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 /*
  36  * Are there already sockets configured? If not, then it is safe to try to
  37  * open some and pass them through.
  38  *
  39  * Note: If the user explicitly asked for 'udp', then we should probably check
  40  * if that is open, and should open it if not. However we don't yet. All
  41  * sockets have to be opened when the first daemon is started.
  42  */
  43 int
  44 nfssvc_inuse(void)
  45 {
  46         int fd, n;
  47
  48         fd = open(NFSD_PORTS_FILE, O_RDONLY);
  49
  50         /* problem opening file, assume that nothing is configured */
  51         if (fd < 0)
  52                 return 0;
  53
  54         n = read(fd, buf, sizeof(buf));
  55         close(fd);
  56
  57         xlog(D_GENERAL, "knfsd is currently %s", (n > 0) ? "up" : "down");
  58
  59         return (n > 0);
  60 }
  61
  62 static void
  63 nfssvc_setfds(int port, unsigned int ctlbits, char *haddr)
  64 {
  65         int fd, on=1;
  66         int udpfd = -1, tcpfd = -1;
  67         struct sockaddr_in sin;
  68
  69         if (nfssvc_inuse())
  70                 return;
  71
  72         fd = open(NFSD_PORTS_FILE, O_WRONLY);
  73         if (fd < 0)
  74                 return;
  75         sin.sin_family = AF_INET;
  76         sin.sin_port   = htons(port);
  77         sin.sin_addr.s_addr =  inet_addr(haddr);
  78
  79         if (NFSCTL_UDPISSET(ctlbits)) {
  80                 udpfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
  81                 if (udpfd < 0) {
  82                         xlog(L_ERROR, "unable to create UDP socket: "
  83                                 "errno %d (%m)", errno);
  84                         exit(1);
  85                 }
  86                 if (bind(udpfd, (struct  sockaddr  *)&sin, sizeof(sin)) < 0){
  87                         xlog(L_ERROR, "unable to bind UDP socket: "
  88                                 "errno %d (%m)", errno);
  89                         exit(1);
  90                 }
  91         }
  92
  93         if (NFSCTL_TCPISSET(ctlbits)) {
  94                 tcpfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  95                 if (tcpfd < 0) {
  96                         xlog(L_ERROR, "unable to create TCP socket: "
  97                                 "errno %d (%m)", errno);
  98                         exit(1);
  99                 }
 100                 if (setsockopt(tcpfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0) {
 101                         xlog(L_ERROR, "unable to set SO_REUSEADDR: "
 102                                 "errno %d (%m)", errno);
 103                         exit(1);
 104                 }
 105                 if (bind(tcpfd, (struct  sockaddr  *)&sin, sizeof(sin)) < 0){
 106                         xlog(L_ERROR, "unable to bind TCP socket: "
 107                                 "errno %d (%m)", errno);
 108                         exit(1);
 109                 }
 110                 if (listen(tcpfd, 64) < 0){
 111                         xlog(L_ERROR, "unable to create listening socket: "
 112                                 "errno %d (%m)", errno);
 113                         exit(1);
 114                 }
 115         }
 116         if (udpfd >= 0) {
 117                 snprintf(buf, sizeof(buf), "%d\n", udpfd);
 118                 if (write(fd, buf, strlen(buf)) != strlen(buf)) {
 119                         xlog(L_ERROR,
 120                                "writing fds to kernel failed: errno %d (%m)",
 121                                errno);
 122                 }
 123                 close(fd);
 124                 fd = -1;
 125         }
 126         if (tcpfd >= 0) {
 127                 if (fd < 0)
 128                         fd = open(NFSD_PORTS_FILE, O_WRONLY);
 129                 snprintf(buf, sizeof(buf), "%d\n", tcpfd);
 130                 if (write(fd, buf, strlen(buf)) != strlen(buf)) {
 131                         xlog(L_ERROR,
 132                                "writing fds to kernel failed: errno %d (%m)",
 133                                errno);
 134                 }
 135         }
 136         close(fd);
 137
 138         return;
 139 }
 140 static void
 141 nfssvc_versbits(unsigned int ctlbits, int minorvers4)
 142 {
 143         int fd, n, off;
 144         char *ptr;
 145
 146         ptr = buf;
 147         off = 0;
 148         fd = open(NFSD_VERS_FILE, O_WRONLY);
 149         if (fd < 0)
 150                 return;
 151
 152         for (n = NFSD_MINVERS; n <= NFSD_MAXVERS; n++) {
 153                 if (NFSCTL_VERISSET(ctlbits, n))
 154                     off += snprintf(ptr+off, sizeof(buf) - off, "+%d ", n);
 155                 else
 156                     off += snprintf(ptr+off, sizeof(buf) - off, "-%d ", n);
 157         }
 158         n = minorvers4 >= 0 ? minorvers4 : -minorvers4;
 159         if (n >= NFSD_MINMINORVERS4 && n <= NFSD_MAXMINORVERS4)
 160                     off += snprintf(ptr+off, sizeof(buf) - off, "%c4.%d",
 161                                     minorvers4 > 0 ? '+' : '-',
 162                                     n);
 163         xlog(D_GENERAL, "Writing version string to kernel: %s", buf);
 164         snprintf(ptr+off, sizeof(buf) - off, "\n");
 165         if (write(fd, buf, strlen(buf)) != strlen(buf))
 166                 xlog(L_ERROR, "Setting version failed: errno %d (%m)", errno);
 167
 168         close(fd);
 169
 170         return;
 171 }
 172 int
 173 nfssvc(int port, int nrservs, unsigned int versbits, int minorvers4,
 174         unsigned protobits, char *haddr)
 175 {
 176         struct nfsctl_arg       arg;
 177         int fd;
 178
 179         /* Note: must set versions before fds so that
 180          * the ports get registered with portmap against correct
 181          * versions
 182          */
 183         nfssvc_versbits(versbits, minorvers4);
 184         nfssvc_setfds(port, protobits, haddr);
 185
 186         fd = open(NFSD_THREAD_FILE, O_WRONLY);
 187         if (fd < 0)
 188                 fd = open("/proc/fs/nfs/threads", O_WRONLY);
 189         if (fd >= 0) {
 190                 /* 2.5+ kernel with nfsd filesystem mounted.
 191                  * Just write the number in.
 192                  * Cannot handle port number yet, but does anyone care?
 193                  */
 194                 int n;
 195                 snprintf(buf, sizeof(buf), "%d\n", nrservs);
 196                 n = write(fd, buf, strlen(buf));
 197                 close(fd);
 198                 if (n != strlen(buf))
 199                         return -1;
 200                 else
 201                         return 0;
 202         }
 203
 204         arg.ca_version = NFSCTL_VERSION;
 205         arg.ca_svc.svc_nthreads = nrservs;
 206         arg.ca_svc.svc_port = port;
 207         return nfsctl(NFSCTL_SVC, &arg, NULL);
 208 }