Added udp_server.{h,cc}.

Makefile

@@ -3283,6 +3283,7 @@ LIBGRPC_SRC = \
     src/core/iomgr/tcp_server_windows.c \
     src/core/iomgr/tcp_windows.c \
     src/core/iomgr/time_averaged_stats.c \
+    src/core/iomgr/udp_server.c \
     src/core/iomgr/wakeup_fd_eventfd.c \
     src/core/iomgr/wakeup_fd_nospecial.c \
     src/core/iomgr/wakeup_fd_pipe.c \
@@ -3543,6 +3544,7 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/iomgr/tcp_server_windows.c \
     src/core/iomgr/tcp_windows.c \
     src/core/iomgr/time_averaged_stats.c \
+    src/core/iomgr/udp_server.c \
     src/core/iomgr/wakeup_fd_eventfd.c \
     src/core/iomgr/wakeup_fd_nospecial.c \
     src/core/iomgr/wakeup_fd_pipe.c \

src/core/iomgr/udp_server.c

@@ -0,0 +1,400 @@
+/* FIXME: "posix" files shouldn't be depending on _GNU_SOURCE */
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_POSIX_SOCKET
+
+#include "src/core/iomgr/udp_server.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include "src/core/iomgr/fd_posix.h"
+#include "src/core/iomgr/pollset_posix.h"
+#include "src/core/iomgr/resolve_address.h"
+#include "src/core/iomgr/sockaddr_utils.h"
+#include "src/core/iomgr/socket_utils_posix.h"
+#include "src/core/support/string.h"
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/time.h>
+
+#define INIT_PORT_CAP 2
+
+/* one listening port */
+typedef struct {
+  int fd;
+  grpc_fd *emfd;
+  grpc_udp_server *server;
+  union {
+    gpr_uint8 untyped[GRPC_MAX_SOCKADDR_SIZE];
+    struct sockaddr sockaddr;
+    struct sockaddr_un un;
+  } addr;
+  int addr_len;
+  grpc_iomgr_closure read_closure;
+  grpc_iomgr_closure destroyed_closure;
+  grpc_udp_server_read_cb read_cb;
+} server_port;
+
+static void unlink_if_unix_domain_socket(const struct sockaddr_un *un) {
+  struct stat st;
+
+  if (stat(un->sun_path, &st) == 0 && (st.st_mode & S_IFMT) == S_IFSOCK) {
+    unlink(un->sun_path);
+  }
+}
+
+/* the overall server */
+struct grpc_udp_server {
+  grpc_udp_server_cb cb;
+  void *cb_arg;
+
+  gpr_mu mu;
+  gpr_cv cv;
+
+  /* active port count: how many ports are actually still listening */
+  size_t active_ports;
+  /* destroyed port count: how many ports are completely destroyed */
+  size_t destroyed_ports;
+
+  /* is this server shutting down? (boolean) */
+  int shutdown;
+
+  /* all listening ports */
+  server_port *ports;
+  size_t nports;
+  size_t port_capacity;
+
+  /* shutdown callback */
+  void (*shutdown_complete)(void *);
+  void *shutdown_complete_arg;
+
+  /* Called when there is data to read from the underlying FD. */
+  grpc_udp_server_read_cb read_cb;
+};
+
+grpc_udp_server *grpc_udp_server_create(void) {
+  grpc_udp_server *s = gpr_malloc(sizeof(grpc_udp_server));
+  gpr_mu_init(&s->mu);
+  gpr_cv_init(&s->cv);
+  s->active_ports = 0;
+  s->destroyed_ports = 0;
+  s->shutdown = 0;
+  s->cb = NULL;
+  s->cb_arg = NULL;
+  s->ports = gpr_malloc(sizeof(server_port) * INIT_PORT_CAP);
+  s->nports = 0;
+  s->port_capacity = INIT_PORT_CAP;
+
+  fprintf(stderr, "grpc_udp_server_create Created UDP server\n");
+  return s;
+}
+
+static void finish_shutdown(grpc_udp_server *s) {
+  s->shutdown_complete(s->shutdown_complete_arg);
+
+  gpr_mu_destroy(&s->mu);
+  gpr_cv_destroy(&s->cv);
+
+  gpr_free(s->ports);
+  gpr_free(s);
+}
+
+static void destroyed_port(void *server, int success) {
+  grpc_udp_server *s = server;
+  gpr_mu_lock(&s->mu);
+  s->destroyed_ports++;
+  if (s->destroyed_ports == s->nports) {
+    gpr_mu_unlock(&s->mu);
+    finish_shutdown(s);
+  } else {
+    gpr_mu_unlock(&s->mu);
+  }
+}
+
