Initial checkin of gRPC to third_party/

third_party/grpc/src/core/iomgr/tcp_server_posix.c

Index: third_party/grpc/src/core/iomgr/tcp_server_posix.c
diff --git a/third_party/grpc/src/core/iomgr/tcp_server_posix.c b/third_party/grpc/src/core/iomgr/tcp_server_posix.c
new file mode 100644
index 0000000000000000000000000000000000000000..5e07f8261c223e4cd410ab2deab9e34cb0d99c2b
--- /dev/null
+++ b/third_party/grpc/src/core/iomgr/tcp_server_posix.c
@@ -0,0 +1,619 @@
+/*
+ *
+ * Copyright 2015-2016, 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.
+ *
+ */
+
+/* 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/tcp_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/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/iomgr/tcp_posix.h"
+#include "src/core/support/string.h"
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/time.h>
+
+#define MIN_SAFE_ACCEPT_QUEUE_SIZE 100
+
+static gpr_once s_init_max_accept_queue_size;
+static int s_max_accept_queue_size;
+
+/* one listening port */
+typedef struct grpc_tcp_listener grpc_tcp_listener;
+struct grpc_tcp_listener {
+  int fd;
+  grpc_fd *emfd;
+  grpc_tcp_server *server;
+  union {
+    uint8_t untyped[GRPC_MAX_SOCKADDR_SIZE];
+    struct sockaddr sockaddr;
+    struct sockaddr_un un;
+  } addr;
+  size_t addr_len;
+  int port;
+  unsigned port_index;
+  unsigned fd_index;
+  grpc_closure read_closure;
+  grpc_closure destroyed_closure;
+  struct grpc_tcp_listener *next;
+  /* When we add a listener, more than one can be created, mainly because of
+     IPv6. A sibling will still be in the normal list, but will be flagged
+     as such. Any action, such as ref or unref, will affect all of the
+     siblings in the list. */
+  struct grpc_tcp_listener *sibling;
+  int is_sibling;
+};
+
+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_tcp_server {
+  gpr_refcount refs;
+  /* Called whenever accept() succeeds on a server port. */
+  grpc_tcp_server_cb on_accept_cb;
+  void *on_accept_cb_arg;
+
+  gpr_mu mu;
+
+  /* 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;
+
+  /* linked list of server ports */
+  grpc_tcp_listener *head;
+  grpc_tcp_listener *tail;
+  unsigned nports;
+
+  /* List of closures passed to shutdown_starting_add(). */
+  grpc_closure_list shutdown_starting;
+
+  /* shutdown callback */
+  grpc_closure *shutdown_complete;
+
+  /* all pollsets interested in new connections */
+  grpc_pollset **pollsets;
+  /* number of pollsets in the pollsets array */
+  size_t pollset_count;
+};
+
+grpc_tcp_server *grpc_tcp_server_create(grpc_closure *shutdown_complete) {
+  grpc_tcp_server *s = gpr_malloc(sizeof(grpc_tcp_server));
+  gpr_ref_init(&s->refs, 1);
+  gpr_mu_init(&s->mu);
+  s->active_ports = 0;
+  s->destroyed_ports = 0;
+  s->shutdown = 0;
+  s->shutdown_starting.head = NULL;
+  s->shutdown_starting.tail = NULL;
+  s->shutdown_complete = shutdown_complete;
+  s->on_accept_cb = NULL;
+  s->on_accept_cb_arg = NULL;
+  s->head = NULL;
+  s->tail = NULL;
+  s->nports = 0;
+  return s;
+}
+
+static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
+  if (s->shutdown_complete != NULL) {
+    grpc_exec_ctx_enqueue(exec_ctx, s->shutdown_complete, true, NULL);
+  }
+
+  gpr_mu_destroy(&s->mu);
+
+  while (s->head) {
+    grpc_tcp_listener *sp = s->head;
+    s->head = sp->next;
+    gpr_free(sp);
+  }
+
+  gpr_free(s);
+}
+
+static void destroyed_port(grpc_exec_ctx *exec_ctx, void *server,
+                           bool success) {
+  grpc_tcp_server *s = server;
+  gpr_mu_lock(&s->mu);
+  s->destroyed_ports++;
+  if (s->destroyed_ports == s->nports) {
