anet 网络操作函数 redis

#ifndef ANET_H
#define ANET_H

#define ANET_OK 0
#define ANET_ERR -1
#define ANET_ERR_LEN 256

/* Flags used with certain functions. */
#define ANET_NONE 0
#define ANET_IP_ONLY (1<<0)

#if defined(__sun)
#define AF_LOCAL AF_UNIX
#endif

int anetTcpConnect(char *err, char *addr, int port);
int anetTcpNonBlockConnect(char *err, char *addr, int port);
int anetUnixConnect(char *err, char *path);
int anetUnixNonBlockConnect(char *err, char *path);
int anetRead(int fd, char *buf, int count);
int anetResolve(char *err, char *host, char *ipbuf, size_t ipbuf_len);
int anetResolveIP(char *err, char *host, char *ipbuf, size_t ipbuf_len);
int anetTcpServer(char *err, int port, char *bindaddr, int backlog);
int anetTcp6Server(char *err, int port, char *bindaddr, int backlog);
int anetUnixServer(char *err, char *path, mode_t perm, int backlog);
int anetTcpAccept(char *err, int serversock, char *ip, size_t ip_len, int *port);
int anetUnixAccept(char *err, int serversock);
int anetWrite(int fd, char *buf, int count);
int anetNonBlock(char *err, int fd);
int anetEnableTcpNoDelay(char *err, int fd);
int anetDisableTcpNoDelay(char *err, int fd);
int anetTcpKeepAlive(char *err, int fd);
int anetPeerToString(int fd, char *ip, size_t ip_len, int *port);
int anetKeepAlive(char *err, int fd, int interval);
int anetSockName(int fd, char *ip, size_t ip_len, int *port);

#endif

#include "fmacros.h"

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <netdb.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>

#include "anet.h"

static void anetSetError(char *err, const char *fmt, ...)
{
va_list ap;

    if (!err)
  return;

    va_start(ap, fmt);
    vsnprintf(err, ANET_ERR_LEN, fmt, ap);
    va_end(ap);
}

int anetNonBlock(char *err, int fd)
{
int flags;

    /* Set the socket non-blocking.
     * Note that fcntl(2) for F_GETFL and F_SETFL can't be
     * interrupted by a signal. */
    if ((flags = fcntl(fd, F_GETFL)) == -1)
{
        anetSetError(err, "fcntl(F_GETFL): %s", strerror(errno));
        return ANET_ERR;
    }

    if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
{
        anetSetError(err, "fcntl(F_SETFL,O_NONBLOCK): %s", strerror(errno));
        return ANET_ERR;
    }
    return ANET_OK;
}

/* Set TCP keep alive option to detect dead peers. The interval option
* is only used for Linux as we are using Linux-specific APIs to set
* the probe send time, interval, and count. */
int anetKeepAlive(char *err, int fd, int interval)
{
int val = 1;

    if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &val, sizeof(val)) == -1)
    {
        anetSetError(err, "setsockopt SO_KEEPALIVE: %s", strerror(errno));
        return ANET_ERR;
    }

#ifdef __linux__

    /* Default settings are more or less garbage, with the keepalive time
     * set to 7200 by default on Linux. Modify settings to make the feature
     * actually useful. */

    /* Send first probe after interval. */
    val = interval;
    if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPIDLE, &val, sizeof(val)) < 0)
{
        anetSetError(err, "setsockopt TCP_KEEPIDLE: %s\n", strerror(errno));
        return ANET_ERR;
    }

    /* Send next probes after the specified interval. Note that we set the
     * delay as interval / 3, as we send three probes before detecting
     * an error (see the next setsockopt call). */
    val = interval/3;
    if (val == 0)
  val = 1;
    if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPINTVL, &val, sizeof(val)) < 0)
{
        anetSetError(err, "setsockopt TCP_KEEPINTVL: %s\n", strerror(errno));
        return ANET_ERR;
    }

    /* Consider the socket in error state after three we send three ACK
     * probes without getting a reply. */
    val = 3;
    if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPCNT, &val, sizeof(val)) < 0)
{
        anetSetError(err, "setsockopt TCP_KEEPCNT: %s\n", strerror(errno));
        return ANET_ERR;
    }
#endif

return ANET_OK;
}

static int anetSetTcpNoDelay(char *err, int fd, int val)
{
    if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof(val)) == -1)
    {
        anetSetError(err, "setsockopt TCP_NODELAY: %s", strerror(errno));
        return ANET_ERR;
    }
    return ANET_OK;
}

int anetEnableTcpNoDelay(char *err, int fd)
{
return anetSetTcpNoDelay(err, fd, 1);
}

int anetDisableTcpNoDelay(char *err, int fd)
{
return anetSetTcpNoDelay(err, fd, 0);
}

int anetSetSendBuffer(char *err, int fd, int buffsize)
{
    if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &buffsize, sizeof(buffsize)) == -1)
    {
        anetSetError(err, "setsockopt SO_SNDBUF: %s", strerror(errno));
        return ANET_ERR;
    }
    return ANET_OK;
}

int anetTcpKeepAlive(char *err, int fd)
{
    int yes = 1;
    if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &yes, sizeof(yes)) == -1)
{
        anetSetError(err, "setsockopt SO_KEEPALIVE: %s", strerror(errno));
        return ANET_ERR;
    }
    return ANET_OK;
}

