usr.sbin/puffs/mount_9p/subr.c

   1 /*      $NetBSD: subr.c,v 1.5 2007/05/16 09:57:21 pooka Exp $   */
   2
   3 /*
   4  * Copyright (c) 2007  Antti Kantee.  All Rights Reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
  16  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  18  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  21  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27
  28 #include <sys/cdefs.h>
  29 #ifndef lint
  30 __RCSID("$NetBSD: subr.c,v 1.5 2007/05/16 09:57:21 pooka Exp $");
  31 #endif /* !lint */
  32
  33 #include <sys/types.h>
  34
  35 #include <errno.h>
  36 #include <puffs.h>
  37 #include <stdlib.h>
  38 #include <util.h>
  39
  40 #include "ninepuffs.h"
  41 #include "nineproto.h"
  42
  43 void
  44 qid2vattr(struct vattr *vap, const struct qid9p *qid)
  45 {
  46
  47         vap->va_fileid = qid->qidpath;
  48         vap->va_gen = qid->qidvers;
  49         if (qid->qidtype & P9PROTO_QID_TYPE_DIR)
  50                 vap->va_type = VDIR;
  51         else
  52                 vap->va_type = VREG;
  53 }
  54
  55 static struct puffs_node *
  56 makep9pnode(struct puffs_usermount *pu, p9pfid_t fid)
  57 {
  58         struct p9pnode *p9n;
  59         struct puffs_node *pn;
  60
  61         p9n = emalloc(sizeof(struct p9pnode));
  62         memset(p9n, 0, sizeof(struct p9pnode));
  63         p9n->fid_base = fid;
  64         LIST_INIT(&p9n->dir_openlist);
  65
  66         pn = puffs_pn_new(pu, p9n);
  67         if (pn == NULL)
  68                 abort();
  69
  70         return pn;
  71 }
  72
  73 struct puffs_node *
  74 newp9pnode_va(struct puffs_usermount *pu, const struct vattr *va, p9pfid_t fid)
  75 {
  76         struct puffs_node *pn;
  77
  78         pn = makep9pnode(pu, fid);
  79         pn->pn_va = *va;
  80
  81         return pn;
  82 }
  83
  84 struct puffs_node *
  85 newp9pnode_qid(struct puffs_usermount *pu, const struct qid9p *qid,
  86         p9pfid_t fid)
  87 {
  88         struct puffs_node *pn;
  89
  90         pn = makep9pnode(pu, fid);
  91         puffs_vattr_null(&pn->pn_va);
  92         qid2vattr(&pn->pn_va, qid);
  93
  94         return pn;
  95 }
  96
  97 /*
  98  * search list of fids, or if none is found, walk a fid for a new one
  99  * and issue dummy readdirs until we get the result we want
 100  */
 101 int
 102 getdfwithoffset(struct puffs_usermount *pu, struct p9pnode *p9n, off_t wantoff,
 103         struct dirfid **rfid)
 104 {
 105         struct puffs_cc *pcc = puffs_cc_getcc(pu);
 106         struct puffs9p *p9p = puffs_getspecific(pu);
 107         struct puffs_framebuf *pb;
 108         struct dirfid *dfp = NULL;
 109         p9ptag_t tag = NEXTTAG(p9p);
 110         off_t curoff, advance;
 111         uint32_t count;
 112         int rv;
 113
 114         LIST_FOREACH(dfp, &p9n->dir_openlist, entries) {
 115                 if (dfp->seekoff == wantoff) {
 116                         LIST_REMOVE(dfp, entries);
 117                         *rfid = dfp;
 118                         return 0;
 119                 }
 120         }
 121
 122         /* didn't get off easy?  damn, do manual labour */
 123         pb = p9pbuf_makeout();
 124         dfp = ecalloc(1, sizeof(struct dirfid));
 125         dfp->fid = NEXTFID(p9p);
 126         rv = proto_cc_open(pu, p9n->fid_base, dfp->fid, P9PROTO_OMODE_READ);
 127         if (rv)
 128                 goto out;
 129
 130         for (curoff = 0;;) {
 131                 advance = wantoff - curoff;
 132
 133                 tag = NEXTTAG(p9p);
 134                 p9pbuf_put_1(pb, P9PROTO_T_READ);
 135                 p9pbuf_put_2(pb, tag);
 136                 p9pbuf_put_4(pb, dfp->fid);
 137                 p9pbuf_put_8(pb, 0);
 138                 p9pbuf_put_4(pb, advance);
 139                 GETRESPONSE(pb);
 140
 141                 if (p9pbuf_get_type(pb) != P9PROTO_R_READ) {
 142                         rv = EPROTO;
 143                         goto out;
 144                 }
 145
 146                 /*
 147                  * Check how many bytes we got.  If we got the amount we
 148                  * wanted, we are at the correct position.  If we got
 149                  * zero bytes, either the directory doesn't "support" the
 150                  * seek offset we want (someone has probably inserted an
 151                  * entry meantime) or we at the end of directory.  Either
 152                  * way, let the upper layer deal with it.
 153                  */
 154                 p9pbuf_get_4(pb, &count);
 155                 curoff += count;
 156                 if (count == advance || count == 0)
 157                         break;
 158
 159                 p9pbuf_recycleout(pb);
 160         }
 161         puffs_framebuf_destroy(pb);
 162
 163         dfp->seekoff = curoff;
 164         *rfid = dfp;
 165         return 0;
 166
 167  out:
 168         puffs_framebuf_destroy(pb);
 169         free(dfp);
 170         return rv;
 171 }
 172
 173 void
 174 releasedf(struct puffs_usermount *pu, struct dirfid *dfp)
 175 {
 176
 177         proto_cc_clunkfid(pu, dfp->fid, 0);
 178         free(dfp);
 179 }
 180
 181 void
 182 storedf(struct p9pnode *p9n, struct dirfid *dfp)
 183 {
 184
 185         LIST_INSERT_HEAD(&p9n->dir_openlist, dfp, entries);
 186 }
 187
 188 void
 189 nukealldf(struct puffs_usermount *pu, struct p9pnode *p9n)
 190 {
 191         struct dirfid *dfp;
 192
 193         while ((dfp = LIST_FIRST(&p9n->dir_openlist)) != NULL) {
 194                 LIST_REMOVE(dfp, entries);
 195                 releasedf(pu, dfp);
 196         }
 197 }