proto_common.c revision 223143
1210284Sjmallett/*- 2232812Sjmallett * Copyright (c) 2009-2010 The FreeBSD Foundation 3215990Sjmallett * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net> 4210284Sjmallett * All rights reserved. 5210284Sjmallett * 6215990Sjmallett * This software was developed by Pawel Jakub Dawidek under sponsorship from 7215990Sjmallett * the FreeBSD Foundation. 8215990Sjmallett * 9210284Sjmallett * Redistribution and use in source and binary forms, with or without 10215990Sjmallett * modification, are permitted provided that the following conditions 11215990Sjmallett * are met: 12210284Sjmallett * 1. Redistributions of source code must retain the above copyright 13215990Sjmallett * notice, this list of conditions and the following disclaimer. 14215990Sjmallett * 2. Redistributions in binary form must reproduce the above copyright 15215990Sjmallett * notice, this list of conditions and the following disclaimer in the 16215990Sjmallett * documentation and/or other materials provided with the distribution. 17210284Sjmallett * 18232812Sjmallett * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 19215990Sjmallett * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20215990Sjmallett * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21215990Sjmallett * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 22210284Sjmallett * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23215990Sjmallett * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24215990Sjmallett * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25215990Sjmallett * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26215990Sjmallett * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27210284Sjmallett * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28215990Sjmallett * SUCH DAMAGE. 29232812Sjmallett */ 30215990Sjmallett 31215990Sjmallett#include <sys/cdefs.h> 32215990Sjmallett__FBSDID("$FreeBSD: head/sbin/hastd/proto_common.c 223143 2011-06-16 08:31:06Z sobomax $"); 33215990Sjmallett 34215990Sjmallett#include <sys/types.h> 35215990Sjmallett#include <sys/socket.h> 36215990Sjmallett 37215990Sjmallett#include <errno.h> 38215990Sjmallett#include <fcntl.h> 39210284Sjmallett#include <stdbool.h> 40210284Sjmallett#include <stdlib.h> 41210284Sjmallett#include <strings.h> 42210284Sjmallett#include <unistd.h> 43210284Sjmallett 44210284Sjmallett#include "pjdlog.h" 45210284Sjmallett#include "proto_impl.h" 46210284Sjmallett 47210284Sjmallett/* Maximum size of packet we want to use when sending data. */ 48210284Sjmallett#ifndef MAX_SEND_SIZE 49210284Sjmallett#define MAX_SEND_SIZE 32768 50210284Sjmallett#endif 51210284Sjmallett 52210284Sjmallettstatic bool 53210284Sjmallettblocking_socket(int sock) 54210284Sjmallett{ 55210284Sjmallett int flags; 56210284Sjmallett 57210284Sjmallett flags = fcntl(sock, F_GETFL); 58210284Sjmallett PJDLOG_ASSERT(flags >= 0); 59210284Sjmallett return ((flags & O_NONBLOCK) == 0); 60210284Sjmallett} 61210284Sjmallett 62210284Sjmallettstatic int 63210284Sjmallettproto_descriptor_send(int sock, int fd) 64232812Sjmallett{ 65210284Sjmallett unsigned char ctrl[CMSG_SPACE(sizeof(fd))]; 66210284Sjmallett struct msghdr msg; 67210284Sjmallett struct cmsghdr *cmsg; 68210284Sjmallett 