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更新： 我剛剛在有問題的函數中初始化了結構硬編碼，我仍然有錯誤！UDP sendto（）給出「無效的用戶空間地址」錯誤
void sendjoin(unsigned int ipaddress, unsigned short port, unsigned short preferredID){
printf("Sending join-request...\n");
char msg[9];
memset(msg, 0, 9);
msg[0] = JOIN_MASK | INTERN_MASK;
ipaddress = ipaddress;
port = port;
preferredID = htons(preferredID);
memcpy(&msg[1], &ipaddress, 4);
memcpy(&msg[5], &port, 2);
memcpy(&msg[7], &preferredID, 2);
errno = 0;
//printMSG((void *)&succAddr, sizeof(succAddr), 0);
socklen_t addrlen = sizeof(struct sockaddr_in);
struct sockaddr_in *temp = (struct sockaddr_in *) malloc(sizeof(struct sockaddr_in));
temp->sin_family = AF_INET;
temp->sin_port = htons((short)8888);
temp->sin_addr.s_addr = htonl(16777343);
if(0 > sendto(sock, msg, 9, 0, (struct sockaddr *)temp, addrlen)){
perror("Error while sending a packet.\n");
switch(errno){
case EFAULT:
printf("Invalid user space address.\n");
break;
case EAGAIN:
printf("Something with blocking.\n");
break;
case EBADF:
printf("Invalid descriptor.\n");
break;
case EINVAL:
printf("Invalid argument.\n");
break;
case EDESTADDRREQ:
printf("No Peer address.\n");
break;
case EISCONN:
printf("Connection mode socket.\n");
break;
case ENOTSOCK:
printf("The given socket is not a socket.\n");
break;
case ENOTCONN:
printf("No Target.\n");
break;
case ENOBUFS:
printf("Network output is full.\n");
break;
default:
printf("No spezific error.\n");
}
exit(1);
}
printf("Send to: %u %u\n", ntohl(succAddr.sin_addr.s_addr), ntohs(succAddr.sin_port));
}
我正在寫這個分佈式散列表服務器。這是一個超級簡單的版本。我只是剛剛起步，得到一個只是在聽包裝的服務器。另一個試圖加入第一個的dht網絡。所以我正在用一個端口號，家族AF_INET和一個IP地址填充全局struct sockaddr_in。
我使用函數inet_ntop（）將我的「localhost」 - 字符串轉換爲我的結構。 後來我使用sendto（）開始與dht網絡進行通信。但它只是給出了「無效的用戶空間地址」錯誤。 sendto（）獲取一個開放的套接字（自己的open serversocket！），一個初始化的緩衝區，他的長度，sockaddr_in結構體的地址和長度。
這是相當一些代碼。我刪除了一些未使用的函數，並試圖僅包含使用變量的函數。 在main（）中可以看到三個函數。一個是checkarguments（），這並不是很有趣。 然後你有setsocket（）函數，它讓我一個服務器套接字使用。在這個函數的最後，我填寫了這個的前任和後繼服務器的ip地址，端口和id。 然後你有試圖加入DHT網絡的letsgo（）函數。它使用已知的dht節點的地址填充全局struct sockaddr_in succAddr，因爲對sendjoin（）函數的調用總是發送給succAddr。 並在sendjoin（）它試圖發送到succAddr但失敗。我不知道爲什麼。我的succAddr被初始化，並且不應該指向一個無效的用戶空間？！
請幫助:)
這裏是我的代碼：
//=================================
//=Variablen=======================
//=================================
unsigned short myID = 0;
char *myIP= NULL;
char *myPORT = NULL;
char *nodeIP = NULL;
char *nodePORT = NULL;
int sock = 0;
struct sockaddr_in preAddr;
unsigned short preID = 0;
int preknown = 1;
struct sockaddr_in succAddr;
unsigned short succID = 0;
char packet[PACKETSIZE];
struct sockaddr_storage sender;
socklen_t sendersize = sizeof sender;
int tablefunctionstarted = 0;
char INTERN_MASK = 0b10000000;
char STABILIZE_MASK = 0b00000100;
char NOTIFY_MASK = 0b00000010;
char JOIN_MASK = 0b00000001;
char SNJ_MASK = 0b00000111;
//=================================
//=Functions=======================
//=================================
void setSocket();
int checkarguments(int argc, char **argv);
int letsgo();
void printMSG(char *msg, int msglength, int plain);
void handleintern(unsigned long msglength);
void handleoutside(unsigned long msglength);
void sendjoin(unsigned int ipaddress,unsigned short port, unsigned short preferredID);
void sendnotify(unsigned int ipaddress,unsigned short port, unsigned short preferredID);
