src/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 <sys/un.h>
  36 #include <netinet/in.h>
  37 #include <netinet/tcp.h>
  38 #include <arpa/inet.h>
  39 #include <unistd.h>
  40 #include <fcntl.h>
  41 #include <string.h>
  42 #include <netdb.h>
  43 #include <errno.h>
  44 #include <stdarg.h>
  45 #include <stdio.h>
  46
  47 #include "anet.h"
  48
  49 static void anetSetError(char *err, const char *fmt, ...)
  50 {
  51     va_list ap;
  52
  53     if (!err) return;
  54     va_start(ap, fmt);
  55     vsnprintf(err, ANET_ERR_LEN, fmt, ap);
  56     va_end(ap);
  57 }
  58
  59 int anetNonBlock(char *err, int fd)
  60 {
  61     int flags;
  62
  63     /* Set the socket nonblocking.
  64      * Note that fcntl(2) for F_GETFL and F_SETFL can't be
  65      * interrupted by a signal. */
  66     if ((flags = fcntl(fd, F_GETFL)) == -1) {
  67         anetSetError(err, "fcntl(F_GETFL): %s", strerror(errno));
  68         return ANET_ERR;
  69     }
  70     if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) {
  71         anetSetError(err, "fcntl(F_SETFL,O_NONBLOCK): %s", strerror(errno));
  72         return ANET_ERR;
  73     }
  74     return ANET_OK;
  75 }
  76
  77 int anetTcpNoDelay(char *err, int fd)
  78 {
  79     int yes = 1;
  80     if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &yes, sizeof(yes)) == -1)
  81     {
  82         anetSetError(err, "setsockopt TCP_NODELAY: %s", strerror(errno));
  83         return ANET_ERR;
  84     }
  85     return ANET_OK;
  86 }
  87
  88 int anetSetSendBuffer(char *err, int fd, int buffsize)
  89 {
  90     if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &buffsize, sizeof(buffsize)) == -1)
  91     {
  92         anetSetError(err, "setsockopt SO_SNDBUF: %s", strerror(errno));
  93         return ANET_ERR;
  94     }
  95     return ANET_OK;
  96 }
  97
  98 int anetTcpKeepAlive(char *err, int fd)
  99 {
 100     int yes = 1;
 101     if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &yes, sizeof(yes)) == -1) {
 102         anetSetError(err, "setsockopt SO_KEEPALIVE: %s", strerror(errno));
 103         return ANET_ERR;
 104     }
 105     return ANET_OK;
 106 }
 107
 108 int anetResolve(char *err, char *host, char *ipbuf)
 109 {
 110     struct sockaddr_in sa;
 111
 112     sa.sin_family = AF_INET;
 113     if (inet_aton(host, &sa.sin_addr) == 0) {
 114         struct hostent *he;
 115
 116         he = gethostbyname(host);
 117         if (he == NULL) {
 118             anetSetError(err, "can't resolve: %s", host);
 119             return ANET_ERR;
 120         }
 121         memcpy(&sa.sin_addr, he->h_addr, sizeof(struct in_addr));
 122     }
 123     strcpy(ipbuf,inet_ntoa(sa.sin_addr));
 124     return ANET_OK;
 125 }
 126
 127 static int anetCreateSocket(char *err, int domain) {
 128     int s, on = 1;
 129     if ((s = socket(domain, SOCK_STREAM, 0)) == -1) {
 130         anetSetError(err, "creating socket: %s", strerror(errno));
 131         return ANET_ERR;
 132     }
 133
 134     /* Make sure connection-intensive things like the redis benckmark
 135      * will be able to close/open sockets a zillion of times */
 136     if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) {
 137         anetSetError(err, "setsockopt SO_REUSEADDR: %s", strerror(errno));
