sbin/mount_portal/activate.c

   1 /*      $NetBSD: activate.c,v 1.14 2007/07/02 18:07:44 pooka Exp $      */
   2
   3 /*
   4  * Copyright (c) 1992, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software donated to Berkeley by
   8  * Jan-Simon Pendry.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      from: Id: activate.c,v 1.2 1992/05/27 07:09:27 jsp Exp
  35  *      @(#)activate.c  8.3 (Berkeley) 4/28/95
  36  */
  37
  38 #include <sys/cdefs.h>
  39 #ifndef lint
  40 __RCSID("$NetBSD: activate.c,v 1.14 2007/07/02 18:07:44 pooka Exp $");
  41 #endif /* not lint */
  42
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <unistd.h>
  46 #include <string.h>
  47 #include <errno.h>
  48 #include <signal.h>
  49 #include <sys/types.h>
  50 #include <sys/param.h>
  51 #include <sys/socket.h>
  52 #include <sys/un.h>
  53 #include <sys/syslog.h>
  54 #include <sys/uio.h>
  55
  56 #include "portald.h"
  57
  58 static  int     get_request(int, struct portal_cred *, char *, size_t);
  59 static  void    send_reply(int, int, int);
  60
  61 /*
  62  * Scan the providers list and call the
  63  * appropriate function.
  64  */
  65 int
  66 activate_argv(struct portal_cred *pcr, char *key, char **v, int *fdp)
  67 {
  68         provider *pr;
  69
  70         for (pr = providers; pr->pr_match; pr++)
  71                 if (strcmp(v[0], pr->pr_match) == 0)
  72                         return ((*pr->pr_func)(pcr, key, v, fdp));
  73
  74         return (ENOENT);
  75 }
  76
  77 static int
  78 get_request(int so, struct portal_cred *pcr, char *key, size_t klen)
  79 {
  80         struct iovec iov[2];
  81         struct msghdr msg;
  82         ssize_t n;
  83
  84         iov[0].iov_base = (caddr_t) pcr;
  85         iov[0].iov_len = sizeof(*pcr);
  86         iov[1].iov_base = key;
  87         iov[1].iov_len = klen;
  88
  89         memset(&msg, 0, sizeof(msg));
  90         msg.msg_iov = iov;
  91         msg.msg_iovlen = 2;
  92
  93         n = recvmsg(so, &msg, 0);
  94         if (n < 0)
  95                 return (errno);
  96
  97         if (n <= (ssize_t)sizeof(*pcr))
  98                 return (EINVAL);
  99
 100         n -= sizeof(*pcr);
 101         key[n] = '\0';
 102
 103         return (0);
 104 }
 105
 106 static void
 107 send_reply(int so, int fd, int error)
 108 {
 109         int n;
 110         struct iovec iov;
 111         struct msghdr msg;
 112         void *ctl = NULL;
 113         struct cmsghdr *cmsg;
 114         int *files;
 115         socklen_t cmsgsize;
 116
 117         /*
 118          * Line up error code.  Don't worry about byte ordering
 119          * because we must be sending to the local machine.
 120          */
 121         iov.iov_base = (caddr_t) &error;
 122         iov.iov_len = sizeof(error);
 123
 124         /*
 125          * Build a msghdr
 126          */
 127         memset(&msg, 0, sizeof(msg));
 128         msg.msg_iov = &iov;
 129         msg.msg_iovlen = 1;
 130
 131         /*
 132          * If there is a file descriptor to send then
 133          * construct a suitable rights control message.
 134          */
 135         if (fd >= 0) {
 136                 cmsgsize = CMSG_LEN(sizeof(*files));
 137
 138                 ctl = malloc(cmsgsize);
 139                 if (ctl == NULL) {
 140                         syslog(LOG_WARNING, "malloc control message: %m");
 141                         return;
 142                 }
 143                 memset(ctl, 0, cmsgsize);
 144
 145                 cmsg = (struct cmsghdr *) ctl;
 146                 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
 147                 cmsg->cmsg_level = SOL_SOCKET;
 148                 cmsg->cmsg_type = SCM_RIGHTS;
 149
 150                 files = (int *)CMSG_DATA(cmsg);
 151                 files[0] = fd;
 152
 153                 msg.msg_control = ctl;
 154                 msg.msg_controllen = cmsgsize;
 155         }
 156
 157         /*
 158          * Send to kernel...
 159          */
 160         if ((n = sendmsg(so, &msg, MSG_EOR)) < 0)
 161                 syslog(LOG_WARNING, "send: %m");
 162 #ifdef DEBUG
 163         fprintf(stderr, "sent %d bytes\n", n);
 164 #endif
 165         sleep(1);       /*XXX*/
 166 #ifdef notdef
 167         if (shutdown(so, 2) < 0)
 168                 syslog(LOG_WARNING, "shutdown: %m");
 169 #endif
 170         /*
 171          * Throw away the open file descriptor and control
 172          * message buffer.
 173          */
 174         if (fd >= 0)
 175                 (void) close(fd);
 176         if (ctl != NULL)
 177                 free(ctl);
 178 }
 179
 180 void
 181 activate(qelem *q, int so)
 182 {
 183         struct portal_cred pcred;
 184         char key[MAXPATHLEN+1];
 185         int error;
 186         char **v;
 187         int fd = -1;
 188
 189         /*
 190          * Read the key from the socket
 191          */
 192         error = get_request(so, &pcred, key, sizeof(key));
 193         if (error) {
 194                 syslog(LOG_WARNING, "activate: recvmsg: %m");
 195                 goto drop;
 196         }
 197
 198 #ifdef DEBUG
 199         fprintf(stderr, "lookup key %s\n", key);
 200 #endif
 201
 202         /*
 203          * Find a match in the configuration file
 204          */
 205         v = conf_match(q, key);
 206
 207         /*
 208          * If a match existed, then find an appropriate portal
 209          * otherwise simply return ENOENT.
 210          */
 211         if (v) {
 212                 error = activate_argv(&pcred, key, v, &fd);
 213                 if (error)
 214                         fd = -1;
 215                 else if (fd < 0)
 216                         error = -1;
 217         } else
 218                 error = ENOENT;
 219
 220         if (error >= 0)
 221                 send_reply(so, fd, error);
 222
 223 drop:;
 224         close(so);
 225 }