int connect_host(s_host_t * h, int recv_sec, int send_sec)
{
int sock = -1;
int ret;
int select_ret;
int res;
socklen_t res_size = sizeof res;
struct sockaddr_in channel;
struct hostent host;
struct timeval recv_timeout;
struct timeval send_timeout;
fd_set wset;
if (FAIL_CHECK(!gethostname_my(h->addr, &host)))
{
gko_log(WARNING, "gethostbyname %s error", h->addr);
ret = -1;
goto CONNECT_END;
}
sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (FAIL_CHECK(sock < 0))
{
gko_log(WARNING, "get socket error");
ret = -1;
goto CONNECT_END;
}
recv_timeout.tv_usec = 0;
recv_timeout.tv_sec = recv_sec ? recv_sec : RCV_TIMEOUT;
send_timeout.tv_usec = 0;
send_timeout.tv_sec = send_sec ? send_sec : SND_TIMEOUT;
memset(&channel, 0, sizeof(channel));
channel.sin_family = AF_INET;
memcpy(&channel.sin_addr.s_addr, host.h_addr, host.h_length);
channel.sin_port = htons(h->port);
/** set the connect non-blocking then blocking for add timeout on connect **/
if (FAIL_CHECK(setnonblock(sock) < 0))
{
gko_log(WARNING, "set socket non-blocking error");
ret = -1;
goto CONNECT_END;
}
/** connect and send the msg **/
if (FAIL_CHECK(connect(sock, (struct sockaddr *) &channel, sizeof(channel)) &&
errno != EINPROGRESS))
{
gko_log(WARNING, "connect error");
ret = HOST_DOWN_FAIL;
goto CONNECT_END;
}
/** Wait for write bit to be set **/
///
FD_ZERO(&wset);
FD_SET(sock, &wset);
select_ret = select(sock + 1, 0, &wset, 0, &send_timeout);
if (select_ret < 0)
{
gko_log(FATAL, "select error on connect");
ret = HOST_DOWN_FAIL;
goto CONNECT_END;
}
if (!select_ret)
{
gko_log(FATAL, "connect timeout on connect");
ret = HOST_DOWN_FAIL;
goto CONNECT_END;
}
/**
* check if connection is RESETed, maybe this is the
* best way to do that
* SEE: http://cr.yp.to/docs/connect.html
**/
(void) getsockopt(sock, SOL_SOCKET, SO_ERROR, &res, &res_size);
if (CONNECT_DEST_DOWN(res))
{
gko_log(NOTICE, "dest is down SO_ERROR: %d", res);
ret = HOST_DOWN_FAIL;
goto CONNECT_END;
}
///gko_log(WARNING, "selected %d ret %d, time %d", sock, select_ret, send_timeout.tv_sec);
/** set back blocking **/
if (FAIL_CHECK(setblock(sock) < 0))
{
gko_log(WARNING, "set socket non-blocking error");
ret = -1;
goto CONNECT_END;
}
/** set recv & send timeout **/
if (FAIL_CHECK(setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, (char *) &recv_timeout,
sizeof(struct timeval))))
{
gko_log(WARNING, "setsockopt SO_RCVTIMEO error");
ret = -1;
goto CONNECT_END;
}
if (FAIL_CHECK(setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, (char *) &send_timeout,
sizeof(struct timeval))))
{
gko_log(WARNING, "setsockopt SO_SNDTIMEO error");
ret = -1;
goto CONNECT_END;
}
ret = sock;
CONNECT_END:
///
if (ret < 0 && sock >= 0)
{
close_socket(sock);
}
return ret;
}
gethostname_my：
struct hostent * gethostname_my(const char *host, struct hostent * ret)
{
struct hostent * tmp;
if (!ret)
{
gko_log(FATAL, "Null buf passed to gethostname_my error");