void sendstabilize();
int main(int argc, char **argv){
printf("Starting server...\n");
int einklinken = checkarguments(argc, argv);
setSocket();
if(einklinken) if(letsgo()){ perror("Problem while joining DHT network!\n"); exit(2);};
/*
//Hauptpacketannahmeverarbeitungsschleife
long check = 0;
while(1){
printf("Server is waiting for packets... \n");
if(-1 == (check = recvfrom(sock, packet, PACKETSIZE, 0, (struct sockaddr *)&sender, &sendersize))){
perror("Error with new packet!\n");
exit(2);
}
printf("Found packet... \n");
//printMSG(packet, check, 1);
if(0 != (packet[0] & INTERN_MASK)) handleintern(check);
else handleoutside(check);
}
*/
}
int checkarguments(int argc, char **argv){
if(argc < 3){ fprintf(stderr,"Too few arguments! \nUsage: %s myip myport\nOptions:\n-id preferredID (Your preferred id in the DHT network.)\n-new ip port (IP address and port of a DHT network node.)", argv[0]); exit(1);}
if(argc > 8){ fprintf(stderr,"Too many arguments! \nUsage: %s myip myport\nOptions:\n-id preferredID (Your preferred id in the DHT network.)\n-new ip port (IP address and port of a DHT network node.)", argv[0]); exit(1);}
/* printf("Arguments:\n");
for(int i = 0; i < argc; ++i){
printf("%s\n", argv[i]);
} */
printf("Parsing arguments...\n");
myIP = argv[1];
myPORT = argv[2];
printf("My ip: %s\n", myIP);
printf("My port: %s\n", myPORT);
int newNode = 0;
int count = 3;
while(argc > count){
if(argv[count][0]!='-'){fprintf(stderr,"Wrong usage! \nUsage: %s myip myport\nOptions:\n-id preferredID (Your preferred id in the DHT network.)\n-new ip port (IP address and port of a DHT network node.)", argv[0]); exit(1);}
if(argv[count][1]=='i'){
++count;
errno = 0;
long value = 0;
value = strtol(argv[count++], NULL, 10);
switch(errno){
case ERANGE:
printf("The ID could not be represented.\n");
exit(1);
case EINVAL:
printf("Unsupported base/radix.\n");
exit(1);
}
if(value > 65536){ perror("Your desired ID is over the max value of 65536!\n"); exit(1);}
myID = (short) value;
printf("My id: %u\n", myID);
}
else if(argv[count][1]=='n'){
++count;
nodeIP = argv[count++];
nodePORT = argv[count++];
printf("The nodes ip: %s\n", nodeIP);
printf("The nodes port: %s\n", nodePORT);
newNode = 1;
}
}
printf("Finished parsing arguments.\n");
return newNode;
}
void setSocket(){
printf("Configuring the socket...\n");
struct addrinfo hints, *locations, *p;
int yes=1;
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_flags = AI_PASSIVE;
int rv = getaddrinfo(NULL, myPORT, &hints, &locations);
if(rv != 0){
fprintf(stderr, "getaddrinfo threw an error! Maybe your port is used?\n");
exit(1);
}
for(p = locations; p!=NULL; p=p->ai_next){
sock = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
if(sock == -1){perror("SocketError");continue;}
if(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) == -1){perror("Can't clean socket!\n"); exit(1);}
if(bind(sock, p->ai_addr, p->ai_addrlen) == -1){perror("BindError");close(sock);continue;}
break;
}
if(p==NULL){
perror("Failed to bind!\n");
exit(2);
}
int check = 0;
if(-1 == (check = inet_pton(AF_INET, myIP, &(preAddr.sin_addr)))){ perror("Wrong ip format!\n"); exit(1);}
if(-1 == (check = inet_pton(AF_INET, myIP, &(succAddr.sin_addr)))){ perror("Wrong ip format!\n"); exit(1);}
memcpy(&(succAddr.sin_port), &(((struct sockaddr_in *)p->ai_addr)->sin_port), 2);
