utils/nfsd/nfssvc.c

   1 /*
   2  * utils/nfsd/nfssvc.c
   3  *
   4  * Run an NFS daemon.
   5  *
   6  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   7  */
   8
   9 #ifdef HAVE_CONFIG_H
  10 #include <config.h>
  11 #endif
  12
  13 #include <sys/socket.h>
  14 #include <netinet/in.h>
  15 #include <arpa/inet.h>
  16 #include <unistd.h>
  17 #include <fcntl.h>
  18 #include <errno.h>
  19
  20 #include "nfslib.h"
  21 #include "xlog.h"
  22
  23 #define NFSD_PORTS_FILE     "/proc/fs/nfsd/portlist"
  24 #define NFSD_VERS_FILE    "/proc/fs/nfsd/versions"
  25 #define NFSD_THREAD_FILE  "/proc/fs/nfsd/threads"
  26
  27 /*
  28  * declaring a common static scratch buffer here keeps us from having to
  29  * continually thrash the stack. The value of 128 bytes here is really just a
  30  * SWAG and can be increased if necessary. It ought to be enough for the
  31  * routines below however.
  32  */
  33 char buf[128];
  34
  35 static void
  36 nfssvc_setfds(int port, unsigned int ctlbits, char *haddr)
  37 {
  38         int fd, n, on=1;
  39         int udpfd = -1, tcpfd = -1;
  40         struct sockaddr_in sin;
  41
  42         fd = open(NFSD_PORTS_FILE, O_RDONLY);
  43         if (fd < 0)
  44                 return;
  45         n = read(fd, buf, sizeof(buf));
  46         close(fd);
  47         if (n != 0)
  48                 return;
  49         /* there are no ports currently open, so it is safe to
  50          * try to open some and pass them through.
  51          * Note: If the user explicitly asked for 'udp', then
  52          * we should probably check if that is open, and should
  53          * open it if not.  However we don't yet.  All sockets
  54          * have to be opened when the first daemon is started.
  55          */
  56         fd = open(NFSD_PORTS_FILE, O_WRONLY);
  57         if (fd < 0)
  58                 return;
  59         sin.sin_family = AF_INET;
  60         sin.sin_port   = htons(port);
  61         sin.sin_addr.s_addr =  inet_addr(haddr);
  62
  63         if (NFSCTL_UDPISSET(ctlbits)) {
  64                 udpfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
  65                 if (udpfd < 0) {
  66                         xlog(L_ERROR, "unable to create UDP socket: "
  67                                 "errno %d (%m)", errno);
  68                         exit(1);
  69                 }
  70                 if (bind(udpfd, (struct  sockaddr  *)&sin, sizeof(sin)) < 0){
  71                         xlog(L_ERROR, "unable to bind UDP socket: "
  72                                 "errno %d (%m)", errno);
  73                         exit(1);
  74                 }
  75         }
  76
  77         if (NFSCTL_TCPISSET(ctlbits)) {
  78                 tcpfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  79                 if (tcpfd < 0) {
  80                         xlog(L_ERROR, "unable to create TCP socket: "
  81                                 "errno %d (%m)", errno);
  82                         exit(1);
  83                 }
  84                 if (setsockopt(tcpfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0) {
  85                         xlog(L_ERROR, "unable to set SO_REUSEADDR: "
  86                                 "errno %d (%m)", errno);
  87                         exit(1);
  88                 }
  89                 if (bind(tcpfd, (struct  sockaddr  *)&sin, sizeof(sin)) < 0){
  90                         xlog(L_ERROR, "unable to bind TCP socket: "
  91                                 "errno %d (%m)", errno);
  92                         exit(1);
  93                 }
  94                 if (listen(tcpfd, 64) < 0){
  95                         xlog(L_ERROR, "unable to create listening socket: "
