sbin/mount_portal/activate.c

   1 /*
   2  * Copyright (c) 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  * All rights reserved.
   5  *
   6  * This code is derived from software donated to Berkeley by
   7  * Jan-Simon Pendry.
   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  * 3. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      @(#)activate.c  8.3 (Berkeley) 4/28/95
  34  *
  35  * $FreeBSD: src/sbin/mount_portal/activate.c,v 1.7 1999/08/28 00:13:35 peter Exp $
  36  * $DragonFly: src/sbin/mount_portal/activate.c,v 1.6 2007/05/18 17:05:12 dillon Exp $
  37  */
  38
  39 #include <errno.h>
  40 #include <string.h>
  41 #include <unistd.h>
  42 #include <sys/types.h>
  43 #include <sys/param.h>
  44 #include <sys/socket.h>
  45 #include <sys/syslog.h>
  46 #include <sys/uio.h>
  47
  48 #include "portald.h"
  49
  50 /*
  51  * Scan the providers list and call the
  52  * appropriate function.
  53  */
  54 static int
  55 activate_argv(struct portal_cred *pcr, char *key, char **v, int so, int *fdp)
  56 {
  57         provider *pr;
  58
  59         for (pr = providers; pr->pr_match; pr++)
  60                 if (strcmp(v[0], pr->pr_match) == 0)
  61                         return ((*pr->pr_func)(pcr, key, v, so, fdp));
  62
  63         return (ENOENT);
  64 }
  65
  66 static int
  67 get_request(int so, struct portal_cred *pcr, char *key, int klen)
  68 {
  69         struct iovec iov[2];
  70         struct msghdr msg;
  71         int n;
  72
  73         iov[0].iov_base = (caddr_t) pcr;
  74         iov[0].iov_len = sizeof(*pcr);
  75         iov[1].iov_base = key;
  76         iov[1].iov_len = klen;
  77
  78         memset(&msg, 0, sizeof(msg));
  79         msg.msg_iov = iov;
  80         msg.msg_iovlen = 2;
  81
  82         n = recvmsg(so, &msg, 0);
  83         if (n < 0)
  84                 return (errno);
  85
  86         if ((size_t)n <= sizeof(*pcr))
  87                 return (EINVAL);
  88
  89         n -= sizeof(*pcr);
  90         key[n] = '\0';
  91
  92         return (0);
  93 }
  94
  95 static void
  96 send_reply(int so, int fd, int error)
  97 {
  98         int n;
  99         struct iovec iov;
 100         struct msghdr msg;
 101         struct {
 102                 struct cmsghdr cmsg;
 103                 int fd;
 104         } ctl;
 105
 106         /*
 107          * Line up error code.  Don't worry about byte ordering
 108          * because we must be sending to the local machine.
 109          */
 110         iov.iov_base = (caddr_t) &error;
 111         iov.iov_len = sizeof(error);
 112
 113         /*
 114          * Build a msghdr
 115          */
 116         memset(&msg, 0, sizeof(msg));
 117         msg.msg_iov = &iov;
 118         msg.msg_iovlen = 1;
 119
 120         /*
 121          * If there is a file descriptor to send then
 122          * construct a suitable rights control message.
 123          */
 124         if (fd >= 0) {
 125                 ctl.fd = fd;
 126                 ctl.cmsg.cmsg_len = sizeof(ctl);
 127                 ctl.cmsg.cmsg_level = SOL_SOCKET;
 128                 ctl.cmsg.cmsg_type = SCM_RIGHTS;
 129                 msg.msg_control = (caddr_t) &ctl;
 130                 msg.msg_controllen = ctl.cmsg.cmsg_len;
 131         }
 132
 133         /*
 134          * Send to kernel...
 135          */
 136         if ((n = sendmsg(so, &msg, 0)) < 0)
 137                 syslog(LOG_ERR, "send: %s", strerror(errno));
 138 #ifdef DEBUG
 139         fprintf(stderr, "sent %d bytes\n", n);
 140 #endif
 141         sleep(1);       /*XXX*/
 142 #ifdef notdef
 143         if (shutdown(so, SHUT_RDWR) < 0)
 144                 syslog(LOG_ERR, "shutdown: %s", strerror(errno));
 145 #endif
 146         /*
 147          * Throw away the open file descriptor
 148          */
 149         close(fd);
 150 }
 151
 152 void
 153 activate(qelem *q, int so)
 154 {
 155         struct portal_cred pcred;
 156         char key[MAXPATHLEN+1];
 157         int error;
 158         char **v;
 159         int fd = -1;
 160
 161         /*
 162          * Read the key from the socket
 163          */
 164         error = get_request(so, &pcred, key, sizeof(key));
 165         if (error) {
 166                 syslog(LOG_ERR, "activate: recvmsg: %s", strerror(error));
 167                 goto drop;
 168         }
 169
 170 #ifdef DEBUG
 171         fprintf(stderr, "lookup key %s\n", key);
 172 #endif
 173
 174         /*
 175          * Find a match in the configuration file
 176          */
 177         v = conf_match(q, key);
 178
 179         /*
 180          * If a match existed, then find an appropriate portal
 181          * otherwise simply return ENOENT.
 182          */
 183         if (v) {
 184                 error = activate_argv(&pcred, key, v, so, &fd);
 185                 if (error)
 186                         fd = -1;
 187                 else if (fd < 0)
 188                         error = -1;
 189         } else {
 190                 error = ENOENT;
 191         }
 192
 193         if (error >= 0)
 194                 send_reply(so, fd, error);
 195
 196 drop:;
 197         close(so);
 198 }