lnet/lnet/lib-socket.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
   4  * Use is subject to license terms.
   5  *
   6  * Copyright (c) 2015, 2017, Intel Corporation.
   7  */
   8
   9 /* This file is part of Lustre, http://www.lustre.org/ */
  10
  11 #define DEBUG_SUBSYSTEM S_LNET
  12
  13 #include <linux/if.h>
  14 #include <linux/in.h>
  15 #include <linux/net.h>
  16 #include <net/addrconf.h>
  17 #include <net/ipv6.h>
  18 #include <linux/file.h>
  19 #include <linux/pagemap.h>
  20 /* For sys_open & sys_close */
  21 #include <linux/syscalls.h>
  22 #include <net/sock.h>
  23 #include <linux/inetdevice.h>
  24
  25 #include <libcfs/linux/linux-time.h>
  26 #include <libcfs/linux/linux-net.h>
  27 #include <libcfs/libcfs.h>
  28 #include <lnet/lib-lnet.h>
  29
  30 int
  31 lnet_sock_write(struct socket *sock, void *buffer, int nob, int timeout)
  32 {
  33         int rc;
  34         long jiffies_left = cfs_time_seconds(timeout);
  35         unsigned long then;
  36
  37         LASSERT(nob > 0);
  38         /* Caller may pass a zero timeout if she thinks the socket buffer is
  39          * empty enough to take the whole message immediately */
  40
  41         for (;;) {
  42                 struct kvec  iov = {
  43                         .iov_base = buffer,
  44                         .iov_len  = nob
  45                 };
  46                 struct msghdr msg = {
  47                         .msg_flags      = (timeout == 0) ? MSG_DONTWAIT : 0
  48                 };
  49
  50                 if (timeout != 0) {
  51                         struct sock *sk = sock->sk;
  52
  53                         /* Set send timeout to remaining time */
  54                         lock_sock(sk);
  55                         sk->sk_sndtimeo = jiffies_left;
  56                         release_sock(sk);
  57                 }
  58
  59                 then = jiffies;
  60                 rc = kernel_sendmsg(sock, &msg, &iov, 1, nob);
  61                 jiffies_left -= jiffies - then;
  62
  63                 if (rc == nob)
  64                         return 0;
  65
  66                 if (rc < 0)
  67                         return rc;
  68
  69                 if (rc == 0) {
  70                         CERROR("Unexpected zero rc\n");
  71                         return -ECONNABORTED;
  72                 }
  73
  74                 if (jiffies_left <= 0)
  75                         return -EAGAIN;
  76
  77                 buffer = ((char *)buffer) + rc;
  78                 nob -= rc;
  79         }
  80         return 0;
  81 }
  82 EXPORT_SYMBOL(lnet_sock_write);
  83
  84 int
  85 lnet_sock_read(struct socket *sock, void *buffer, int nob, int timeout)
  86 {
  87         int rc;
  88         long jiffies_left = cfs_time_seconds(timeout);
  89         unsigned long then;
  90
  91         LASSERT(nob > 0);
  92         LASSERT(jiffies_left > 0);
  93
  94         for (;;) {
  95                 struct kvec  iov = {
  96                         .iov_base = buffer,
  97                         .iov_len  = nob
  98                 };
  99                 struct msghdr msg = {
 100                         .msg_flags      = 0
 101                 };
 102                 struct sock *sk = sock->sk;
 103
 104                 /* Set receive timeout to remaining time */
 105                 lock_sock(sk);
 106                 sk->sk_rcvtimeo = jiffies_left;
 107                 release_sock(sk);
 108
 109                 then = jiffies;
 110                 rc = kernel_recvmsg(sock, &msg, &iov, 1, nob, 0);
 111                 jiffies_left -= jiffies - then;
 112
 113                 if (rc < 0)
 114                         return rc;
 115
 116                 if (rc == 0)
 117                         return -ECONNRESET;
 118
 119                 buffer = ((char *)buffer) + rc;
 120                 nob -= rc;
 121
 122                 if (nob == 0)
