_error(&ibuf, err);
 146                 }
 147         }
 148         if (close(GOT_IMSG_FD_CHILD) == -1 && err == NULL)
 149                 err = got_error_from_errno("close");
 150         return err ? 1 : 0;
 151 }