+static void dont_care_about_shutdown_completion(void *ignored) {}
+
+/* called when all listening endpoints have been shutdown, so no further
+   events will be received on them - at this point it's safe to destroy
+   things */
+static void deactivated_all_ports(grpc_udp_server *s) {
+  size_t i;
+
+  /* delete ALL the things */
+  gpr_mu_lock(&s->mu);
+
+  if (!s->shutdown) {
+    gpr_mu_unlock(&s->mu);
+    return;
+  }
+
+  if (s->nports) {
+    for (i = 0; i < s->nports; i++) {
+      server_port *sp = &s->ports[i];
+      if (sp->addr.sockaddr.sa_family == AF_UNIX) {
+        unlink_if_unix_domain_socket(&sp->addr.un);
+      }
+      sp->destroyed_closure.cb = destroyed_port;
+      sp->destroyed_closure.cb_arg = s;
+      grpc_fd_orphan(sp->emfd, &sp->destroyed_closure, "udp_listener_shutdown");
+    }
+    gpr_mu_unlock(&s->mu);
+  } else {
+    gpr_mu_unlock(&s->mu);
+    finish_shutdown(s);
+  }
+}
+
+void grpc_udp_server_destroy(
+    grpc_udp_server *s, void (*shutdown_complete)(void *shutdown_complete_arg),
+    void *shutdown_complete_arg) {
+  size_t i;
+  gpr_mu_lock(&s->mu);
+
+  GPR_ASSERT(!s->shutdown);
+  s->shutdown = 1;
+
+  s->shutdown_complete = shutdown_complete
+                             ? shutdown_complete
+                             : dont_care_about_shutdown_completion;
+  s->shutdown_complete_arg = shutdown_complete_arg;
+
+  /* shutdown all fd's */
+  if (s->active_ports) {
+    for (i = 0; i < s->nports; i++) {
+      grpc_fd_shutdown(s->ports[i].emfd);
+    }
+    gpr_mu_unlock(&s->mu);
+  } else {
+    gpr_mu_unlock(&s->mu);
+    deactivated_all_ports(s);
+  }
+}
+
+/* Prepare a recently-created socket for listening. */
+static int prepare_socket(int fd, const struct sockaddr *addr, int addr_len) {
+  struct sockaddr_storage sockname_temp;
+  socklen_t sockname_len;
+  int get_local_ip;
+  int rc;
+
+  if (fd < 0) {
+    goto error;
+  }
+
+  get_local_ip = 1;
+  rc = setsockopt(fd, IPPROTO_IP, IP_PKTINFO,
+                      &get_local_ip, sizeof(get_local_ip));
+  if (rc == 0 && addr->sa_family == AF_INET6) {
+    rc = setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
+                    &get_local_ip, sizeof(get_local_ip));
+  }
+
+  if (bind(fd, addr, addr_len) < 0) {
+    char *addr_str;
+    grpc_sockaddr_to_string(&addr_str, addr, 0);
+    gpr_log(GPR_ERROR, "bind addr=%s: %s", addr_str, strerror(errno));
+    gpr_free(addr_str);
+    goto error;
+  }
+
+  sockname_len = sizeof(sockname_temp);
+  if (getsockname(fd, (struct sockaddr *)&sockname_temp, &sockname_len) < 0) {
+    goto error;
+  }
+
+  return grpc_sockaddr_get_port((struct sockaddr *)&sockname_temp);
+
+error:
+  if (fd >= 0) {
+    close(fd);
+  }
+  return -1;
+}
+
+/* event manager callback when reads are ready */
+static void on_read(void *arg, int success) {
+  server_port *sp = arg;
+
+  /* Tell the registered callback that data is available to read. */
+  sp->server->read_cb(sp->fd, sp->server->cb, sp->server->cb_arg);
+
+  /* Re-arm the notification event so we get another chance to read. */
+  grpc_fd_notify_on_read(sp->emfd, &sp->read_closure);
+}
+
+static int add_socket_to_server(grpc_udp_server *s, int fd,
+                                const struct sockaddr *addr, int addr_len,
+                                grpc_udp_server_read_cb read_cb) {
+  server_port *sp;
+  int port;
+  char *addr_str;
+  char *name;
+
+  port = prepare_socket(fd, addr, addr_len);
+  if (port >= 0) {
+    grpc_sockaddr_to_string(&addr_str, (struct sockaddr *)&addr, 1);
+    gpr_asprintf(&name, "udp-server-listener:%s", addr_str);
