C中的套接字连接错误
此服务器的目标是以相对简单的方式传输小文件。我已经完成了代码，所有代码都编译成功了，当我尝试运行它时，服务器端没有问题，但是客户端在套接字绑定中给出了一个错误和一个分段错误。我想知道代码中的什么导致了这些问题 服务器：C中的套接字连接错误,c,sockets,server,C,Sockets,Server,此服务器的目标是以相对简单的方式传输小文件。我已经完成了代码，所有代码都编译成功了，当我尝试运行它时，服务器端没有问题，但是客户端在套接字绑定中给出了一个错误和一个分段错误。我想知道代码中的什么导致了这些问题 服务器： #include <stdio.h> #include <sys/socket.h> #include <sys/stat.h> #include <sys/fcntl.h> #include <string.h> #i
#include <stdio.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/fcntl.h>
#include <string.h>
#include <unistd.h>
#include <crypt.h>
#include <time.h>
#include <stdlib.h>
#include <sys/types.h>
#include <dirent.h>
#include <netinet/ip.h>
void timestamp_ss()
{
time_t current_time;
char* log_time;
log_time = ctime(¤t_time);
log_file_ss(log_time);
}
send_data(int sockfd, char info_to_send)
{
char eof_buffer[4] = "\EOF";
int sent_data, data_to_send;
data_to_send = strlen(&info_to_send);
while(data_to_send > 0)
{
sent_data = send(sockfd, &info_to_send, data_to_send, 0);
if(sent_data == -1)
perror("There was a problem in the sending of data!");
data_to_send -= sent_data;
info_to_send += sent_data;
}
send(sockfd, eof_buffer, 4, 0);
}
int recv_data(int sockfd, char *dest_buffer)
{
#define EoF "\EOF"
unsigned char *buffer;
int eof_match = 0, eof_size = 2;
buffer = dest_buffer;
while(recv(sockfd, buffer, 1, 0) == 1)
{
if(*buffer == EoF[eof_match])
{
eof_match++;
if(eof_match = eof_size)
{
*(buffer+1-eof_size) = '\0';
return strlen(dest_buffer);
}
else
{
eof_match = 0;
}
}
buffer++;
}
return 0;
}
int password_ss(char *password_attempt, char *password_actual)
{
char key[] = { "ZjQXStSi" };
char ivec[] = {"7eNP3U1b" };
char des_dec[] = { "DES_DECRYPT" };
char des_hw[] = { "DES_HW" };
int l, i;
l = strlen(password_attempt);
i = cbc_crypt(key, password_attempt, l, *des_dec | *des_hw, ivec);
if(i < 0)
error_escape("In decryption");
if(password_attempt == password_actual)
return 1;
else
return 0;
}
int log_file_ss(char *log_message)
{
char logfile[]= "/Server/log/C-File-Transfer-Server-Log";
int log_fd, len;
log_fd = open(logfile, O_WRONLY | O_APPEND | O_CREAT);
len = strlen(log_message);
write(log_fd, log_message, len);
}
void file_to_client_ss(int sockfd, struct sockaddr_in *client_addr_ptr)
{
char file_req_c[128];
char buffer[10000];
char files[256];
char pass_attempt[128];
char *error_403[20] = { "Error 403: Forbidden" };
char *error_404[25] = { "Error 404: File Not Found" };
char *pass_path[20] = { "/server/log/PASSWORD" };
char *pass_req[50] = { "This File Requires A Password, Please Enter It Now" };
char *no_pass[37] = { "This File Does Not Require A Password" };
char *username;
char *file_s;
char *string;
char *file1_path[26] = { "/server/received_files/r_w" };
char *file2_path[24] = { "/server/received_files/r" };
char *file3_path[24] = { "/server/received_files/n" };
char file_data;
FILE *cs, *ps;
int file1, file2, file3, file_test, pass;
cs = fopen(file_req_c, "r");
recv_data(sockfd, username);
chdir("/server/log/PASSWORD");
ps = fopen(username, "r");
fread(files, 1, file_size(ps), ps);
chdir("/server");
recv_data(sockfd, file_req_c);
file_test = file_exist(file1_path, file_req_c);
if(file_test = -1)
{
file_test = file_exist(file2_path, file_req_c);
if(file_test = -1)
{
file_test = file_exist(file3_path, file_req_c);
if(file_test = -1)
{
error_escape("Opening file request from client");
}
else
{
send_data(sockfd, **pass_req);
recv_data(sockfd, pass_attempt);
pass = password_ss(pass_attempt, files);
if(pass == 0)
{
send_data(sockfd, **error_403);
error_escape("Wrong Password");
}
else
{
if(file_exist(pass_path, username) == 0)
send_data(sockfd, *file_req_c);
else
errror_escape("Error in sending file");
}
}
}
else
{
chdir(*file2_path);
file_data = fread(buffer, 1, file_size(cs), cs);
send_data(sockfd, **no_pass);
send_data(sockfd, file_data);
}
}
else
{
chdir(*file1_path);
file_data = fread(buffer, 1, file_size(cs), cs);