 123                         return 0;
 124
 125                 if (jiffies_left <= 0)
 126                         return -ETIMEDOUT;
 127         }
 128 }
 129 EXPORT_SYMBOL(lnet_sock_read);
 130
 131 int choose_ipv4_src(__u32 *ret, int interface, __u32 dst_ipaddr, struct net *ns)
 132 {
 133         struct net_device *dev;
 134         struct in_device *in_dev;
 135         int err;
 136         DECLARE_CONST_IN_IFADDR(ifa);
 137
 138         rcu_read_lock();
 139         dev = dev_get_by_index_rcu(ns, interface);
 140         err = -EINVAL;
 141         if (!dev || !(dev->flags & IFF_UP))
 142                 goto out;
 143         in_dev = __in_dev_get_rcu(dev);
 144         if (!in_dev)
 145                 goto out;
 146         err = -ENOENT;
 147         in_dev_for_each_ifa_rcu(ifa, in_dev) {
 148                 if (err ||
 149                     ((dst_ipaddr ^ ntohl(ifa->ifa_local))
 150                      & ntohl(ifa->ifa_mask)) == 0) {
 151                         /* This address at least as good as what we
 152                          * already have
 153                          */
 154                         *ret = ntohl(ifa->ifa_local);
 155                         err = 0;
 156                 }
 157         }
 158         endfor_ifa(in_dev);
 159 out:
 160         rcu_read_unlock();
 161         return err;
 162 }
 163 EXPORT_SYMBOL(choose_ipv4_src);
 164
 165 static struct socket *
 166 lnet_sock_create(int interface, struct sockaddr *remaddr,
 167                  int local_port, struct net *ns)
 168 {
 169         struct socket *sock;
 170         int rc;
 171         int family;
 172
 173         family = AF_INET6;
 174         if (remaddr)
 175                 family = remaddr->sa_family;
 176 retry:
 177 #ifdef HAVE_SOCK_CREATE_KERN_USE_NET
 178         rc = sock_create_kern(ns, family, SOCK_STREAM, 0, &sock);
 179 #else
 180         rc = sock_create_kern(family, SOCK_STREAM, 0, &sock);
 181 #endif
 182         if (rc == -EAFNOSUPPORT && family == AF_INET6 && !remaddr) {
 183                 family = AF_INET;
 184                 goto retry;
 185         }
 186
 187         if (rc) {
 188                 CERROR("Can't create socket: %d\n", rc);
 189                 return ERR_PTR(rc);
 190         }
 191
 192         sock->sk->sk_reuseport = 1;
 193
 194         if (interface >= 0 || local_port != 0) {
 195                 struct sockaddr_storage locaddr = {};
 196
 197                 switch (family) {
 198                 case AF_INET: {
 199                         struct sockaddr_in *sin = (void *)&locaddr;
 200
 201                         sin->sin_family = AF_INET;
 202                         sin->sin_addr.s_addr = INADDR_ANY;
 203                         if (interface >= 0 && remaddr) {
 204                                 struct sockaddr_in *rem = (void *)remaddr;
 205                                 __u32 ip;
 206
 207                                 rc = choose_ipv4_src(&ip,
 208                                                      interface,
 209                                                      ntohl(rem->sin_addr.s_addr),
 210                                                      ns);
 211                                 if (rc)
 212                                         goto failed;
 213                                 sin->sin_addr.s_addr = htonl(ip);
 214                         }
 215                         sin->sin_port = htons(local_port);
 216                         break;
 217                 }
 218 #if IS_ENABLED(CONFIG_IPV6)
 219                 case AF_INET6: {
 220                         struct sockaddr_in6 *sin6 = (void *)&locaddr;
 221                         int val = 0;
 222
 223                         sin6->sin6_family = AF_INET6;
 224                         sin6->sin6_addr = in6addr_any;
 225
 226                         /* Make sure we get both IPv4 and IPv6 connections.