return (struct hostent *) NULL;
}
pthread_mutex_lock(&g_netdb_mutex);
tmp = gethostbyname(host);
if (tmp)
{
memcpy(ret, tmp, sizeof(struct hostent));
}
else
{
gko_log(WARNING, "resolve %s failed", host);
ret = NULL;
}
pthread_mutex_unlock(&g_netdb_mutex);
return ret;
}
上面的func是“memcpy（＆amp; channel.sin_addr.s_addr，host.h_addr，host.h_length）;”几次。 怎么可能??? gdb说它被信号11终止了
#0 0x000000302af71900 in memcpy () from /lib64/tls/libc.so.6
(gdb) bt
#0 0x000000302af71900 in memcpy () from /lib64/tls/libc.so.6
#1 0x000000000040c42f in connect_host (h=0x2cd13ee060, recv_sec=2, send_sec=2) at socket.cpp:121
#2 0x0000000000409f65 in sendcmd (h=0x2cd13ee060, cmd=0x2a9bcf4fb0 "DELE\t127.0.0.1\t59968", recv_sec=2, send_sec=2) at gingko_base.cpp:643
#3 0x000000000040685e in quit_job_s (uri=0x2cd13ed170, fd=1015) at gingko_common.h:550
#4 0x0000000000403e48 in conn_send_data (fd=1015, str=0x2cd13ed170, len=8) at async_conn.cpp:281
#5 0x0000000000404045 in conn_tcp_server_on_data (fd=1015, ev=2, arg=0x1d51a00) at async_conn.cpp:358
#6 0x000000000040f537 in event_base_loop (base=0x7b1ab0, flags=0) at event.c:392
#7 0x00000000004034cf in thread_worker_init (arg=0x7b1a00) at async_threads.cpp:84
#8 0x000000302b80610a in start_thread () from /lib64/tls/libpthread.so.0
#9 0x000000302afc6003 in clone () from /lib64/tls/libc.so.6
#10 0x0000000000000000 in ?? ()
(gdb) f 1
#1 0x000000000040c42f in connect_host (h=0x2cd13ee060, recv_sec=2, send_sec=2) at socket.cpp:121
121 memcpy(&channel.sin_addr.s_addr, host.h_addr, host.h_length);
(gdb) p host
$1 = {h_name = 0x2ccd100d08 "127.0.0.1", h_aliases = 0x2ccd100d00, h_addrtype = 2, h_length = 4, h_addr_list = 0x2ccd100cf0}
(gdb) p &channel.sin_addr.s_addr
$2 = (in_addr_t *) 0x2a9bcf4f04
(gdb) p channel
$3 = {sin_family = 2, sin_port = 0, sin_addr = {s_addr = 0}, sin_zero = "\000\000\000\000\000\000\000"}
(gdb) p host.h_addr_list[0]
$5 = 0x2ccd100ce0 "\177"
(gdb) p host.h_addr_list[0][0]
$6 = 127 '\177'
(gdb) p host.h_addr_list[0][1]
$7 = 0 '\0'
(gdb) p host.h_addr_list[0][2]
$8 = 0 '\0'
(gdb) p host.h_addr_list[0][3]
$9 = 1 '\001'
答案 0 :(得分：2)
您正在呼叫gethostname_my，但尚未提供其定义。
我会说它调用gethostname并返回hostent结构的副本。
但请注意，h_addr是一个扩展为h_addr_list[0]的宏，因此如果gethostname_my函数未正确复制列表，则无效。
<强>澄清：
gethostname不可重入。它使用全局静态内存块来返回数据。该数据包含hostent结构和可变数量的别名和地址。它们通常是，但不一定是这个结构的旁边。
如果您正在尝试制作此函数的可重入版本，那么您应该：
hostent struct 以及此结构所指向的所有别名和地址。但是，当你拥有（不是那么）新的和改进的getaddrinfo函数时，为什么还要烦恼？这是可重入的，只是做了紧的事（tm）。
答案 1 :(得分：1)
h_addr是char *，如下所示，保存主机的IP地址。所以长度可以是最多15个字节。
struct hostent
{
char *h_name; /* Official name of host. */
char **h_aliases; /* Alias list. */
int h_addrtype; /* Host address type. */
int h_length; /* Length of address. */
char **h_addr_list; /* List of addresses from name server. */
#define h_addr h_addr_list[0] /* Address, for backward compatibility. */
};
而s_addr是4个字节。最有可能h_addr长度超过4个字节并导致核心转储
答案 2 :(得分：0)
字段
s_addr
是一个很长的（我猜8个字节？）
您正在复制
host.h_length
字节。在失败的情况下，h_length的值是多少？