  96                                 "errno %d (%m)", errno);
  97                         exit(1);
  98                 }
  99         }
 100         if (udpfd >= 0) {
 101                 snprintf(buf, sizeof(buf), "%d\n", udpfd);
 102                 if (write(fd, buf, strlen(buf)) != strlen(buf)) {
 103                         xlog(L_ERROR,
 104                                "writing fds to kernel failed: errno %d (%m)",
 105                                errno);
 106                 }
 107                 close(fd);
 108                 fd = -1;
 109         }
 110         if (tcpfd >= 0) {
 111                 if (fd < 0)
 112                         fd = open(NFSD_PORTS_FILE, O_WRONLY);
 113                 snprintf(buf, sizeof(buf), "%d\n", tcpfd);
 114                 if (write(fd, buf, strlen(buf)) != strlen(buf)) {
 115                         xlog(L_ERROR,
 116                                "writing fds to kernel failed: errno %d (%m)",
 117                                errno);
 118                 }
 119         }
 120         close(fd);
 121
 122         return;
 123 }
 124 static void
 125 nfssvc_versbits(unsigned int ctlbits, int minorvers4)
 126 {
 127         int fd, n, off;
 128         char *ptr;
 129
 130         ptr = buf;
 131         off = 0;
 132         fd = open(NFSD_VERS_FILE, O_WRONLY);
 133         if (fd < 0)
 134                 return;
 135
 136         for (n = NFSD_MINVERS; n <= NFSD_MAXVERS; n++) {
 137                 if (NFSCTL_VERISSET(ctlbits, n))
 138                     off += snprintf(ptr+off, sizeof(buf) - off, "+%d ", n);
 139                 else
 140                     off += snprintf(ptr+off, sizeof(buf) - off, "-%d ", n);
 141         }
 142         n = minorvers4 >= 0 ? minorvers4 : -minorvers4;
 143         if (n >= NFSD_MINMINORVERS4 && n <= NFSD_MAXMINORVERS4)
 144                     off += snprintf(ptr+off, sizeof(buf) - off, "%c4.%d",
 145                                     minorvers4 > 0 ? '+' : '-',
 146                                     n);
 147         xlog(D_GENERAL, "Writing version string to kernel: %s", buf);
 148         snprintf(ptr+off, sizeof(buf) - off, "\n");
 149         if (write(fd, buf, strlen(buf)) != strlen(buf))
 150                 xlog(L_ERROR, "Setting version failed: errno %d (%m)", errno);
 151
 152         close(fd);
 153
 154         return;
 155 }
 156 int
 157 nfssvc(int port, int nrservs, unsigned int versbits, int minorvers4,
 158         unsigned protobits, char *haddr)
 159 {
 160         struct nfsctl_arg       arg;
 161         int fd;
 162
 163         /* Note: must set versions before fds so that
 164          * the ports get registered with portmap against correct
 165          * versions
 166          */
 167         nfssvc_versbits(versbits, minorvers4);
 168         nfssvc_setfds(port, protobits, haddr);
 169
 170         fd = open(NFSD_THREAD_FILE, O_WRONLY);
 171         if (fd < 0)
 172                 fd = open("/proc/fs/nfs/threads", O_WRONLY);
 173         if (fd >= 0) {
 174                 /* 2.5+ kernel with nfsd filesystem mounted.
 175                  * Just write the number in.
 176                  * Cannot handle port number yet, but does anyone care?
 177                  */
 178                 int n;
 179                 snprintf(buf, sizeof(buf), "%d\n", nrservs);
 180                 n = write(fd, buf, strlen(buf));
 181                 close(fd);
 182                 if (n != strlen(buf))
 183                         return -1;
 184                 else
 185                         return 0;
 186         }
 187
 188         arg.ca_version = NFSCTL_VERSION;
 189         arg.ca_svc.svc_nthreads = nrservs;
 190         arg.ca_svc.svc_port = port;
 191         return nfsctl(NFSCTL_SVC, &arg, NULL);
 192 }