+    gpr_mu_unlock(&s->mu);
+    finish_shutdown(exec_ctx, s);
+  } else {
+    GPR_ASSERT(s->destroyed_ports < s->nports);
+    gpr_mu_unlock(&s->mu);
+  }
+}
+
+/* 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_exec_ctx *exec_ctx, grpc_tcp_server *s) {
+  /* delete ALL the things */
+  gpr_mu_lock(&s->mu);
+
+  if (!s->shutdown) {
+    gpr_mu_unlock(&s->mu);
+    return;
+  }
+
+  if (s->head) {
+    grpc_tcp_listener *sp;
+    for (sp = s->head; sp; sp = sp->next) {
+      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(exec_ctx, sp->emfd, &sp->destroyed_closure, NULL,
+                     "tcp_listener_shutdown");
+    }
+    gpr_mu_unlock(&s->mu);
+  } else {
+    gpr_mu_unlock(&s->mu);
+    finish_shutdown(exec_ctx, s);
+  }
+}
+
+static void tcp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
+  gpr_mu_lock(&s->mu);
+
+  GPR_ASSERT(!s->shutdown);
+  s->shutdown = 1;
+
+  /* shutdown all fd's */
+  if (s->active_ports) {
+    grpc_tcp_listener *sp;
+    for (sp = s->head; sp; sp = sp->next) {
+      grpc_fd_shutdown(exec_ctx, sp->emfd);
+    }
+    gpr_mu_unlock(&s->mu);
+  } else {
+    gpr_mu_unlock(&s->mu);
+    deactivated_all_ports(exec_ctx, s);
+  }
+}
+
+/* get max listen queue size on linux */
+static void init_max_accept_queue_size(void) {
+  int n = SOMAXCONN;
+  char buf[64];
+  FILE *fp = fopen("/proc/sys/net/core/somaxconn", "r");
+  if (fp == NULL) {
+    /* 2.4 kernel. */
+    s_max_accept_queue_size = SOMAXCONN;
+    return;
+  }
+  if (fgets(buf, sizeof buf, fp)) {
+    char *end;
+    long i = strtol(buf, &end, 10);
+    if (i > 0 && i <= INT_MAX && end && *end == 0) {
+      n = (int)i;
+    }
+  }
+  fclose(fp);
+  s_max_accept_queue_size = n;
+
+  if (s_max_accept_queue_size < MIN_SAFE_ACCEPT_QUEUE_SIZE) {
+    gpr_log(GPR_INFO,
+            "Suspiciously small accept queue (%d) will probably lead to "
+            "connection drops",
+            s_max_accept_queue_size);
+  }
+}
+
+static int get_max_accept_queue_size(void) {
+  gpr_once_init(&s_init_max_accept_queue_size, init_max_accept_queue_size);
+  return s_max_accept_queue_size;
+}
+
+/* Prepare a recently-created socket for listening. */
+static int prepare_socket(int fd, const struct sockaddr *addr,
+                          size_t addr_len) {
+  struct sockaddr_storage sockname_temp;
+  socklen_t sockname_len;
+
+  if (fd < 0) {
+    goto error;
+  }
+
+  if (!grpc_set_socket_nonblocking(fd, 1) || !grpc_set_socket_cloexec(fd, 1) ||
+      (addr->sa_family != AF_UNIX && (!grpc_set_socket_low_latency(fd, 1) ||
+                                      !grpc_set_socket_reuse_addr(fd, 1))) ||
+      !grpc_set_socket_no_sigpipe_if_possible(fd)) {
+    gpr_log(GPR_ERROR, "Unable to configure socket %d: %s", fd,
+            strerror(errno));
+    goto error;
+  }
+
+  GPR_ASSERT(addr_len < ~(socklen_t)0);
+  if (bind(fd, addr, (socklen_t)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;
+  }
+
+  if (listen(fd, get_max_accept_queue_size()) < 0) {
+    gpr_log(GPR_ERROR, "listen: %s", strerror(errno));
+    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(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
+  grpc_tcp_listener *sp = arg;
+  grpc_tcp_server_acceptor acceptor = {sp->server, sp->port_index,
+                                       sp->fd_index};
+  grpc_fd *fdobj;
+  size_t i;
+
+  if (!success) {
+    goto error;
+  }
+
+  /* loop until accept4 returns EAGAIN, and then re-arm notification */
+  for (;;) {
+    struct sockaddr_storage addr;
+    socklen_t addrlen = sizeof(addr);