 138         return ANET_ERR;
 139     }
 140     return s;
 141 }
 142
 143 #define ANET_CONNECT_NONE 0
 144 #define ANET_CONNECT_NONBLOCK 1
 145 static int anetTcpGenericConnect(char *err, char *addr, int port, int flags)
 146 {
 147     int s;
 148     struct sockaddr_in sa;
 149
 150     if ((s = anetCreateSocket(err,AF_INET)) == ANET_ERR)
 151         return ANET_ERR;
 152
 153     sa.sin_family = AF_INET;
 154     sa.sin_port = htons(port);
 155     if (inet_aton(addr, &sa.sin_addr) == 0) {
 156         struct hostent *he;
 157
 158         he = gethostbyname(addr);
 159         if (he == NULL) {
 160             anetSetError(err, "can't resolve: %s", addr);
 161             close(s);
 162             return ANET_ERR;
 163         }
 164         memcpy(&sa.sin_addr, he->h_addr, sizeof(struct in_addr));
 165     }
 166     if (flags & ANET_CONNECT_NONBLOCK) {
 167         if (anetNonBlock(err,s) != ANET_OK)
 168             return ANET_ERR;
 169     }
 170     if (connect(s, (struct sockaddr*)&sa, sizeof(sa)) == -1) {
 171         if (errno == EINPROGRESS &&
 172             flags & ANET_CONNECT_NONBLOCK)
 173             return s;
 174
 175         anetSetError(err, "connect: %s", strerror(errno));
 176         close(s);
 177         return ANET_ERR;
 178     }
 179     return s;
 180 }
 181
 182 int anetTcpConnect(char *err, char *addr, int port)
 183 {
 184     return anetTcpGenericConnect(err,addr,port,ANET_CONNECT_NONE);
 185 }
 186
 187 int anetTcpNonBlockConnect(char *err, char *addr, int port)
 188 {
 189     return anetTcpGenericConnect(err,addr,port,ANET_CONNECT_NONBLOCK);
 190 }
 191
 192 int anetUnixGenericConnect(char *err, char *path, int flags)
 193 {
 194     int s;
 195     struct sockaddr_un sa;
 196
 197     if ((s = anetCreateSocket(err,AF_LOCAL)) == ANET_ERR)
 198         return ANET_ERR;
 199
 200     sa.sun_family = AF_LOCAL;
 201     strncpy(sa.sun_path,path,sizeof(sa.sun_path)-1);
 202     if (flags & ANET_CONNECT_NONBLOCK) {
 203         if (anetNonBlock(err,s) != ANET_OK)
 204             return ANET_ERR;
 205     }
 206     if (connect(s,(struct sockaddr*)&sa,sizeof(sa)) == -1) {
 207         if (errno == EINPROGRESS &&
 208             flags & ANET_CONNECT_NONBLOCK)
 209             return s;
 210
 211         anetSetError(err, "connect: %s", strerror(errno));
 212         close(s);
 213         return ANET_ERR;
 214     }
 215     return s;
 216 }
 217
 218 int anetUnixConnect(char *err, char *path)
 219 {
 220     return anetUnixGenericConnect(err,path,ANET_CONNECT_NONE);
 221 }
 222
 223 int anetUnixNonBlockConnect(char *err, char *path)
 224 {
 225     return anetUnixGenericConnect(err,path,ANET_CONNECT_NONBLOCK);
 226 }
 227
 228 /* Like read(2) but make sure 'count' is read before to return
 229  * (unless error or EOF condition is encountered) */
 230 int anetRead(int fd, char *buf, int count)
 231 {
 232     int nread, totlen = 0;
 233     while(totlen != count) {
 234         nread = read(fd,buf,count-totlen);
 235         if (nread == 0) return totlen;
 236         if (nread == -1) return -1;
 237         totlen += nread;
 238         buf += nread;
 239     }
 240     return totlen;
 241 }
 242
 243 /* Like write(2) but make sure 'count' is read before to return