 227                          * This is the default, but it can be overridden so we
 228                          * force it back.
 229                          */
 230 #ifdef HAVE_KERNEL_SETSOCKOPT
 231                         kernel_setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
 232                                           (char *) &val, sizeof(val));
 233 #elif defined(_LINUX_SOCKPTR_H)
 234                         /* sockptr_t was introduced around
 235                          * v5.8-rc4-1952-ga7b75c5a8c41 and allows a
 236                          * kernel address to be passed to ->setsockopt
 237                          */
 238                         if (ipv6_only_sock(sock->sk)) {
 239                                 sockptr_t optval = KERNEL_SOCKPTR(&val);
 240
 241                                 sock->ops->setsockopt(sock,
 242                                                       IPPROTO_IPV6, IPV6_V6ONLY,
 243                                                       optval, sizeof(val));
 244                         }
 245 #else
 246                         /* From v5.7-rc6-2614-g5a892ff2facb when
 247                          * kernel_setsockopt() was removed until
 248                          * sockptr_t (above) there is no clean way to
 249                          * pass kernel address to setsockopt.  We could
 250                          * use get_fs()/set_fs(), but in this particular
 251                          * situation there is an easier way.  It depends
 252                          * on the fact that at least for these few
 253                          * kernels a NULL address to ipv6_setsockopt()
 254                          * is treated like the address of a zero.
 255                          */
 256                         if (ipv6_only_sock(sock->sk) && !val) {
 257                                 void *optval = NULL;
 258
 259                                 sock->ops->setsockopt(sock,
 260                                                       IPPROTO_IPV6, IPV6_V6ONLY,
 261                                                       optval, sizeof(val));
 262                         }
 263 #endif /* HAVE_KERNEL_SETSOCKOPT */
 264
 265                         if (interface >= 0 && remaddr) {
 266                                 struct sockaddr_in6 *rem = (void *)remaddr;
 267
 268                                 ipv6_dev_get_saddr(ns,
 269                                                    dev_get_by_index(ns,
 270                                                                     interface),
 271                                                    &rem->sin6_addr, 0,
 272                                                    &sin6->sin6_addr);
 273                         }
 274                         sin6->sin6_port = htons(local_port);
 275                         break;
 276                 }
 277 #endif /* IS_ENABLED(CONFIG_IPV6) */
 278                 }
 279                 rc = kernel_bind(sock, (struct sockaddr *)&locaddr,
 280                                  sizeof(locaddr));
 281                 if (rc == -EADDRINUSE) {
 282                         CDEBUG(D_NET, "Port %d already in use\n", local_port);
 283                         goto failed;
 284                 }
 285                 if (rc != 0) {
 286                         CERROR("Error trying to bind to %pISc/%d: rc = %d\n",
 287                                &locaddr, local_port, rc);
 288                         goto failed;
 289                 }
 290         }
 291         return sock;
 292
 293 failed:
 294         sock_release(sock);
 295         return ERR_PTR(rc);
 296 }
 297
 298 void
 299 lnet_sock_setbuf(struct socket *sock, int txbufsize, int rxbufsize)
 300 {
 301         struct sock *sk = sock->sk;
 302
 303         if (txbufsize != 0) {
 304                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
 305                 sk->sk_sndbuf = txbufsize;
 306                 sk->sk_write_space(sk);
 307         }
 308
 309         if (rxbufsize != 0) {
 310                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
 311                 sk->sk_sndbuf = rxbufsize;
 312         }
 313 }
 314 EXPORT_SYMBOL(lnet_sock_setbuf);
