libexec/got-read-blob/got-read-blob.c

   1 /*
   2  * Copyright (c) 2018, 2019 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                 imsgbuf_clear(&ibuf);
  73                 return 1;
  74         }
  75
  76         /* revoke fs access */
  77         if (landlock_no_fs() == -1) {
  78                 err = got_error_from_errno("landlock_no_fs");
  79                 got_privsep_send_error(&ibuf, err);
  80                 return 1;
  81         }
  82         if (cap_enter() == -1) {
  83                 err = got_error_from_errno("cap_enter");
  84                 got_privsep_send_error(&ibuf, err);
  85                 return 1;
  86         }
  87 #endif
  88
  89         for (;;) {
  90                 struct imsg imsg, imsg_outfd;
  91                 FILE *f = NULL;
  92                 int fd = -1, outfd = -1;
  93                 size_t size;
  94                 struct got_object *obj = NULL;
  95                 uint8_t *buf = NULL;
  96                 struct got_object_id id;
  97                 struct got_object_id expected_id;
  98                 struct got_inflate_checksum csum;
  99                 struct got_hash ctx;
 100
 101                 memset(&imsg, 0, sizeof(imsg));
 102                 memset(&imsg_outfd, 0, sizeof(imsg_outfd));
 103
 104                 if (sigint_received) {
 105                         err = got_error(GOT_ERR_CANCELLED);
 106                         break;
 107                 }
 108
 109                 err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
 110                 if (err) {
 111                         if (err->code == GOT_ERR_PRIVSEP_PIPE)
 112                                 err = NULL;
 113                         break;
 114                 }
 115
 116                 if (imsg.hdr.type == GOT_IMSG_STOP)
 117                         break;
 118
 119                 if (imsg.hdr.type != GOT_IMSG_BLOB_REQUEST) {
 120                         err = got_error(GOT_ERR_PRIVSEP_MSG);
 121                         goto done;
 122                 }
 123
 124                 datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
 125                 if (datalen != sizeof(expected_id)) {
 126                         err = got_error(GOT_ERR_PRIVSEP_LEN);
 127                         goto done;
 128                 }
 129                 memcpy(&expected_id, imsg.data, sizeof(expected_id));
 130
 131                 fd = imsg_get_fd(&imsg);
 132                 if (fd == -1) {
 133                         err = got_error(GOT_ERR_PRIVSEP_NO_FD);
 134                         goto done;
 135                 }
 136
 137                 err = got_privsep_recv_imsg(&imsg_outfd, &ibuf, 0);
 138                 if (err) {
 139                         if (imsg.hdr.len == 0)
 140                                 err = NULL;
 141                         break;
 142                 }
 143
 144                 if (imsg_outfd.hdr.type == GOT_IMSG_STOP)
 145                         break;
 146
 147                 if (imsg_outfd.hdr.type != GOT_IMSG_BLOB_OUTFD) {
 148                         err = got_error(GOT_ERR_PRIVSEP_MSG);
 149                         goto done;
 150                 }
 151
 152                 datalen = imsg_outfd.hdr.len - IMSG_HEADER_SIZE;
 153                 if (datalen != 0) {
 154                         err = got_error(GOT_ERR_PRIVSEP_LEN);
 155                         goto done;
 156                 }
 157                 outfd = imsg_get_fd(&imsg_outfd);
 158                 if (outfd == -1) {
 159                         err = got_error(GOT_ERR_PRIVSEP_NO_FD);
 160                         goto done;
 161                 }
 162
 163                 err = got_object_read_header(&obj, fd);
 164                 if (err)
 165                         goto done;
 166
 167                 if (lseek(fd, SEEK_SET, 0) == -1) {
 168                         err = got_error_from_errno("lseek");
 169                         goto done;
 170                 }
 171
 172                 f = fdopen(fd, "rb");
 173                 if (f == NULL) {
 174                         err = got_error_from_errno("fdopen");
 175                         goto done;
 176                 }
 177                 fd = -1;
 178
 179                 got_hash_init(&ctx, expected_id.algo);
 180                 memset(&csum, 0, sizeof(csum));
 181                 csum.output_ctx = &ctx;
 182
 183                 if (obj->size + obj->hdrlen <=
 184                     GOT_PRIVSEP_INLINE_BLOB_DATA_MAX) {
 185                         err = got_inflate_to_mem(&buf, &size, NULL, &csum, f);
 186                         if (err)
 187                                 goto done;
 188                 } else {
 189                         err = got_inflate_to_fd(&size, f, &csum, outfd);
 190                         if (err)
 191                                 goto done;
 192                 }
 193                 got_hash_final_object_id(&ctx, &id);
 194                 if (got_object_id_cmp(&expected_id, &id) != 0) {
 195                         err = got_error_checksum(&expected_id);
 196                         goto done;
 197                 }
 198
 199                 if (size < obj->hdrlen) {
 200                         err = got_error(GOT_ERR_BAD_OBJ_HDR);
 201                         goto done;
 202                 }
 203
 204                 err = got_privsep_send_blob(&ibuf, size, obj->hdrlen, buf);
 205 done:
 206                 free(buf);
 207                 if (f && fclose(f) == EOF && err == NULL)
 208                         err = got_error_from_errno("fclose");
 209                 if (fd != -1 && close(fd) == -1 && err == NULL)
 210                         err = got_error_from_errno("close");
 211                 if (outfd != -1 && close(outfd) == -1 && err == NULL)
 212                         err = got_error_from_errno("close");
 213
 214                 imsg_free(&imsg);
 215                 imsg_free(&imsg_outfd);
 216                 if (obj)
 217                         got_object_close(obj);
 218                 if (err)
 219                         break;
 220         }
 221
 222         if (err) {
 223                 if (!sigint_received && err->code != GOT_ERR_PRIVSEP_PIPE) {
 224                         fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
 225                         got_privsep_send_error(&ibuf, err);
 226                 }
 227         }
 228         imsgbuf_clear(&ibuf);
 229         if (close(GOT_IMSG_FD_CHILD) == -1 && err == NULL)
 230                 err = got_error_from_errno("close");
 231         return err ? 1 : 0;
 232 }