+    gpr_mu_lock(&s->mu);
+    GPR_ASSERT(!s->cb && "must add ports before starting server");
+    /* append it to the list under a lock */
+    if (s->nports == s->port_capacity) {
+      s->port_capacity *= 2;
+      s->ports = gpr_realloc(s->ports, sizeof(server_port) * s->port_capacity);
+    }
+    sp = &s->ports[s->nports++];
+    sp->server = s;
+    sp->fd = fd;
+    sp->emfd = grpc_fd_create(fd, name);
+    memcpy(sp->addr.untyped, addr, addr_len);
+    sp->addr_len = addr_len;
+    sp->read_cb = read_cb;
+    GPR_ASSERT(sp->emfd);
+    gpr_mu_unlock(&s->mu);
+  }
+
+  return port;
+}
+
+int grpc_udp_server_add_port(grpc_udp_server *s, const void *addr,
+                             int addr_len, grpc_udp_server_read_cb read_cb) {
+  int allocated_port1 = -1;
+  int allocated_port2 = -1;
+  unsigned i;
+  int fd;
+  grpc_dualstack_mode dsmode;
+  struct sockaddr_in6 addr6_v4mapped;
+  struct sockaddr_in wild4;
+  struct sockaddr_in6 wild6;
+  struct sockaddr_in addr4_copy;
+  struct sockaddr *allocated_addr = NULL;
+  struct sockaddr_storage sockname_temp;
+  socklen_t sockname_len;
+  int port;
+
+  if (((struct sockaddr *)addr)->sa_family == AF_UNIX) {
+    unlink_if_unix_domain_socket(addr);
+  }
+
+  /* Check if this is a wildcard port, and if so, try to keep the port the same
+     as some previously created listener. */
+  if (grpc_sockaddr_get_port(addr) == 0) {
+    for (i = 0; i < s->nports; i++) {
+      sockname_len = sizeof(sockname_temp);
+      if (0 == getsockname(s->ports[i].fd, (struct sockaddr *)&sockname_temp,
+                           &sockname_len)) {
+        port = grpc_sockaddr_get_port((struct sockaddr *)&sockname_temp);
+        if (port > 0) {
+          allocated_addr = malloc(addr_len);
+          memcpy(allocated_addr, addr, addr_len);
+          grpc_sockaddr_set_port(allocated_addr, port);
+          addr = allocated_addr;
+          break;
+        }
+      }
+    }
+  }
+
+  if (grpc_sockaddr_to_v4mapped(addr, &addr6_v4mapped)) {
+    addr = (const struct sockaddr *)&addr6_v4mapped;
+    addr_len = sizeof(addr6_v4mapped);
+  }
+
+  /* Treat :: or 0.0.0.0 as a family-agnostic wildcard. */
+  if (grpc_sockaddr_is_wildcard(addr, &port)) {
+    grpc_sockaddr_make_wildcards(port, &wild4, &wild6);
+
+    /* Try listening on IPv6 first. */
+    addr = (struct sockaddr *)&wild6;
+    addr_len = sizeof(wild6);
+    fd = grpc_create_dualstack_socket(addr, SOCK_DGRAM, IPPROTO_UDP, &dsmode);
+    allocated_port1 = add_socket_to_server(s, fd, addr, addr_len, read_cb);
+    if (fd >= 0 && dsmode == GRPC_DSMODE_DUALSTACK) {
+      goto done;
+    }
+
+    /* If we didn't get a dualstack socket, also listen on 0.0.0.0. */
+    if (port == 0 && allocated_port1 > 0) {
+      grpc_sockaddr_set_port((struct sockaddr *)&wild4, allocated_port1);
+    }
+    addr = (struct sockaddr *)&wild4;
+    addr_len = sizeof(wild4);
+  }
+
+  fd = grpc_create_dualstack_socket(addr, SOCK_DGRAM, IPPROTO_UDP, &dsmode);
+  if (fd < 0) {
+    gpr_log(GPR_ERROR, "Unable to create socket: %s", strerror(errno));
+  }
+  if (dsmode == GRPC_DSMODE_IPV4 &&
+      grpc_sockaddr_is_v4mapped(addr, &addr4_copy)) {
+    addr = (struct sockaddr *)&addr4_copy;
+    addr_len = sizeof(addr4_copy);
+  }
+  allocated_port2 = add_socket_to_server(s, fd, addr, addr_len, read_cb);
+
+done:
+  fprintf(stderr,
+          "grpc_udp_server_add_port created FD: %d, listening port: %d\n", fd,
+          allocated_port1);
+  gpr_free(allocated_addr);
+  return allocated_port1 >= 0 ? allocated_port1 : allocated_port2;
+}
+