 315
 316 int
 317 lnet_sock_getaddr(struct socket *sock, bool remote,
 318                   struct sockaddr_storage *peer)
 319 {
 320         int rc;
 321 #ifndef HAVE_KERN_SOCK_GETNAME_2ARGS
 322         int len = sizeof(*peer);
 323 #endif
 324
 325         if (remote)
 326                 rc = lnet_kernel_getpeername(sock,
 327                                              (struct sockaddr *)peer, &len);
 328         else
 329                 rc = lnet_kernel_getsockname(sock,
 330                                              (struct sockaddr *)peer, &len);
 331         if (rc < 0) {
 332                 CERROR("Error %d getting sock %s IP/port\n",
 333                         rc, remote ? "peer" : "local");
 334                 return rc;
 335         }
 336         if (peer->ss_family == AF_INET6) {
 337                 struct sockaddr_in6 *in6 = (void *)peer;
 338                 struct sockaddr_in *in = (void *)peer;
 339                 short port = in6->sin6_port;
 340
 341                 if (ipv6_addr_v4mapped(&in6->sin6_addr)) {
 342                         /* Pretend it is a v4 socket */
 343                         memset(in, 0, sizeof(*in));
 344                         in->sin_family = AF_INET;
 345                         in->sin_port = port;
 346                         memcpy(&in->sin_addr, &in6->sin6_addr.s6_addr32[3], 4);
 347                 }
 348         }
 349         return 0;
 350 }
 351 EXPORT_SYMBOL(lnet_sock_getaddr);
 352
 353 void lnet_sock_getbuf(struct socket *sock, int *txbufsize, int *rxbufsize)
 354 {
 355         if (txbufsize != NULL)
 356                 *txbufsize = sock->sk->sk_sndbuf;
 357
 358         if (rxbufsize != NULL)
 359                 *rxbufsize = sock->sk->sk_rcvbuf;
 360 }
 361 EXPORT_SYMBOL(lnet_sock_getbuf);
 362
 363 struct socket *
 364 lnet_sock_listen(int local_port, int backlog, struct net *ns)
 365 {
 366         struct socket *sock;
 367         int rc;
 368
 369         sock = lnet_sock_create(-1, NULL, local_port, ns);
 370         if (IS_ERR(sock)) {
 371                 rc = PTR_ERR(sock);
 372                 if (rc == -EADDRINUSE)
 373                         CERROR("Can't create socket: port %d already in use\n",
 374                                local_port);
 375                 return ERR_PTR(rc);
 376         }
 377
 378         rc = kernel_listen(sock, backlog);
 379         if (rc == 0)
 380                 return sock;
 381
 382         CERROR("Can't set listen backlog %d: %d\n", backlog, rc);
 383         sock_release(sock);
 384         return ERR_PTR(rc);
 385 }
 386
 387 struct socket *
 388 lnet_sock_connect(int interface, int local_port,
 389                   struct sockaddr *peeraddr,
 390                   struct net *ns)
 391 {
 392         struct socket *sock;
 393         int rc;
 394
 395         sock = lnet_sock_create(interface, peeraddr, local_port, ns);
 396         if (IS_ERR(sock))
 397                 return sock;
 398
 399         /* Avoid temporary address, they are bad for long-lived
 400          * connections such as lustre mounts.
 401          * RFC4941, section 3.6 suggests that:
 402          *    Individual applications, which have specific
 403          *    knowledge about the normal duration of connections,
 404          *    MAY override this as appropriate.
 405          */
 406         if (peeraddr->sa_family == PF_INET6)
 407                 ip6_sock_set_addr_preferences(sock->sk,
 408                                               IPV6_PREFER_SRC_PUBLIC);
 409
 410         rc = kernel_connect(sock, peeraddr, sizeof(struct sockaddr_in6), 0);
 411         if (rc == 0)
 412                 return sock;
 413
 414         /* EADDRNOTAVAIL probably means we're already connected to the same
 415          * peer/port on the same local port on a differently typed
 416          * connection.  Let our caller retry with a different local
 417          * port... */
 418
 419         CDEBUG_LIMIT(rc == -EADDRNOTAVAIL ? D_NET : D_NETERROR,
 420                      "Error %d connecting %d -> %pIScp\n", rc,
 421                      local_port, peeraddr);
 422
 423         sock_release(sock);
 424         return ERR_PTR(rc);
 425 }