69210284Sjmallett PJDLOG_ASSERT(sock >= 0); 70210284Sjmallett PJDLOG_ASSERT(fd >= 0); 71210284Sjmallett 72215990Sjmallett bzero(&msg, sizeof(msg)); 73232812Sjmallett bzero(&ctrl, sizeof(ctrl)); 74232812Sjmallett 75232812Sjmallett msg.msg_iov = NULL; 76210284Sjmallett msg.msg_iovlen = 0; 77215990Sjmallett msg.msg_control = ctrl; 78210284Sjmallett msg.msg_controllen = sizeof(ctrl); 79232812Sjmallett 80210284Sjmallett cmsg = CMSG_FIRSTHDR(&msg); 81210284Sjmallett cmsg->cmsg_level = SOL_SOCKET; 82210284Sjmallett cmsg->cmsg_type = SCM_RIGHTS; 83243473Sjmallett cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 84243473Sjmallett bcopy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 85243473Sjmallett 86243473Sjmallett if (sendmsg(sock, &msg, 0) == -1) 87243473Sjmallett return (errno); 88243473Sjmallett 89243473Sjmallett return (0); 90243473Sjmallett} 91243473Sjmallett 92243473Sjmallettint 93243473Sjmallettproto_common_send(int sock, const unsigned char *data, size_t size, int fd) 94243473Sjmallett{ 95243473Sjmallett ssize_t done; 96243473Sjmallett size_t sendsize; 97243473Sjmallett int errcount = 0; 98243473Sjmallett 99243473Sjmallett PJDLOG_ASSERT(sock >= 0); 100210284Sjmallett 101210284Sjmallett if (data == NULL) { 102210284Sjmallett /* The caller is just trying to decide about direction. */ 103210284Sjmallett 104210284Sjmallett PJDLOG_ASSERT(size == 0); 105210284Sjmallett 106210284Sjmallett if (shutdown(sock, SHUT_RD) == -1) 107210284Sjmallett return (errno); 108210284Sjmallett return (0); 109210284Sjmallett } 110210284Sjmallett 111210284Sjmallett PJDLOG_ASSERT(data != NULL); 112210284Sjmallett PJDLOG_ASSERT(size > 0); 113210284Sjmallett 114210284Sjmallett do { 115210284Sjmallett sendsize = size < MAX_SEND_SIZE ? size : MAX_SEND_SIZE; 116210284Sjmallett done = send(sock, data, sendsize, MSG_NOSIGNAL); 117210284Sjmallett if (done == 0) { 118210284Sjmallett return (ENOTCONN); 119210284Sjmallett } else if (done < 0) { 120210284Sjmallett if (errno == EINTR) 121210284Sjmallett continue; 122210284Sjmallett if (errno == ENOBUFS) { 123210284Sjmallett /* 124210284Sjmallett * If there are no buffers we retry. 125210284Sjmallett * After each try we increase delay before the 126210284Sjmallett * next one and we give up after fifteen times. 127210284Sjmallett * This gives 11s of total wait time. 128210284Sjmallett */ 129210284Sjmallett if (errcount == 15) { 130210284Sjmallett pjdlog_warning("Getting ENOBUFS errors for 11s on send(), giving up."); 131210284Sjmallett } else { 132210284Sjmallett if (errcount == 0) 133210284Sjmallett pjdlog_warning("Got ENOBUFS error on send(), retrying for a bit."); 134210284Sjmallett errcount++; 135210284Sjmallett usleep(100000 * errcount); 136210284Sjmallett continue; 137210284Sjmallett } 138210284Sjmallett } 139210284Sjmallett /* 140210284Sjmallett * If this is blocking socket and we got EAGAIN, this 141210284Sjmallett * means the request timed out. Translate errno to 142210284Sjmallett * ETIMEDOUT, to give administrator a hint to 143210284Sjmallett * eventually increase timeout. 