Socket编程：SENDTO总是失败，错误号22

问题描述

我总是得到这个code发送，22（无效参数）的错误号没有字节。在 destination_host 设置别处称为是有效的，所以我真的不明白是怎么回事。 MAXMSGSIZE 是1000没有错误，或警告。我与 -Wall -pedantic -Werror

编译

 的char * data_rec;
u_int DATA_LEN;INT的sockfd;
uint16_t *纳秒;
结构sockaddr_in的地址;
结构sockaddr *地址;字符* IP;INT I;
INT错误号;
INT bytes_sent;DATA_LEN = MAXMSGSIZE;
data_rec =的malloc（sizeof的（char）的* MAXMSGSIZE）;
NS =的malloc（MAXMSGSIZE *的sizeof（uint16_t））;
IP =的malloc（MAXMSGSIZE *的sizeof（字符））;data_rec =一些随机测试的东西;的sockfd =插座（PF_INET，SOCK_DGRAM，IPPROTO_UDP）;
如果（的sockfd℃，）{
    的printf（插座（）失败\\ n）;
}inet_ntop（AF_INET，destination_host-＆GT; h_addr，IP，MAXMSGSIZE）;
memset的（安培;地址，0，sizeof的（地址））;
address.sin_family = AF_INET;
address.sin_port = htons（theirPort）;
address.sin_addr.s_addr =（无符号长）知识产权;地址=（结构sockaddr *）及地址;
绑定（的sockfd，地址，的sizeof（地址））;
/ *转换为uint16_t消息* /
对于（i = 0; I＆LT; MAXMSGSIZE;我++）{
    NS [I] = htons（data_rec [I]）;
}
/ *发送消息* /
bytes_sent = SENDTO（的sockfd，NS，DATA_LEN，MSG_DONTWAIT，地址，的sizeof（地址））;
如果（bytes_sent == -1）{
    的printf（发送错误：％I \\ N，错误号）;
}
 

解决方案

你给的地址错误的大小。 地址是一个真正的结构SOCKADDR_IN ，而不是结构sockaddr

中的sendto的最后一个参数更改为的sizeof（地址）

I am always getting no bytes sent, with an errno of 22 (Invalid Argument) with this code. The destination_host is set elsewhere and known to be valid, so I really don't see what is going on. MAXMSGSIZE is 1000. No errors, or warnings. I am compiling with -Wall -Werror -pedantic

char *data_rec;
u_int data_len;

int sockfd;
uint16_t *ns;
struct sockaddr_in address;
struct sockaddr *addr;

char *ip;

int i;
int errno;
int bytes_sent;

data_len = MAXMSGSIZE;
data_rec = malloc(sizeof(char)*MAXMSGSIZE);
ns = malloc(MAXMSGSIZE*sizeof(uint16_t));
ip = malloc(MAXMSGSIZE*sizeof(char));

data_rec = "some random test stuff";

sockfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
if(sockfd<0) {
    printf("socket() failed\n");
}

inet_ntop(AF_INET,destination_host->h_addr,ip,MAXMSGSIZE);
memset(&address, 0, sizeof(address));
address.sin_family = AF_INET;
address.sin_port = htons(theirPort);
address.sin_addr.s_addr = (unsigned long)ip;

addr = (struct sockaddr*)&address;
bind(sockfd,addr,sizeof(address));
/*Convert the message to uint16_t*/
for(i=0; i<MAXMSGSIZE; i++) {
    ns[i] = htons(data_rec[i]);
}


/* send the message */
bytes_sent = sendto(sockfd, ns, data_len, MSG_DONTWAIT, addr, sizeof(addr));
if(bytes_sent == -1) {
    printf("Error sending: %i\n",errno);
}

解决方案

You're giving the wrong size for the address. addr is really a struct sockaddr_in, not a struct sockaddr.

Change the last parameter of sendto to sizeof(address)

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