/* anetGenericResolve() is called by anetResolve() and anetResolveIP() to
* do the actual work. It resolves the hostname "host" and set the string
* representation of the IP address into the buffer pointed by "ipbuf".
*
* If flags is set to ANET_IP_ONLY the function only resolves hostnames
* that are actually already IPv4 or IPv6 addresses. This turns the function
* into a validating / normalizing function. */
int anetGenericResolve(char *err, char *host, char *ipbuf, size_t ipbuf_len,
                       int flags)
{
    struct addrinfo hints, *info;
    int rv;

    memset(&hints,0,sizeof(hints));

    if (flags & ANET_IP_ONLY)
  hints.ai_flags = AI_NUMERICHOST;

    hints.ai_family = AF_UNSPEC;

    hints.ai_socktype = SOCK_STREAM; /* specify socktype to avoid dups */

    if ((rv = getaddrinfo(host, NULL, &hints, &info)) != 0)
{
        anetSetError(err, "%s", gai_strerror(rv));
        return ANET_ERR;
    }

    if (info->ai_family == AF_INET)
{
        struct sockaddr_in *sa = (struct sockaddr_in *)info->ai_addr;
        inet_ntop(AF_INET, &(sa->sin_addr), ipbuf, ipbuf_len);
    }
else
{
        struct sockaddr_in6 *sa = (struct sockaddr_in6 *)info->ai_addr;
        inet_ntop(AF_INET6, &(sa->sin6_addr), ipbuf, ipbuf_len);
    }

freeaddrinfo(info);
return ANET_OK;
}

int anetResolve(char *err, char *host, char *ipbuf, size_t ipbuf_len)
{
return anetGenericResolve(err,host,ipbuf,ipbuf_len,ANET_NONE);
}

int anetResolveIP(char *err, char *host, char *ipbuf, size_t ipbuf_len)
{
return anetGenericResolve(err,host,ipbuf,ipbuf_len,ANET_IP_ONLY);
}

static int anetSetReuseAddr(char *err, int fd)
{
    int yes = 1;
    /* Make sure connection-intensive things like the redis benckmark
     * will be able to close/open sockets a zillion of times */

    if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) == -1)
{
        anetSetError(err, "setsockopt SO_REUSEADDR: %s", strerror(errno));
        return ANET_ERR;
    }
    return ANET_OK;
}

static int anetCreateSocket(char *err, int domain)
{
    int s;
    if ((s = socket(domain, SOCK_STREAM, 0)) == -1)
{
        anetSetError(err, "creating socket: %s", strerror(errno));
        return ANET_ERR;
    }

    /* Make sure connection-intensive things like the redis benchmark
     * will be able to close/open sockets a zillion of times */
    if (anetSetReuseAddr(err,s) == ANET_ERR)
{
        close(s);
        return ANET_ERR;
    }
    return s;
}

#define ANET_CONNECT_NONE 0
#define ANET_CONNECT_NONBLOCK 1
static int anetTcpGenericConnect(char *err, char *addr, int port, int flags)
{
    int s = ANET_ERR, rv;
    char portstr[6]; /* strlen("65535") + 1; */
    struct addrinfo hints, *servinfo, *p;

    snprintf(portstr,sizeof(portstr),"%d",port);
    memset(&hints,0,sizeof(hints));
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;

    if ((rv = getaddrinfo(addr,portstr,&hints,&servinfo)) != 0)
{
        anetSetError(err, "%s", gai_strerror(rv));
        return ANET_ERR;
    }

    for (p = servinfo; p != NULL; p = p->ai_next)
{
        /* Try to create the socket and to connect it.
         * If we fail in the socket() call, or on connect(), we retry with
         * the next entry in servinfo. */

        if ((s = socket(p->ai_family,p->ai_socktype,p->ai_protocol)) == -1)
            continue;

        if (anetSetReuseAddr(err,s) == ANET_ERR)
   goto error;

        if (flags & ANET_CONNECT_NONBLOCK && anetNonBlock(err,s) != ANET_OK)
            goto error;

        if (connect(s,p->ai_addr,p->ai_addrlen) == -1)
  {
            /* If the socket is non-blocking, it is ok for connect() to
             * return an EINPROGRESS error here. */
            if (errno == EINPROGRESS && flags & ANET_CONNECT_NONBLOCK)
                goto end;

            close(s);

            s = ANET_ERR;

            continue;
        }

        /* If we ended an iteration of the for loop without errors, we
         * have a connected socket. Let's return to the caller. */
        goto end;