 244  * (unless error is encountered) */
 245 int anetWrite(int fd, char *buf, int count)
 246 {
 247     int nwritten, totlen = 0;
 248     while(totlen != count) {
 249         nwritten = write(fd,buf,count-totlen);
 250         if (nwritten == 0) return totlen;
 251         if (nwritten == -1) return -1;
 252         totlen += nwritten;
 253         buf += nwritten;
 254     }
 255     return totlen;
 256 }
 257
 258 static int anetListen(char *err, int s, struct sockaddr *sa, socklen_t len) {
 259     if (bind(s,sa,len) == -1) {
 260         anetSetError(err, "bind: %s", strerror(errno));
 261         close(s);
 262         return ANET_ERR;
 263     }
 264     if (listen(s, 511) == -1) { /* the magic 511 constant is from nginx */
 265         anetSetError(err, "listen: %s", strerror(errno));
 266         close(s);
 267         return ANET_ERR;
 268     }
 269     return ANET_OK;
 270 }
 271
 272 int anetTcpServer(char *err, int port, char *bindaddr)
 273 {
 274     int s;
 275     struct sockaddr_in sa;
 276
 277     if ((s = anetCreateSocket(err,AF_INET)) == ANET_ERR)
 278         return ANET_ERR;
 279
 280     memset(&sa,0,sizeof(sa));
 281     sa.sin_family = AF_INET;
 282     sa.sin_port = htons(port);
 283     sa.sin_addr.s_addr = htonl(INADDR_ANY);
 284     if (bindaddr && inet_aton(bindaddr, &sa.sin_addr) == 0) {
 285         anetSetError(err, "invalid bind address");
 286         close(s);
 287         return ANET_ERR;
 288     }
 289     if (anetListen(err,s,(struct sockaddr*)&sa,sizeof(sa)) == ANET_ERR)
 290         return ANET_ERR;
 291     return s;
 292 }
 293
 294 int anetUnixServer(char *err, char *path)
 295 {
 296     int s;
 297     struct sockaddr_un sa;
 298
 299     if ((s = anetCreateSocket(err,AF_LOCAL)) == ANET_ERR)
 300         return ANET_ERR;
 301
 302     memset(&sa,0,sizeof(sa));
 303     sa.sun_family = AF_LOCAL;
 304     strncpy(sa.sun_path,path,sizeof(sa.sun_path)-1);
 305     if (anetListen(err,s,(struct sockaddr*)&sa,sizeof(sa)) == ANET_ERR)
 306         return ANET_ERR;
 307     return s;
 308 }
 309
 310 static int anetGenericAccept(char *err, int s, struct sockaddr *sa, socklen_t *len) {
 311     int fd;
 312     while(1) {
 313         fd = accept(s,sa,len);
 314         if (fd == -1) {
 315             if (errno == EINTR)
 316                 continue;
 317             else {
 318                 anetSetError(err, "accept: %s", strerror(errno));
 319                 return ANET_ERR;
 320             }
 321         }
 322         break;
 323     }
 324     return fd;
 325 }
 326
 327 int anetTcpAccept(char *err, int s, char *ip, int *port) {
 328     int fd;
 329     struct sockaddr_in sa;
 330     socklen_t salen = sizeof(sa);
 331     if ((fd = anetGenericAccept(err,s,(struct sockaddr*)&sa,&salen)) == ANET_ERR)
 332         return ANET_ERR;
 333
 334     if (ip) strcpy(ip,inet_ntoa(sa.sin_addr));
 335     if (port) *port = ntohs(sa.sin_port);
 336     return fd;
 337 }
 338
 339 int anetUnixAccept(char *err, int s) {
 340     int fd;
 341     struct sockaddr_un sa;
 342     socklen_t salen = sizeof(sa);
 343     if ((fd = anetGenericAccept(err,s,(struct sockaddr*)&sa,&salen)) == ANET_ERR)
 344         return ANET_ERR;
 345
 346     return fd;
 347 }