+    char *addr_str;
+    char *name;
+    /* Note: If we ever decide to return this address to the user, remember to
+       strip off the ::ffff:0.0.0.0/96 prefix first. */
+    int fd = grpc_accept4(sp->fd, (struct sockaddr *)&addr, &addrlen, 1, 1);
+    if (fd < 0) {
+      switch (errno) {
+        case EINTR:
+          continue;
+        case EAGAIN:
+          grpc_fd_notify_on_read(exec_ctx, sp->emfd, &sp->read_closure);
+          return;
+        default:
+          gpr_log(GPR_ERROR, "Failed accept4: %s", strerror(errno));
+          goto error;
+      }
+    }
+
+    grpc_set_socket_no_sigpipe_if_possible(fd);
+
+    addr_str = grpc_sockaddr_to_uri((struct sockaddr *)&addr);
+    gpr_asprintf(&name, "tcp-server-connection:%s", addr_str);
+
+    if (grpc_tcp_trace) {
+      gpr_log(GPR_DEBUG, "SERVER_CONNECT: incoming connection: %s", addr_str);
+    }
+
+    fdobj = grpc_fd_create(fd, name);
+    /* TODO(ctiller): revise this when we have server-side sharding
+       of channels -- we certainly should not be automatically adding every
+       incoming channel to every pollset owned by the server */
+    for (i = 0; i < sp->server->pollset_count; i++) {
+      grpc_pollset_add_fd(exec_ctx, sp->server->pollsets[i], fdobj);
+    }
+    sp->server->on_accept_cb(
+        exec_ctx, sp->server->on_accept_cb_arg,
+        grpc_tcp_create(fdobj, GRPC_TCP_DEFAULT_READ_SLICE_SIZE, addr_str),
+        &acceptor);
+
+    gpr_free(name);
+    gpr_free(addr_str);
+  }
+
+  GPR_UNREACHABLE_CODE(return );
+
+error:
+  gpr_mu_lock(&sp->server->mu);
+  if (0 == --sp->server->active_ports) {
+    gpr_mu_unlock(&sp->server->mu);
+    deactivated_all_ports(exec_ctx, sp->server);
+  } else {
+    gpr_mu_unlock(&sp->server->mu);
+  }
+}
+
+static grpc_tcp_listener *add_socket_to_server(grpc_tcp_server *s, int fd,
+                                               const struct sockaddr *addr,
+                                               size_t addr_len,
+                                               unsigned port_index,
+                                               unsigned fd_index) {
+  grpc_tcp_listener *sp = NULL;
+  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, "tcp-server-listener:%s", addr_str);
+    gpr_mu_lock(&s->mu);
+    s->nports++;
+    GPR_ASSERT(!s->on_accept_cb && "must add ports before starting server");
+    sp = gpr_malloc(sizeof(grpc_tcp_listener));
+    sp->next = NULL;
+    if (s->head == NULL) {
+      s->head = sp;
+    } else {
+      s->tail->next = sp;
+    }
+    s->tail = sp;
+    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->port = port;
+    sp->port_index = port_index;
+    sp->fd_index = fd_index;
+    sp->is_sibling = 0;
+    sp->sibling = NULL;
+    GPR_ASSERT(sp->emfd);
+    gpr_mu_unlock(&s->mu);
+    gpr_free(addr_str);
+    gpr_free(name);
+  }
+
+  return sp;
+}
+
+int grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
+                             size_t addr_len) {
+  grpc_tcp_listener *sp;
+  grpc_tcp_listener *sp2 = NULL;
+  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;
+  unsigned port_index = 0;
+  unsigned fd_index = 0;
+  if (s->tail != NULL) {
+    port_index = s->tail->port_index + 1;
+  }
+  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 (sp = s->head; sp; sp = sp->next) {
+      sockname_len = sizeof(sockname_temp);
+      if (0 == getsockname(sp->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;
+        }
+      }
+    }
+  }
+
+  sp = NULL;
+
+  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_STREAM, 0, &dsmode);
