lib/libpuffs/requests.c

   1 /*      $NetBSD: requests.c,v 1.24 2013/01/23 20:22:34 riastradh Exp $  */
   2
   3 /*
   4  * Copyright (c) 2007 Antti Kantee.  All Rights Reserved.
   5  *
   6  * Development of this software was supported by the
   7  * Research Foundation of Helsinki University of Technology
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
  19  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  21  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32 #if !defined(lint)
  33 __RCSID("$NetBSD: requests.c,v 1.24 2013/01/23 20:22:34 riastradh Exp $");
  34 #endif /* !lint */
  35
  36 #include <sys/types.h>
  37 #include <sys/ioctl.h>
  38 #include <sys/queue.h>
  39 #include <sys/socket.h>
  40
  41 #if !defined(__minix)
  42 #include <dev/putter/putter.h>
  43 #endif /* !defined(__minix) */
  44
  45 #include <assert.h>
  46 #include <errno.h>
  47 #include <puffs.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <unistd.h>
  51
  52 #include "puffs_priv.h"
  53
  54 /*
  55  * Read a frame from the upstream provider.  First read the frame
  56  * length and after this read the actual contents.  Yes, optimize
  57  * me some day.
  58  */
  59 /*ARGSUSED*/
  60 int
  61 puffs__fsframe_read(struct puffs_usermount *pu, struct puffs_framebuf *pb,
  62         int fd, int *done)
  63 {
  64         struct putter_hdr phdr;
  65         void *win;
  66         size_t howmuch, winlen, curoff;
  67         ssize_t n;
  68         int lenstate;
  69
  70         /* How much to read? */
  71  the_next_level:
  72         curoff = puffs_framebuf_telloff(pb);
  73         if (curoff < sizeof(struct putter_hdr)) {
  74                 howmuch = sizeof(struct putter_hdr) - curoff;
  75                 lenstate = 1;
  76         } else {
  77                 puffs_framebuf_getdata_atoff(pb, 0, &phdr, sizeof(phdr));
  78                 /*LINTED*/
  79                 howmuch = phdr.pth_framelen - curoff;
  80                 lenstate = 0;
  81         }
  82
  83         if (puffs_framebuf_reserve_space(pb, howmuch) == -1)
  84                 return errno;
  85
  86         /* Read contents */
  87         while (howmuch) {
  88                 winlen = howmuch;
  89                 curoff = puffs_framebuf_telloff(pb);
  90                 if (puffs_framebuf_getwindow(pb, curoff, &win, &winlen) == -1)
  91                         return errno;
  92                 n = read(fd, win, winlen);
  93                 switch (n) {
  94                 case 0:
  95                         return ECONNRESET;
  96                 case -1:
  97                         if (errno == EAGAIN)
  98                                 return 0;
  99                         return errno;
 100                 default:
 101                         howmuch -= n;
 102                         puffs_framebuf_seekset(pb, curoff + n);
 103                         break;
 104                 }
 105         }
 106
 107         if (lenstate)
 108                 goto the_next_level;
 109
 110         puffs_framebuf_seekset(pb, 0);
 111         *done = 1;
 112         return 0;
 113 }
 114
 115 /*
 116  * Write a frame upstream
 117  */
 118 /*ARGSUSED*/
 119 int
 120 puffs__fsframe_write(struct puffs_usermount *pu, struct puffs_framebuf *pb,
 121         int fd, int *done)
 122 {
 123         void *win;
 124         uint64_t flen;
 125         size_t winlen, howmuch, curoff;
 126         ssize_t n;
 127         int rv;
 128
 129         /*
 130          * Finalize it if we haven't written anything yet (or we're still
 131          * attempting to write the first byte)
 132          *
 133          * XXX: this shouldn't be here
 134          */
 135         if (puffs_framebuf_telloff(pb) == 0) {
 136                 struct puffs_req *preq;
 137
 138                 winlen = sizeof(struct puffs_req);
 139                 rv = puffs_framebuf_getwindow(pb, 0, (void *)&preq, &winlen);
 140                 if (rv == -1)
 141                         return errno;
 142                 preq->preq_pth.pth_framelen = flen = preq->preq_buflen;
 143         } else {
 144                 struct putter_hdr phdr;
 145
 146                 puffs_framebuf_getdata_atoff(pb, 0, &phdr, sizeof(phdr));
 147                 flen = phdr.pth_framelen;
 148         }
 149
 150         /*
 151          * Then write it.  Chances are if we are talking to the kernel it'll
 152          * just shlosh in all at once, but if we're e.g. talking to the
 153          * network it might take a few tries.
