lib/libpuffs/requests.c

   1 /*      $NetBSD: requests.c,v 1.23 2008/01/29 14:54:08 pooka 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/types.h>
  32 #include <sys/ioctl.h>
  33 #include <sys/queue.h>
  34 #include <sys/socket.h>
  35
  36 #include <dev/misc/putter/putter.h>
  37
  38 #include <assert.h>
  39 #include <errno.h>
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <unistd.h>
  43
  44 #include "puffs.h"
  45 #include "puffs_priv.h"
  46
  47 /*
  48  * Read a frame from the upstream provider.  First read the frame
  49  * length and after this read the actual contents.  Yes, optimize
  50  * me some day.
  51  */
  52 /*ARGSUSED*/
  53 int
  54 puffs__fsframe_read(struct puffs_usermount *pu, struct puffs_framebuf *pb,
  55         int fd, int *done)
  56 {
  57         struct putter_hdr phdr;
  58         void *win;
  59         size_t howmuch, winlen, curoff;
  60         ssize_t n;
  61         int lenstate;
  62
  63         /* How much to read? */
  64  the_next_level:
  65         curoff = puffs_framebuf_telloff(pb);
  66         if (curoff < sizeof(struct putter_hdr)) {
  67                 howmuch = sizeof(struct putter_hdr) - curoff;
  68                 lenstate = 1;
  69         } else {
  70                 puffs_framebuf_getdata_atoff(pb, 0, &phdr, sizeof(phdr));
  71                 /*LINTED*/
  72                 howmuch = phdr.pth_framelen - curoff;
  73                 lenstate = 0;
  74         }
  75
  76         if (puffs_framebuf_reserve_space(pb, howmuch) == -1)
  77                 return errno;
  78
  79         /* Read contents */
  80         while (howmuch) {
  81                 winlen = howmuch;
  82                 curoff = puffs_framebuf_telloff(pb);
  83                 if (puffs_framebuf_getwindow(pb, curoff, &win, &winlen) == -1)
  84                         return errno;
  85                 n = read(fd, win, winlen);
  86                 switch (n) {
  87                 case 0:
  88                         return ECONNRESET;
  89                 case -1:
  90                         if (errno == EAGAIN)
  91                                 return 0;
  92                         return errno;
  93                 default:
  94                         howmuch -= n;
  95                         puffs_framebuf_seekset(pb, curoff + n);
  96                         break;
  97                 }
  98         }
  99
 100         if (lenstate)
 101                 goto the_next_level;
 102
 103         puffs_framebuf_seekset(pb, 0);
 104         *done = 1;
 105         return 0;
 106 }
 107
 108 /*
 109  * Write a frame upstream
 110  */
 111 /*ARGSUSED*/
 112 int
 113 puffs__fsframe_write(struct puffs_usermount *pu, struct puffs_framebuf *pb,
 114         int fd, int *done)
 115 {
 116         void *win;
 117         uint64_t flen;
 118         size_t winlen, howmuch, curoff;
 119         ssize_t n;
 120         int rv;
 121
 122         /*
 123          * Finalize it if we haven't written anything yet (or we're still
 124          * attempting to write the first byte)
 125          *
 126          * XXX: this shouldn't be here
 127          */
 128         if (puffs_framebuf_telloff(pb) == 0) {
 129                 struct puffs_req *preq;
 130
 131                 winlen = sizeof(struct puffs_req);
 132                 rv = puffs_framebuf_getwindow(pb, 0, (void *)&preq, &winlen);
 133                 if (rv == -1)
 134                         return errno;
 135                 preq->preq_pth.pth_framelen = flen = preq->preq_buflen;
 136         } else {
 137                 struct putter_hdr phdr;
 138
 139                 puffs_framebuf_getdata_atoff(pb, 0, &phdr, sizeof(phdr));
 140                 flen = phdr.pth_framelen;
 141         }
 142
 143         /*
 144          * Then write it.  Chances are if we are talking to the kernel it'll
 145          * just shlosh in all at once, but if we're e.g. talking to the
 146          * network it might take a few tries.
 147          */
 148         /*LINTED*/
 149         howmuch = flen - puffs_framebuf_telloff(pb);
 150
 151         while (howmuch) {
 152                 winlen = howmuch;
 153                 curoff = puffs_framebuf_telloff(pb);
 154                 if (puffs_framebuf_getwindow(pb, curoff, &win, &winlen) == -1)
 155                         return errno;
 156
 157                 /*
 158                  * XXX: we know from the framebuf implementation that we
 159                  * will always managed to map the entire window.  But if
 160                  * that changes, this will catch it.  Then we can do stuff
 161                  * iov stuff instead.
 162                  */
 163                 assert(winlen == howmuch);
 164
 165                 /* XXX: want NOSIGNAL if writing to a pipe */
 166 #if 0
 167                 n = send(fd, win, winlen, MSG_NOSIGNAL);
 168 #else
 169                 n = write(fd, win, winlen);
 170 #endif
 171                 switch (n) {
 172                 case 0:
 173                         return ECONNRESET;
 174                 case -1:
 175                         if (errno == EAGAIN)
 176                                 return 0;
 177                         return errno;
 178                 default:
 179                         howmuch -= n;
 180                         puffs_framebuf_seekset(pb, curoff + n);
 181                         break;
 182                 }
 183         }
 184
 185         *done = 1;
 186         return 0;
 187 }
 188
 189 /*
 190  * Compare if "pb1" is a response to a previously sent frame pb2.
 191  * More often than not "pb1" is not a response to anything but
 192  * rather a fresh request from the kernel.
 193  */
 194 /*ARGSUSED*/
 195 int
 196 puffs__fsframe_cmp(struct puffs_usermount *pu,
 197         struct puffs_framebuf *pb1, struct puffs_framebuf *pb2, int *notresp)
 198 {
 199         struct puffs_req *preq1, *preq2;
 200         size_t winlen;
 201         int rv;
 202
 203         /* map incoming preq */
 204         winlen = sizeof(struct puffs_req);
 205         rv = puffs_framebuf_getwindow(pb1, 0, (void *)&preq1, &winlen);
 206         assert(rv == 0); /* frames are always at least puffs_req in size */
 207         assert(winlen == sizeof(struct puffs_req));
 208
 209         /*
 210          * Check if this is not a response in this slot.  That's the
 211          * likely case.
 212          */
 213         if ((preq1->preq_opclass & PUFFSOPFLAG_ISRESPONSE) == 0) {
 214                 *notresp = 1;
 215                 return 0;
 216         }
 217
 218         /* map second preq */
 219         winlen = sizeof(struct puffs_req);
 220         rv = puffs_framebuf_getwindow(pb2, 0, (void *)&preq2, &winlen);
 221         assert(rv == 0); /* frames are always at least puffs_req in size */
 222         assert(winlen == sizeof(struct puffs_req));
 223
 224         /* then compare: resid equal? */
 225         return preq1->preq_id != preq2->preq_id;
 226 }
 227
 228 void
 229 puffs__fsframe_gotframe(struct puffs_usermount *pu, struct puffs_framebuf *pb)
 230 {
 231
 232         puffs_framebuf_seekset(pb, 0);
 233         puffs__ml_dispatch(pu, pb);
 234 }