anet.c

   1 /* anet.c -- Basic TCP socket stuff made a bit less boring
   2  *
   3  * Copyright (c) 2006-2010, Salvatore Sanfilippo <antirez at gmail dot com>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *
   9  *   * Redistributions of source code must retain the above copyright notice,
  10  *     this list of conditions and the following disclaimer.
  11  *   * Redistributions in binary form must reproduce the above copyright
  12  *     notice, this list of conditions and the following disclaimer in the
  13  *     documentation and/or other materials provided with the distribution.
  14  *   * Neither the name of Redis nor the names of its contributors may be used
  15  *     to endorse or promote products derived from this software without
  16  *     specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  28  * POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include "fmacros.h"
  32
  33 #include <sys/types.h>
  34 #include <sys/socket.h>
  35 #include <netinet/in.h>
  36 #include <netinet/tcp.h>
  37 #include <arpa/inet.h>
  38 #include <unistd.h>
  39 #include <fcntl.h>
  40 #include <string.h>
  41 #include <netdb.h>
  42 #include <errno.h>
  43 #include <stdarg.h>
  44 #include <stdio.h>
  45
  46 #include "anet.h"
  47
  48 static void anetSetError(char *err, const char *fmt, ...)
  49 {
  50     va_list ap;
  51
  52     if (!err) return;
  53     va_start(ap, fmt);
  54     vsnprintf(err, ANET_ERR_LEN, fmt, ap);
  55     va_end(ap);
  56 }
  57
  58 int anetNonBlock(char *err, int fd)
  59 {
  60     int flags;
  61
  62     /* Set the socket nonblocking.
  63      * Note that fcntl(2) for F_GETFL and F_SETFL can't be
  64      * interrupted by a signal. */
  65     if ((flags = fcntl(fd, F_GETFL)) == -1) {
  66         anetSetError(err, "fcntl(F_GETFL): %s\n", strerror(errno));
  67         return ANET_ERR;
  68     }
  69     if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) {
  70         anetSetError(err, "fcntl(F_SETFL,O_NONBLOCK): %s\n", strerror(errno));
  71         return ANET_ERR;
  72     }
  73     return ANET_OK;
  74 }
  75
  76 int anetTcpNoDelay(char *err, int fd)
  77 {
  78     int yes = 1;
  79     if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &yes, sizeof(yes)) == -1)
  80     {
  81         anetSetError(err, "setsockopt TCP_NODELAY: %s\n", strerror(errno));
  82         return ANET_ERR;
  83     }
  84     return ANET_OK;
  85 }
  86
  87 int anetSetSendBuffer(char *err, int fd, int buffsize)
  88 {
  89     if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &buffsize, sizeof(buffsize)) == -1)
  90     {
  91         anetSetError(err, "setsockopt SO_SNDBUF: %s\n", strerror(errno));
  92         return ANET_ERR;
  93     }
  94     return ANET_OK;
  95 }
  96
  97 int anetTcpKeepAlive(char *err, int fd)
  98 {
  99     int yes = 1;
 100     if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &yes, sizeof(yes)) == -1) {
 101         anetSetError(err, "setsockopt SO_KEEPALIVE: %s\n", strerror(errno));
 102         return ANET_ERR;
 103     }
 104     return ANET_OK;
 105 }
 106
 107 int anetResolve(char *err, char *host, char *ipbuf)
 108 {
 109     struct sockaddr_in sa;
 110
 111     sa.sin_family = AF_INET;
 112     if (inet_aton(host, &sa.sin_addr) == 0) {
 113         struct hostent *he;
 114
 115         he = gethostbyname(host);
 116         if (he == NULL) {
 117             anetSetError(err, "can't resolve: %s\n", host);
 118             return ANET_ERR;
 119         }
 120         memcpy(&sa.sin_addr, he->h_addr, sizeof(struct in_addr));
 121     }
 122     strcpy(ipbuf,inet_ntoa(sa.sin_addr));
 123     return ANET_OK;
 124 }
 125
 126 #define ANET_CONNECT_NONE 0
 127 #define ANET_CONNECT_NONBLOCK 1
 128 static int anetTcpGenericConnect(char *err, char *addr, int port, int flags)
 129 {
 130     int s, on = 1;
 131     struct sockaddr_in sa;
 132
 133     if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
 134         anetSetError(err, "creating socket: %s\n", strerror(errno));
 135         return ANET_ERR;
 136     }
 137     /* Make sure connection-intensive things like the redis benckmark
 138      * will be able to close/open sockets a zillion of times */
 139     setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
