| /* |
| * |
| * 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. |
| * |
| */ |
| |
| #include <grpc/support/port_platform.h> |
| #ifdef GPR_POSIX_SOCKET |
| |
| #include "test/core/util/port.h" |
| |
| #include <netinet/in.h> |
| #include <sys/socket.h> |
| #include <stdio.h> |
| #include <errno.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| #include <grpc/support/log.h> |
| |
| #define NUM_RANDOM_PORTS_TO_PICK 100 |
| |
| static int is_port_available(int *port, int is_tcp) { |
| const int proto = is_tcp ? IPPROTO_TCP : 0; |
| const int fd = socket(AF_INET, is_tcp ? SOCK_STREAM : SOCK_DGRAM, proto); |
| int one = 1; |
| struct sockaddr_in addr; |
| socklen_t alen = sizeof(addr); |
| int actual_port; |
| |
| GPR_ASSERT(*port >= 0); |
| GPR_ASSERT(*port <= 65535); |
| if (fd < 0) { |
| gpr_log(GPR_ERROR, "socket() failed: %s", strerror(errno)); |
| return 0; |
| } |
| |
| /* Reuseaddr lets us start up a server immediately after it exits */ |
| if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0) { |
| gpr_log(GPR_ERROR, "setsockopt() failed: %s", strerror(errno)); |
| close(fd); |
| return 0; |
| } |
| |
| /* Try binding to port */ |
| addr.sin_family = AF_INET; |
| addr.sin_addr.s_addr = INADDR_ANY; |
| addr.sin_port = htons(*port); |
| if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) { |
| gpr_log(GPR_DEBUG, "bind(port=%d) failed: %s", *port, strerror(errno)); |
| close(fd); |
| return 0; |
| } |
| |
| /* Get the bound port number */ |
| if (getsockname(fd, (struct sockaddr *)&addr, &alen) < 0) { |
| gpr_log(GPR_ERROR, "getsockname() failed: %s", strerror(errno)); |
| close(fd); |
| return 0; |
| } |
| GPR_ASSERT(alen <= sizeof(addr)); |
| actual_port = ntohs(addr.sin_port); |
| GPR_ASSERT(actual_port > 0); |
| if (*port == 0) { |
| *port = actual_port; |
| } else { |
| GPR_ASSERT(*port == actual_port); |
| } |
| |
| close(fd); |
| return 1; |
| } |
| |
| int grpc_pick_unused_port(void) { |
| /* We repeatedly pick a port and then see whether or not it is |
| available for use both as a TCP socket and a UDP socket. First, we |
| pick a random large port number. For subsequent |
| iterations, we bind to an anonymous port and let the OS pick the |
| port number. The random port picking reduces the probability of |
| races with other processes on kernels that want to reuse the same |
| port numbers over and over. */ |
| |
| /* In alternating iterations we try UDP ports before TCP ports UDP |
| ports -- it could be the case that this machine has been using up |
| UDP ports and they are scarcer. */ |
| |
| /* Type of port to first pick in next iteration */ |
| int is_tcp = 1; |
| int try = 0; |
| |
| for (;;) { |
| int port; |
| if (try == 0) { |
| port = getpid() % (65536 - 30000) + 30000; |
| } else if (try < NUM_RANDOM_PORTS_TO_PICK) { |
| port = rand() % (65536 - 30000) + 30000; |
| } else { |
| port = 0; |
| } |
| |
| if (!is_port_available(&port, is_tcp)) { |
| continue; |
| } |
| |
| GPR_ASSERT(port > 0); |
| /* Check that the port # is free for the other type of socket also */ |
| if (!is_port_available(&port, !is_tcp)) { |
| /* In the next iteration try to bind to the other type first |
| because perhaps it is more rare. */ |
| is_tcp = !is_tcp; |
| continue; |
| } |
| |
| /* TODO(ctiller): consider caching this port in some structure, to avoid |
| handing it out again */ |
| |
| return port; |
| } |
| |
| /* The port iterator reached the end without finding a suitable port. */ |
| return 0; |
| } |
| |
| int grpc_pick_unused_port_or_die(void) { |
| int port = grpc_pick_unused_port(); |
| GPR_ASSERT(port > 0); |
| return port; |
| } |
| |
| #endif /* GPR_POSIX_SOCKET */ |