144210284Sjmallett */ 145210284Sjmallett if (errno == EAGAIN && blocking_socket(sock)) 146210284Sjmallett errno = ETIMEDOUT; 147210284Sjmallett return (errno); 148210284Sjmallett } 149210284Sjmallett data += done; 150210284Sjmallett size -= done; 151210284Sjmallett } while (size > 0); 152210284Sjmallett if (errcount > 0) { 153210284Sjmallett pjdlog_info("Data sent successfully after %d ENOBUFS error%s.", 154210284Sjmallett errcount, errcount == 1 ? "" : "s"); 155210284Sjmallett } 156210284Sjmallett 157210284Sjmallett if (fd == -1) 158210284Sjmallett return (0); 159210284Sjmallett return (proto_descriptor_send(sock, fd)); 160210284Sjmallett} 161210284Sjmallett 162210284Sjmallettstatic int 163210284Sjmallettproto_descriptor_recv(int sock, int *fdp) 164232812Sjmallett{ 165210284Sjmallett unsigned char ctrl[CMSG_SPACE(sizeof(*fdp))]; 166210284Sjmallett struct msghdr msg; 167210284Sjmallett struct cmsghdr *cmsg; 168210284Sjmallett 169210284Sjmallett PJDLOG_ASSERT(sock >= 0); 170210284Sjmallett PJDLOG_ASSERT(fdp != NULL); 171210284Sjmallett 172210284Sjmallett bzero(&msg, sizeof(msg)); 173210284Sjmallett bzero(&ctrl, sizeof(ctrl)); 174210284Sjmallett 175210284Sjmallett msg.msg_iov = NULL; 176210284Sjmallett msg.msg_iovlen = 0; 177210284Sjmallett msg.msg_control = ctrl; 178210284Sjmallett msg.msg_controllen = sizeof(ctrl); 179210284Sjmallett 180210284Sjmallett if (recvmsg(sock, &msg, 0) == -1) 181210284Sjmallett return (errno); 182210284Sjmallett 183210284Sjmallett cmsg = CMSG_FIRSTHDR(&msg); 184210284Sjmallett if (cmsg->cmsg_level != SOL_SOCKET || 185232812Sjmallett cmsg->cmsg_type != SCM_RIGHTS) { 186232812Sjmallett return (EINVAL); 187232812Sjmallett } 188232812Sjmallett bcopy(CMSG_DATA(cmsg), fdp, sizeof(*fdp)); 189232812Sjmallett 190232812Sjmallett return (0); 191232812Sjmallett} 192232812Sjmallett 193232812Sjmallettint 194232812Sjmallettproto_common_recv(int sock, unsigned char *data, size_t size, int *fdp) 195232812Sjmallett{ 196232812Sjmallett ssize_t done; 197232812Sjmallett 198232812Sjmallett PJDLOG_ASSERT(sock >= 0); 199232812Sjmallett 200232812Sjmallett if (data == NULL) { 201232812Sjmallett /* The caller is just trying to decide about direction. */ 202232812Sjmallett 203232812Sjmallett PJDLOG_ASSERT(size == 0); 204232812Sjmallett 205232812Sjmallett if (shutdown(sock, SHUT_WR) == -1) 206232812Sjmallett return (errno); 207232812Sjmallett return (0); 208232812Sjmallett } 209232812Sjmallett 210232812Sjmallett PJDLOG_ASSERT(data != NULL); 211232812Sjmallett PJDLOG_ASSERT(size > 0); 212232812Sjmallett 213232812Sjmallett do { 214232812Sjmallett done = recv(sock, data, size, MSG_WAITALL); 215232812Sjmallett } while (done == -1 && errno == EINTR); 216232812Sjmallett if (done == 0) { 217232812Sjmallett return (ENOTCONN); 218232812Sjmallett } else if (done < 0) { 219232812Sjmallett /* 220232812Sjmallett * If this is blocking socket and we got EAGAIN, this 221232812Sjmallett * means the request timed out. Translate errno to 222232812Sjmallett * ETIMEDOUT, to give administrator a hint to 223232812Sjmallett * eventually increase timeout. 224232812Sjmallett */ 225232812Sjmallett if (errno == EAGAIN && blocking_socket(sock)) 226232812Sjmallett errno = ETIMEDOUT; 227232812Sjmallett return (errno); 228232812Sjmallett } 229232812Sjmallett if (fdp == NULL) 230232812Sjmallett return (0); 231232812Sjmallett return (proto_descriptor_recv(sock, fdp)); 232232812Sjmallett} 233232812Sjmallett