memcpy(&(preAddr.sin_port), &(((struct sockaddr_in *)p->ai_addr)->sin_port), 2);
memset(preAddr.sin_zero, 0, 8);
memset(succAddr.sin_zero, 0, 8);
preID = myID;
succID = myID;
printf("Finished configuring the socket.\n");
freeaddrinfo(locations);
}
int letsgo(){
printf("Trying to join an existent DHT network...\n");
preknown = 0;
int check = 0;
succAddr.sin_family = AF_INET;
if(-1 == (check = inet_pton(AF_INET, nodeIP, &(succAddr.sin_addr)))){ perror("Wrong ip format!\n"); exit(1);}
errno = 0;
long value = 0;
value = strtol(nodePORT, NULL, 10);
switch(errno){
case ERANGE:
printf("The node port could not be represented.\n");
exit(1);
case EINVAL:
printf("Unsupported base/radix.\n");
exit(1);
}
if(value > 65536){ perror("Your node port is over the max value of 65536!\n"); exit(1);}
succAddr.sin_port = htons((short) value);
unsigned int ipaddress = preAddr.sin_addr.s_addr;
unsigned short port = preAddr.sin_port;
unsigned short preferredID = 0;
sendjoin(ipaddress, port, myID);
while(1){
printf("Wait for notify answer... \n");
if(-1 == (check = recvfrom(sock, packet, PACKETSIZE, 0, (struct sockaddr *)&sender, &sendersize))){
perror("Error with new packet!\n");
exit(2);
}
printf("Got answer... \n");
if(0 == (packet[0] & INTERN_MASK)){ printf("Can't understand the packet.\n"); continue;}
if(0 == (packet[0] & NOTIFY_MASK || check < 8)){ printf("Not a notify packet.\n"); continue;}
memcpy(&preferredID, &packet[7], 2);
preferredID = ntohs(preferredID);
if(preferredID > TABLE_LENGTH){ perror("Preferred id is too big!\n"); continue;}
memcpy(&ipaddress, &packet[1], 4);
memcpy(&port, &packet[5], 2);
succAddr.sin_addr.s_addr = ipaddress;
succAddr.sin_port = port;
succID = preferredID;
break;
}
return 0;
}
void sendjoin(unsigned int ipaddress, unsigned short port, unsigned short preferredID){
printf("Sending join-request...\n");
char msg[9];
memset(&msg, 0, 9);
msg[0] = JOIN_MASK | INTERN_MASK;
ipaddress = ipaddress;
port = port;
preferredID = htons(preferredID);
memcpy(&msg[1], &ipaddress, 4);
memcpy(&msg[5], &port, 2);
memcpy(&msg[7], &preferredID, 2);
errno = 0;
//printMSG((void *)&succAddr, sizeof(succAddr), 0);
socklen_t addrlen = sizeof(struct sockaddr_in);
if(0 > sendto(sock, msg, 9, 0, (struct sockaddr *)&succAddr, addrlen)){
perror("Error while sending a packet.\n");
switch(errno){
case EFAULT:
printf("Invalid user space address.\n");
break;
case EAGAIN:
printf("Something with blocking.\n");
break;
case EBADF:
printf("Invalid descriptor.\n");
break;
case EINVAL:
printf("Invalid argument.\n");
break;
case EDESTADDRREQ:
printf("No Peer address.\n");
break;
case EISCONN:
printf("Connection mode socket.\n");
break;
case ENOTSOCK:
printf("The given socket is not a socket.\n");
break;
case ENOTCONN:
printf("No Target.\n");
break;
case ENOBUFS:
printf("Network output is full.\n");
break;
default:
printf("No spezific error.\n");
}
exit(1);
}
printf("Send to: %u %u\n", ntohl(succAddr.sin_addr.s_addr), ntohs(succAddr.sin_port));
}
'PERROR（）'已經打印錯誤的正確文本。根本不需要那個巨大的開關語句，特別是當它打印*錯誤的*文本時。不要'翻譯'系統錯誤代碼或消息。否則你冒着給出錯誤信息的風險，只有你可以調試代碼。 – EJP
您是否嘗試過使用'strace'來確認sendto（）'的參數是否正確？ –
@EJP我只從'perror（）'得到了「壞地址」作爲錯誤描述，我在因特網上找到的errno手冊頁用「無效的用戶空間地址」指定它。但是，是的，我將在未來停止這樣做:)。 我仍然不知道錯誤是什麼。但是今天，我在ubuntu 14上測試了我的程序，並沒有給出任何錯誤。這與我的cygwin在Windows上有關。 – Hyrikan