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      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 #include <dev/putter/putter.h>
     42 
     43 #include <assert.h>
     44 #include <errno.h>
     45 #include <puffs.h>
     46 #include <stdio.h>
     47 #include <stdlib.h>
     48 #include <unistd.h>
     49 
     50 #include "puffs_priv.h"
     51 
     52 /*
     53  * Read a frame from the upstream provider.  First read the frame
     54  * length and after this read the actual contents.  Yes, optimize
     55  * me some day.
     56  */
     57 /*ARGSUSED*/
     58 int
     59 puffs__fsframe_read(struct puffs_usermount *pu, struct puffs_framebuf *pb,
     60 	int fd, int *done)
     61 {
     62 	struct putter_hdr phdr;
     63 	void *win;
     64 	size_t howmuch, winlen, curoff;
     65 	ssize_t n;
     66 	int lenstate;
     67 
     68 	/* How much to read? */
     69  the_next_level:
     70 	curoff = puffs_framebuf_telloff(pb);
     71 	if (curoff < sizeof(struct putter_hdr)) {
     72 		howmuch = sizeof(struct putter_hdr) - curoff;
     73 		lenstate = 1;
     74 	} else {
     75 		puffs_framebuf_getdata_atoff(pb, 0, &phdr, sizeof(phdr));
     76 		/*LINTED*/
     77 		howmuch = phdr.pth_framelen - curoff;
     78 		lenstate = 0;
     79 	}
     80 
     81 	if (puffs_framebuf_reserve_space(pb, howmuch) == -1)
     82 		return errno;
     83 
     84 	/* Read contents */
     85 	while (howmuch) {
     86 		winlen = howmuch;
     87 		curoff = puffs_framebuf_telloff(pb);
     88 		if (puffs_framebuf_getwindow(pb, curoff, &win, &winlen) == -1)
     89 			return errno;
     90 		n = read(fd, win, winlen);
     91 		switch (n) {
     92 		case 0:
     93 			return ECONNRESET;
     94 		case -1:
     95 			if (errno == EAGAIN)
     96 				return 0;
     97 			return errno;
     98 		default:
     99 			howmuch -= n;
    100 			puffs_framebuf_seekset(pb, curoff + n);
    101 			break;
    102 		}
    103 	}
    104 
    105 	if (lenstate)
    106 		goto the_next_level;
    107 
    108 	puffs_framebuf_seekset(pb, 0);
    109 	*done = 1;
    110 	return 0;
    111 }
    112 
    113 /*
    114  * Write a frame upstream
    115  */
    116 /*ARGSUSED*/
    117 int
    118 puffs__fsframe_write(struct puffs_usermount *pu, struct puffs_framebuf *pb,
    119 	int fd, int *done)
    120 {
    121 	void *win;
    122 	uint64_t flen;
    123 	size_t winlen, howmuch, curoff;
    124 	ssize_t n;
    125 	int rv;
    126 
    127 	/*
    128 	 * Finalize it if we haven't written anything yet (or we're still
    129 	 * attempting to write the first byte)
    130 	 *
    131 	 * XXX: this shouldn't be here
    132 	 */
    133 	if (puffs_framebuf_telloff(pb) == 0) {
    134 		struct puffs_req *preq;
    135 
    136 		winlen = sizeof(struct puffs_req);
    137 		rv = puffs_framebuf_getwindow(pb, 0, (void *)&preq, &winlen);
    138 		if (rv == -1)
    139 			return errno;
    140 		preq->preq_pth.pth_framelen = flen = preq->preq_buflen;
    141 	} else {
    142 		struct putter_hdr phdr;
    143 
    144 		puffs_framebuf_getdata_atoff(pb, 0, &phdr, sizeof(phdr));
    145 		flen = phdr.pth_framelen;
    146 	}
    147 
    148 	/*
    149 	 * Then write it.  Chances are if we are talking to the kernel it'll
    150 	 * just shlosh in all at once, but if we're e.g. talking to the
    151 	 * network it might take a few tries.
    152 	 */
    153 	/*LINTED*/
    154 	howmuch = flen - puffs_framebuf_telloff(pb);
    155 
    156 	while (howmuch) {
    157 		winlen = howmuch;
    158 		curoff = puffs_framebuf_telloff(pb);
    159 		if (puffs_framebuf_getwindow(pb, curoff, &win, &winlen) == -1)
    160 			return errno;
    161 
    162 		/*
    163 		 * XXX: we know from the framebuf implementation that we
    164 		 * will always managed to map the entire window.  But if
    165 		 * that changes, this will catch it.  Then we can do stuff
    166 		 * iov stuff instead.
    167 		 */
    168 		assert(winlen == howmuch);
    169 
    170 		/* XXX: want NOSIGNAL if writing to a pipe */
    171 #if 0
    172 		n = send(fd, win, winlen, MSG_NOSIGNAL);
    173 #else
    174 		n = write(fd, win, winlen);
    175 #endif
    176 		switch (n) {
    177 		case 0:
    178 			return ECONNRESET;
    179 		case -1:
    180 			if (errno == EAGAIN)
    181 				return 0;
    182 			return errno;
    183 		default:
    184 			howmuch -= n;
    185 			puffs_framebuf_seekset(pb, curoff + n);
    186 			break;
    187 		}
    188 	}
    189 
    190 	*done = 1;
    191 	return 0;
    192 }
    193 
    194 /*
    195  * Compare if "pb1" is a response to a previously sent frame pb2.
    196  * More often than not "pb1" is not a response to anything but
    197  * rather a fresh request from the kernel.
    198  */
    199 /*ARGSUSED*/
    200 int
    201 puffs__fsframe_cmp(struct puffs_usermount *pu,
    202 	struct puffs_framebuf *pb1, struct puffs_framebuf *pb2, int *notresp)
    203 {
    204 	struct puffs_req *preq1, *preq2;
    205 	size_t winlen;
    206 	int rv;
    207 
    208 	/* map incoming preq */
    209 	winlen = sizeof(struct puffs_req);
    210 	rv = puffs_framebuf_getwindow(pb1, 0, (void *)&preq1, &winlen);
    211 	assert(rv == 0); /* frames are always at least puffs_req in size */
    212 	assert(winlen == sizeof(struct puffs_req));
    213 
    214 	/*
    215 	 * Check if this is not a response in this slot.  That's the
    216 	 * likely case.
    217 	 */
    218 	if ((preq1->preq_opclass & PUFFSOPFLAG_ISRESPONSE) == 0) {
    219 		*notresp = 1;
    220 		return 0;
    221 	}
    222 
    223 	/* map second preq */
    224 	winlen = sizeof(struct puffs_req);
    225 	rv = puffs_framebuf_getwindow(pb2, 0, (void *)&preq2, &winlen);
    226 	assert(rv == 0); /* frames are always at least puffs_req in size */
    227 	assert(winlen == sizeof(struct puffs_req));
    228 
    229 	/* then compare: resid equal? */
    230 	return preq1->preq_id != preq2->preq_id;
    231 }
    232 
    233 void
    234 puffs__fsframe_gotframe(struct puffs_usermount *pu, struct puffs_framebuf *pb)
    235 {
    236 
    237 	puffs_framebuf_seekset(pb, 0);
    238 	puffs__ml_dispatch(pu, pb);
    239 }
    240