+    sp = add_socket_to_server(s, fd, addr, addr_len, port_index, fd_index);
+    if (fd >= 0 && dsmode == GRPC_DSMODE_DUALSTACK) {
+      goto done;
+    }
+    if (sp != NULL) {
+      ++fd_index;
+    }
+    /* If we didn't get a dualstack socket, also listen on 0.0.0.0. */
+    if (port == 0 && sp != NULL) {
+      grpc_sockaddr_set_port((struct sockaddr *)&wild4, sp->port);
+      sp2 = sp;
+    }
+    addr = (struct sockaddr *)&wild4;
+    addr_len = sizeof(wild4);
+  }
+
+  fd = grpc_create_dualstack_socket(addr, SOCK_STREAM, 0, &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);
+  }
+  sp = add_socket_to_server(s, fd, addr, addr_len, port_index, fd_index);
+  if (sp2 != NULL && sp != NULL) {
+    sp2->sibling = sp;
+    sp->is_sibling = 1;
+  }
+
+done:
+  gpr_free(allocated_addr);
+  if (sp != NULL) {
+    return sp->port;
+  } else {
+    return -1;
+  }
+}
+
+unsigned grpc_tcp_server_port_fd_count(grpc_tcp_server *s,
+                                       unsigned port_index) {
+  unsigned num_fds = 0;
+  grpc_tcp_listener *sp;
+  for (sp = s->head; sp && port_index != 0; sp = sp->next) {
+    if (!sp->is_sibling) {
+      --port_index;
+    }
+  }
+  for (; sp; sp = sp->sibling, ++num_fds)
+    ;
+  return num_fds;
+}
+
+int grpc_tcp_server_port_fd(grpc_tcp_server *s, unsigned port_index,
+                            unsigned fd_index) {
+  grpc_tcp_listener *sp;
+  for (sp = s->head; sp && port_index != 0; sp = sp->next) {
+    if (!sp->is_sibling) {
+      --port_index;
+    }
+  }
+  for (; sp && fd_index != 0; sp = sp->sibling, --fd_index)
+    ;
+  if (sp) {
+    return sp->fd;
+  } else {
+    return -1;
+  }
+}
+
+void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
+                           grpc_pollset **pollsets, size_t pollset_count,
+                           grpc_tcp_server_cb on_accept_cb,
+                           void *on_accept_cb_arg) {
+  size_t i;
+  grpc_tcp_listener *sp;
+  GPR_ASSERT(on_accept_cb);
+  gpr_mu_lock(&s->mu);
+  GPR_ASSERT(!s->on_accept_cb);
+  GPR_ASSERT(s->active_ports == 0);
+  s->on_accept_cb = on_accept_cb;
+  s->on_accept_cb_arg = on_accept_cb_arg;
+  s->pollsets = pollsets;
+  s->pollset_count = pollset_count;
+  for (sp = s->head; sp; sp = sp->next) {
+    for (i = 0; i < pollset_count; i++) {
+      grpc_pollset_add_fd(exec_ctx, pollsets[i], sp->emfd);
+    }
+    sp->read_closure.cb = on_read;
+    sp->read_closure.cb_arg = sp;
+    grpc_fd_notify_on_read(exec_ctx, sp->emfd, &sp->read_closure);
+    s->active_ports++;
+  }
+  gpr_mu_unlock(&s->mu);
+}
+
+grpc_tcp_server *grpc_tcp_server_ref(grpc_tcp_server *s) {
+  gpr_ref(&s->refs);
+  return s;
+}
+
+void grpc_tcp_server_shutdown_starting_add(grpc_tcp_server *s,
+                                           grpc_closure *shutdown_starting) {
+  gpr_mu_lock(&s->mu);
+  grpc_closure_list_add(&s->shutdown_starting, shutdown_starting, 1);
+  gpr_mu_unlock(&s->mu);
+}
+
+void grpc_tcp_server_unref(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
+  if (gpr_unref(&s->refs)) {
+    /* Complete shutdown_starting work before destroying. */
+    grpc_exec_ctx local_exec_ctx = GRPC_EXEC_CTX_INIT;
+    gpr_mu_lock(&s->mu);
+    grpc_exec_ctx_enqueue_list(&local_exec_ctx, &s->shutdown_starting, NULL);
+    gpr_mu_unlock(&s->mu);
+    if (exec_ctx == NULL) {
+      grpc_exec_ctx_flush(&local_exec_ctx);
+      tcp_server_destroy(&local_exec_ctx, s);
+      grpc_exec_ctx_finish(&local_exec_ctx);
+    } else {
+      grpc_exec_ctx_finish(&local_exec_ctx);
+      tcp_server_destroy(exec_ctx, s);
+    }
+  }
+}
+
+#endif