 140
 141     sa.sin_family = AF_INET;
 142     sa.sin_port = htons(port);
 143     if (inet_aton(addr, &sa.sin_addr) == 0) {
 144         struct hostent *he;
 145
 146         he = gethostbyname(addr);
 147         if (he == NULL) {
 148             anetSetError(err, "can't resolve: %s\n", addr);
 149             close(s);
 150             return ANET_ERR;
 151         }
 152         memcpy(&sa.sin_addr, he->h_addr, sizeof(struct in_addr));
 153     }
 154     if (flags & ANET_CONNECT_NONBLOCK) {
 155         if (anetNonBlock(err,s) != ANET_OK)
 156             return ANET_ERR;
 157     }
 158     if (connect(s, (struct sockaddr*)&sa, sizeof(sa)) == -1) {
 159         if (errno == EINPROGRESS &&
 160             flags & ANET_CONNECT_NONBLOCK)
 161             return s;
 162
 163         anetSetError(err, "connect: %s\n", strerror(errno));
 164         close(s);
 165         return ANET_ERR;
 166     }
 167     return s;
 168 }
 169
 170 int anetTcpConnect(char *err, char *addr, int port)
 171 {
 172     return anetTcpGenericConnect(err,addr,port,ANET_CONNECT_NONE);
 173 }
 174
 175 int anetTcpNonBlockConnect(char *err, char *addr, int port)
 176 {
 177     return anetTcpGenericConnect(err,addr,port,ANET_CONNECT_NONBLOCK);
 178 }
 179
 180 /* Like read(2) but make sure 'count' is read before to return
 181  * (unless error or EOF condition is encountered) */
 182 int anetRead(int fd, char *buf, int count)
 183 {
 184     int nread, totlen = 0;
 185     while(totlen != count) {
 186         nread = read(fd,buf,count-totlen);
 187         if (nread == 0) return totlen;
 188         if (nread == -1) return -1;
 189         totlen += nread;
 190         buf += nread;
 191     }
 192     return totlen;
 193 }
 194
 195 /* Like write(2) but make sure 'count' is read before to return
 196  * (unless error is encountered) */
 197 int anetWrite(int fd, char *buf, int count)
 198 {
 199     int nwritten, totlen = 0;
 200     while(totlen != count) {
 201         nwritten = write(fd,buf,count-totlen);
 202         if (nwritten == 0) return totlen;
 203         if (nwritten == -1) return -1;
 204         totlen += nwritten;
 205         buf += nwritten;
 206     }
 207     return totlen;
 208 }
 209
 210 int anetTcpServer(char *err, int port, char *bindaddr)
 211 {
 212     int s, on = 1;
 213     struct sockaddr_in sa;
 214
 215     if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
 216         anetSetError(err, "socket: %s\n", strerror(errno));
 217         return ANET_ERR;
 218     }
 219     if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) {
 220         anetSetError(err, "setsockopt SO_REUSEADDR: %s\n", strerror(errno));
 221         close(s);
 222         return ANET_ERR;
 223     }
 224     memset(&sa,0,sizeof(sa));
 225     sa.sin_family = AF_INET;
 226     sa.sin_port = htons(port);
 227     sa.sin_addr.s_addr = htonl(INADDR_ANY);
 228     if (bindaddr) {
 229         if (inet_aton(bindaddr, &sa.sin_addr) == 0) {
 230             anetSetError(err, "Invalid bind address\n");
 231             close(s);
 232             return ANET_ERR;
 233         }
 234     }
 235     if (bind(s, (struct sockaddr*)&sa, sizeof(sa)) == -1) {
 236         anetSetError(err, "bind: %s\n", strerror(errno));
 237         close(s);
 238         return ANET_ERR;
 239     }
 240     if (listen(s, 511) == -1) { /* the magic 511 constant is from nginx */
 241         anetSetError(err, "listen: %s\n", strerror(errno));
 242         close(s);
 243         return ANET_ERR;
 244     }
 245     return s;
 246 }
 247
 248 int anetAccept(char *err, int serversock, char *ip, int *port)
 249 {
 250     int fd;
 251     struct sockaddr_in sa;
 252     unsigned int saLen;
 253
 254     while(1) {
 255         saLen = sizeof(sa);
 256         fd = accept(serversock, (struct sockaddr*)&sa, &saLen);
 257         if (fd == -1) {
 258             if (errno == EINTR)
 259                 continue;
 260             else {
 261                 anetSetError(err, "accept: %s\n", strerror(errno));
 262                 return ANET_ERR;
 263             }
 264         }
 265         break;
 266     }
 267     if (ip) strcpy(ip,inet_ntoa(sa.sin_addr));
 268     if (port) *port = ntohs(sa.sin_port);
 269     return fd;
 270 }