+int grpc_udp_server_get_fd(grpc_udp_server *s, unsigned index) {
+  return (index < s->nports) ? s->ports[index].fd : -1;
+}
+
+void grpc_udp_server_start(grpc_udp_server *s, grpc_pollset **pollsets,
+                           size_t pollset_count,
+                           grpc_udp_server_cb new_transport_cb, void *cb_arg) {
+  size_t i, j;
+  GPR_ASSERT(new_transport_cb);
+  gpr_mu_lock(&s->mu);
+  GPR_ASSERT(!s->cb);
+  GPR_ASSERT(s->active_ports == 0);
+  s->cb = new_transport_cb;
+  s->cb_arg = cb_arg;
+  for (i = 0; i < s->nports; i++) {
+    for (j = 0; j < pollset_count; j++) {
+      grpc_pollset_add_fd(pollsets[j], s->ports[i].emfd);
+    }
+    s->ports[i].read_closure.cb = on_read;
+    s->ports[i].read_closure.cb_arg = &s->ports[i];
+    grpc_fd_notify_on_read(s->ports[i].emfd, &s->ports[i].read_closure);
+    s->active_ports++;
+  }
+  gpr_mu_unlock(&s->mu);
+
+  fprintf(stderr, "grpc_udp_server_start Started UDP server\n");
+}
+
+/*
+void grpc_udp_server_write(server_port *sp,
+                           const char *buffer,
+                           size_t buf_len,
+                           const struct sockaddr* peer_address) {
+  int rc;
+  rc = sendto(sp->fd, buffer, buf_len, 0, peer_address, sizeof(peer_address));
+  if (rc < 0) {
+    gpr_log(GPR_ERROR, "Unable to send data: %s", strerror(errno));
+  }
+}
+*/
+
+#endif

src/core/iomgr/udp_server.h

@@ -0,0 +1,83 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_IOMGR_UDP_SERVER_H
+#define GRPC_INTERNAL_CORE_IOMGR_UDP_SERVER_H
+
+#include "src/core/iomgr/endpoint.h"
+
+/* Forward decl of grpc_udp_server */
+typedef struct grpc_udp_server grpc_udp_server;
+
+/* New server callback: ep is the newly connected connection */
+typedef void (*grpc_udp_server_cb)(void *arg, grpc_endpoint *ep);
+
+/* Called when data is available to read from the socket. */
+typedef void (*grpc_udp_server_read_cb)(int fd,
+                                        grpc_udp_server_cb new_transport_cb,
+                                        void *cb_arg);
+
+/* Create a server, initially not bound to any ports */
+grpc_udp_server *grpc_udp_server_create(void);
+
+/* Start listening to bound ports */
+void grpc_udp_server_start(grpc_udp_server *server, grpc_pollset **pollsets,
+                           size_t pollset_count, grpc_udp_server_cb cb,
+                           void *cb_arg);
+
+/* Add a port to the server, returning port number on success, or negative
+   on failure.
+
+   The :: and 0.0.0.0 wildcard addresses are treated identically, accepting
+   both IPv4 and IPv6 connections, but :: is the preferred style.  This usually
+   creates one socket, but possibly two on systems which support IPv6,
+   but not dualstack sockets. */
+
+/* TODO(ctiller): deprecate this, and make grpc_udp_server_add_ports to handle
+                  all of the multiple socket port matching logic in one place */
+int grpc_udp_server_add_port(grpc_udp_server *s, const void *addr, int addr_len,
+                             grpc_udp_server_read_cb read_cb);
+
+void grpc_udp_server_destroy(grpc_udp_server *server,
+                             void (*shutdown_done)(void *shutdown_done_arg),
+                             void *shutdown_done_arg);
+
+/* Write the contents of buffer to the underlying UDP socket. */
+/*
+void grpc_udp_server_write(grpc_udp_server *s,
+                           const char *buffer,
+                           int buf_len,
+                           const struct sockaddr* to);
+                           */
+
+#endif /* GRPC_INTERNAL_CORE_IOMGR_UDP_SERVER_H */