    }

    if (p == NULL)
        anetSetError(err, "creating socket: %s", strerror(errno));

error:

    if (s != ANET_ERR)
{
        close(s);
        s = ANET_ERR;
    }

end:

    freeaddrinfo(servinfo);

    return s;
}

int anetTcpConnect(char *err, char *addr, int port)
{
return anetTcpGenericConnect(err,addr,port,ANET_CONNECT_NONE);
}

int anetTcpNonBlockConnect(char *err, char *addr, int port)
{
return anetTcpGenericConnect(err,addr,port,ANET_CONNECT_NONBLOCK);
}

int anetUnixGenericConnect(char *err, char *path, int flags)
{
int s;
struct sockaddr_un sa;

if ((s = anetCreateSocket(err,AF_LOCAL)) == ANET_ERR)
return ANET_ERR;

    sa.sun_family = AF_LOCAL;

    strncpy(sa.sun_path,path,sizeof(sa.sun_path)-1);

    if (flags & ANET_CONNECT_NONBLOCK)
{
        if (anetNonBlock(err,s) != ANET_OK)
            return ANET_ERR;
    }

    if (connect(s,(struct sockaddr*)&sa,sizeof(sa)) == -1)
{
        if (errno == EINPROGRESS &&
            flags & ANET_CONNECT_NONBLOCK)
            return s;

        anetSetError(err, "connect: %s", strerror(errno));
        close(s);
        return ANET_ERR;
    }
    return s;
}

int anetUnixConnect(char *err, char *path)
{
return anetUnixGenericConnect(err,path,ANET_CONNECT_NONE);
}

int anetUnixNonBlockConnect(char *err, char *path)
{
return anetUnixGenericConnect(err,path,ANET_CONNECT_NONBLOCK);
}

/* Like read(2) but make sure 'count' is read before to return
* (unless error or EOF condition is encountered) */
int anetRead(int fd, char *buf, int count)
{
    int nread, totlen = 0;
    while(totlen != count)
{
        nread = read(fd,buf,count-totlen);

        if (nread == 0)
   return totlen;
        if (nread == -1)
   return -1;
        totlen += nread;
        buf += nread;
    }
    return totlen;
}

/* Like write(2) but make sure 'count' is read before to return
* (unless error is encountered) */
int anetWrite(int fd, char *buf, int count)
{
    int nwritten, totlen = 0;
    while(totlen != count)
{
        nwritten = write(fd,buf,count-totlen);

        if (nwritten == 0)
   return totlen;

        if (nwritten == -1)
   return -1;

        totlen += nwritten;
        buf += nwritten;
    }
    return totlen;
}

static int anetListen(char *err, int s, struct sockaddr *sa, socklen_t len, int backlog)
{
    if (bind(s,sa,len) == -1)
{
        anetSetError(err, "bind: %s", strerror(errno));
        close(s);
        return ANET_ERR;
    }

    if (listen(s, backlog) == -1)
{
        anetSetError(err, "listen: %s", strerror(errno));
        close(s);
        return ANET_ERR;
    }
    return ANET_OK;
}

static int anetV6Only(char *err, int s)
{
    int yes = 1;
    if (setsockopt(s,IPPROTO_IPV6,IPV6_V6ONLY,&yes,sizeof(yes)) == -1)
{
        anetSetError(err, "setsockopt: %s", strerror(errno));
        close(s);
        return ANET_ERR;
    }
    return ANET_OK;
}

static int _anetTcpServer(char *err, int port, char *bindaddr, int af, int backlog)
{
    int s, rv;
    char _port[6]; /* strlen("65535") */
    struct addrinfo hints, *servinfo, *p;

    snprintf(_port,6,"%d",port);
    memset(&hints,0,sizeof(hints));
    hints.ai_family = af;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_flags = AI_PASSIVE;    /* No effect if bindaddr != NULL */

    if ((rv = getaddrinfo(bindaddr,_port,&hints,&servinfo)) != 0)
{
        anetSetError(err, "%s", gai_strerror(rv));
        return ANET_ERR;
    }

    for (p = servinfo; p != NULL; p = p->ai_next)
{
        if ((s = socket(p->ai_family,p->ai_socktype,p->ai_protocol)) == -1)
            continue;

        if (af == AF_INET6 && anetV6Only(err,s) == ANET_ERR)
   goto error;

        if (anetSetReuseAddr(err,s) == ANET_ERR)
   goto error;

        if (anetListen(err,s,p->ai_addr,p->ai_addrlen,backlog) == ANET_ERR)
   goto error;