 154          */
 155         /*LINTED*/
 156         howmuch = flen - puffs_framebuf_telloff(pb);
 157
 158         while (howmuch) {
 159                 winlen = howmuch;
 160                 curoff = puffs_framebuf_telloff(pb);
 161                 if (puffs_framebuf_getwindow(pb, curoff, &win, &winlen) == -1)
 162                         return errno;
 163
 164                 /*
 165                  * XXX: we know from the framebuf implementation that we
 166                  * will always managed to map the entire window.  But if
 167                  * that changes, this will catch it.  Then we can do stuff
 168                  * iov stuff instead.
 169                  */
 170                 assert(winlen == howmuch);
 171
 172                 /* XXX: want NOSIGNAL if writing to a pipe */
 173 #if 0
 174                 n = send(fd, win, winlen, MSG_NOSIGNAL);
 175 #else
 176                 n = write(fd, win, winlen);
 177 #endif
 178                 switch (n) {
 179                 case 0:
 180                         return ECONNRESET;
 181                 case -1:
 182                         if (errno == EAGAIN)
 183                                 return 0;
 184                         return errno;
 185                 default:
 186                         howmuch -= n;
 187                         puffs_framebuf_seekset(pb, curoff + n);
 188                         break;
 189                 }
 190         }
 191
 192         *done = 1;
 193         return 0;
 194 }
 195
 196 /*
 197  * Compare if "pb1" is a response to a previously sent frame pb2.
 198  * More often than not "pb1" is not a response to anything but
 199  * rather a fresh request from the kernel.
 200  */
 201 /*ARGSUSED*/
 202 int
 203 puffs__fsframe_cmp(struct puffs_usermount *pu,
 204         struct puffs_framebuf *pb1, struct puffs_framebuf *pb2, int *notresp)
 205 {
 206         struct puffs_req *preq1, *preq2;
 207         size_t winlen;
 208         int rv;
 209
 210         /* map incoming preq */
 211         winlen = sizeof(struct puffs_req);
 212         rv = puffs_framebuf_getwindow(pb1, 0, (void *)&preq1, &winlen);
 213         assert(rv == 0); /* frames are always at least puffs_req in size */
 214         assert(winlen == sizeof(struct puffs_req));
 215
 216         /*
 217          * Check if this is not a response in this slot.  That's the
 218          * likely case.
 219          */
 220         if ((preq1->preq_opclass & PUFFSOPFLAG_ISRESPONSE) == 0) {
 221                 *notresp = 1;
 222                 return 0;
 223         }
 224
 225         /* map second preq */
 226         winlen = sizeof(struct puffs_req);
 227         rv = puffs_framebuf_getwindow(pb2, 0, (void *)&preq2, &winlen);
 228         assert(rv == 0); /* frames are always at least puffs_req in size */
 229         assert(winlen == sizeof(struct puffs_req));
 230
 231         /* then compare: resid equal? */
 232         return preq1->preq_id != preq2->preq_id;
 233 }
 234
 235 void
 236 puffs__fsframe_gotframe(struct puffs_usermount *pu, struct puffs_framebuf *pb)
 237 {
 238
 239         puffs_framebuf_seekset(pb, 0);
 240         puffs__ml_dispatch(pu, pb);
 241 }