1 /*
   2  * This file and its contents are supplied under the terms of the
   3  * Common Development and Distribution License ("CDDL"), version 1.0.
   4  * You may only use this file in accordance with the terms of version
   5  * 1.0 of the CDDL.
   6  *
   7  * A full copy of the text of the CDDL should have accompanied this
   8  * source.  A copy of the CDDL is also available via the Internet at
   9  * http://www.illumos.org/license/CDDL.
  10  */
  11 
  12 /*
  13  * Copyright 2020 Joyent, Inc.
  14  */
  15 
  16 #include <sys/uio.h>
  17 #include <strings.h>
  18 #include <limits.h>
  19 #include <unistd.h>
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22 #include <errno.h>
  23 #include <err.h>
  24 
  25 #define ONE_GIG ((off_t)1024 * 1024 * 1024)
  26 
  27 #define DATA_LEN (sizeof ("data"))
  28 
  29 /*
  30  * Some simple testing of the read/writev() family: specifically we're checking
  31  * IOV_MAX == 1024, and that a large-file compiled 32-bit binary can correctly
  32  * access certain offsets.
  33  */
  34 
  35 int
  36 main(int argc, char *argv[])
  37 {
  38         char path[] = "/var/tmp/writev_test.XXXXXX";
  39         char data[(IOV_MAX + 1) * DATA_LEN] = "";
  40         struct iovec iov[IOV_MAX + 1];
  41 
  42         if (IOV_MAX < 1024)
  43                 errx(EXIT_FAILURE, "IOV_MAX != 1024");
  44 
  45         int fd = mkstemp(path);
  46 
  47         if (fd == -1)
  48                 err(EXIT_FAILURE, "failed to create file");
  49 
  50         int ret = ftruncate(fd, ONE_GIG * 8);
  51 
  52         if (ret != 0)
  53                 err(EXIT_FAILURE, "failed to truncate file");
  54 
  55         for (int i = 0; i < IOV_MAX + 1; i++) {
  56                 (void) strcpy(data + i * DATA_LEN, "data");
  57                 iov[i].iov_base = data + i * 5;
  58                 iov[i].iov_len = DATA_LEN;
  59         }
  60 
  61         ssize_t written = writev(fd, iov, IOV_MAX + 1);
  62 
  63         if (written != -1 || errno != EINVAL)
  64                 errx(EXIT_FAILURE, "writev(IOV_MAX + 1) didn't fail properly");
  65 
  66         written = writev(fd, iov, IOV_MAX);
  67 
  68         if (written == -1)
  69                 err(EXIT_FAILURE, "writev failed");
  70 
  71         bzero(data, sizeof (data));
  72 
  73         ssize_t read = preadv(fd, iov, IOV_MAX, 0);
  74 
  75         if (read != DATA_LEN * IOV_MAX)
  76                 err(EXIT_FAILURE, "preadv failed");
  77 
  78         for (int i = 0; i < IOV_MAX; i++) {
  79                 if (strcmp(data + i * DATA_LEN, "data") != 0)
  80                         errx(EXIT_FAILURE, "bad read at 0x%lx", i * DATA_LEN);
  81         }
  82 
  83         /*
  84          * Now test various "interesting" offsets.
  85          */
  86 
  87         for (off_t off = 0; off < ONE_GIG * 8; off += ONE_GIG) {
  88                 if ((written = pwritev(fd, iov, 1, off)) != DATA_LEN)
  89                         err(EXIT_FAILURE, "pwritev(0x%lx) failed", off);
  90         }
  91 
  92         for (off_t off = 0; off < ONE_GIG * 8; off += ONE_GIG) {
  93                 if ((read = preadv(fd, iov, 1, off)) != DATA_LEN)
  94                         err(EXIT_FAILURE, "preadv(0x%lx) failed", off);
  95                 if (strcmp(data, "data") != 0)
  96                         errx(EXIT_FAILURE, "bad read at 0x%lx", off);
  97         }
  98 
  99         (void) unlink(path);
 100 
 101         return (EXIT_SUCCESS);
 102 }