        goto end;
    }

    if (p == NULL)
{
        anetSetError(err, "unable to bind socket");
        goto error;
    }

error:
    s = ANET_ERR;
end:
    freeaddrinfo(servinfo);
    return s;
}

int anetTcpServer(char *err, int port, char *bindaddr, int backlog)
{
return _anetTcpServer(err, port, bindaddr, AF_INET, backlog);
}

int anetTcp6Server(char *err, int port, char *bindaddr, int backlog)
{
return _anetTcpServer(err, port, bindaddr, AF_INET6, backlog);
}

int anetUnixServer(char *err, char *path, mode_t perm, int backlog)
{
int s;
struct sockaddr_un sa;

if ((s = anetCreateSocket(err,AF_LOCAL)) == ANET_ERR)
return ANET_ERR;

    memset(&sa,0,sizeof(sa));
    sa.sun_family = AF_LOCAL;

    strncpy(sa.sun_path,path,sizeof(sa.sun_path)-1);

    if (anetListen(err,s,(struct sockaddr*)&sa,sizeof(sa),backlog) == ANET_ERR)
        return ANET_ERR;

    if (perm)
        chmod(sa.sun_path, perm);
    return s;
}

static int anetGenericAccept(char *err, int s, struct sockaddr *sa, socklen_t *len)
{
    int fd;
    while(1)
{
        fd = accept(s,sa,len);
        if (fd == -1)
  {
            if (errno == EINTR)
                continue;
            else
   {
                anetSetError(err, "accept: %s", strerror(errno));
                return ANET_ERR;
            }
        }
        break;
    }
    return fd;
}

int anetTcpAccept(char *err, int s, char *ip, size_t ip_len, int *port)
{
    int fd;

    struct sockaddr_storage sa;
    socklen_t salen = sizeof(sa);

    if ((fd = anetGenericAccept(err,s,(struct sockaddr*)&sa,&salen)) == ANET_ERR)
        return ANET_ERR;

    if (sa.ss_family == AF_INET)
{
        struct sockaddr_in *s = (struct sockaddr_in *)&sa;

        if (ip)
   inet_ntop(AF_INET,(void*)&(s->sin_addr),ip,ip_len);

        if (port)
   *port = ntohs(s->sin_port);
    }
else
{
        struct sockaddr_in6 *s = (struct sockaddr_in6 *)&sa;

        if (ip)
   inet_ntop(AF_INET6,(void*)&(s->sin6_addr),ip,ip_len);

        if (port)
   *port = ntohs(s->sin6_port);
    }
    return fd;
}

int anetUnixAccept(char *err, int s)
{
    int fd;
    struct sockaddr_un sa;
    socklen_t salen = sizeof(sa);

    if ((fd = anetGenericAccept(err,s,(struct sockaddr*)&sa,&salen)) == ANET_ERR)
        return ANET_ERR;

return fd;
}

int anetPeerToString(int fd, char *ip, size_t ip_len, int *port)
{
struct sockaddr_storage sa;
socklen_t salen = sizeof(sa);

    if (getpeername(fd,(struct sockaddr*)&sa,&salen) == -1)
{
        if (port) *port = 0;
        ip[0] = '?';
        ip[1] = '\0';
        return -1;
    }

    if (sa.ss_family == AF_INET)
{
        struct sockaddr_in *s = (struct sockaddr_in *)&sa;
        if (ip) inet_ntop(AF_INET,(void*)&(s->sin_addr),ip,ip_len);
        if (port) *port = ntohs(s->sin_port);
    }
else
{
        struct sockaddr_in6 *s = (struct sockaddr_in6 *)&sa;
        if (ip) inet_ntop(AF_INET6,(void*)&(s->sin6_addr),ip,ip_len);
        if (port) *port = ntohs(s->sin6_port);
    }
    return 0;
}

int anetSockName(int fd, char *ip, size_t ip_len, int *port)
{
struct sockaddr_storage sa;
socklen_t salen = sizeof(sa);

    if (getsockname(fd,(struct sockaddr*)&sa,&salen) == -1)
{
        if (port) *port = 0;
        ip[0] = '?';
        ip[1] = '\0';
        return -1;
    }

    if (sa.ss_family == AF_INET)
{
        struct sockaddr_in *s = (struct sockaddr_in *)&sa;

        if (ip)
   inet_ntop(AF_INET,(void*)&(s->sin_addr),ip,ip_len);

        if (port)
   *port = ntohs(s->sin_port);
    }
else
{
        struct sockaddr_in6 *s = (struct sockaddr_in6 *)&sa;
        if (ip)
   inet_ntop(AF_INET6,(void*)&(s->sin6_addr),ip,ip_len);

        if (port)
   *port = ntohs(s->sin6_port);
    }
    return 0;
}

anet 网络操作函数 redis

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