send_data(sockfd, **no_pass);
send_data(sockfd, file_data);
}
}
int file_size(FILE *stream)
{
off_t file_len;
fseek(stream, 0, SEEK_END);
file_len = ftell(stream);
fclose(stream);
return file_len;
}
int file_exist(char *file_path, char *file_name)
{
DIR *dp;
FILE *fc;
struct dirent *ep;
dp = opendir(file_path);
if(dp == NULL)
perror("Opening path");
else
chdir(file_path);
closedir(dp);
fc = fopen(file_name, "r");
if(fc == NULL)
{
perror("Opening file");
return(-1);
}
else {
return(0);
}
}
error_escape(char *problem)
{
char error_message[256];
strcpy(error_message, "! There Has Been An Error !");
strncat(error_message, problem, 173);
perror("Error: ");
log_file_ss(error_message);
timestamp_ss();
exit(-1);
}
void file_accept_ss(int sockfd, struct sockaddr_in *client_addr_ptr)
{
char client_request[512], username[256], file_content[8192], buf[8192];
char *client_r_w[26] = { "/server/received_files/r_w" };
char *client_r[24] = { "/server/received_files/r" };
char *client_n[24] = { "/server/received_files/n" };
char *search_string_read[6] = { "O_READ" };
char *search_string_w[14] = { "O_READANDWRITE" };
char *password_path[20] = { "/server/log/PASSWORD" };
char *mkdir[37] = { "/server/log/PASSWORD" };
char *ret;
char file_data, recv_i;
char password[256];
int change_dir_test, recv_check;
FILE *fn, *Ps;
recv_data(sockfd, username);
recv_data(sockfd, password);
strcat(*mkdir, username);
strcat(*mkdir, password);
fn = fopen(*mkdir, "a");
chdir(*password_path);
Ps = fopen(*mkdir, "a");
chdir("/server");
recv_i = fread(buf, 1, file_size(fn), fn);
recv_check = recv_data(sockfd, &recv_i);
if(recv_check = -1)
error_escape("! There Was An Error In The Receiving Of The File From The Client !");
fread(file_content, 8, file_size(fn), fn);
ret = strstr(file_content, *search_string_read);
if(ret = NULL)
{
change_dir_test = chdir(*client_n);
if(change_dir_test = -1)
error_escape("! There Was An Error In The Changing Of Directories !");
else
{
file_data = fread(buf, 1, file_size(Ps), Ps);
recv_data(sockfd, &file_data);
chdir(*client_n);
strcat(*client_n, username);
rename(username, *client_n);
}
}
if(ret = *search_string_read)
{
change_dir_test = chdir(*client_r);
if(change_dir_test = -1)
error_escape("! There Was An Error In The Changing Of Directories !");
else
{
chdir(*client_r);
rename(username, *client_r);
}
}
if(ret = *search_string_w)
{
change_dir_test = chdir(*client_r_w);
if(change_dir_test = -1)
error_escape("! There Was An Error In The Changing Of Directories !");
else
{
chdir(*client_r_w);
rename(username, *client_r_w);
}
}
log_file_ss("Client:");
log_file_ss(username);
timestamp_ss();
}
int main(void)
{
struct sockaddr_in server, client;
int sockfd, bind_test, listen_test, client_sockfd, sin_size;
sockfd = socket(PF_INET, SOCK_STREAM, 0);
if(sockfd == -1)
error_escape("Making Socket");
server.sin_family = AF_INET;
server.sin_port = htons(80);
server.sin_addr.s_addr = INADDR_ANY;
bind_test = bind(sockfd, (struct sockaddr *)&server, sizeof(server));
if(bind_test < 0)
error_escape("Binding Socket");
listen_test = listen(sockfd, 20);
if(listen_test < 0)
error_escape("Listening");
while(1)
{
sin_size = sizeof(struct sockaddr_in);
client_sockfd = accept(sockfd, (struct sockaddr *)&client, &sin_size);
file_accept_ss(client_sockfd, &client);
file_to_client_ss(client_sockfd, &client);
}
shutdown(client_sockfd, SHUT_RDWR);
return 0;
}
#include <stdio.h>
#include <string.h>
#include <dirent.h>
#include <sys/types.h>
#include <unistd.h>
#include <crypt.h>
#include <sys/socket.h>
#include <netinet/ip.h>
send_data(int sockfd, char info_to_send)
{
char eof_buffer[4] = "\EOF";
int sent_data, data_to_send;
data_to_send = strlen(&info_to_send);
while(data_to_send > 0)
{
sent_data = send(sockfd, &info_to_send, data_to_send, 0);
if(sent_data == -1)
perror("There was a problem in the sending of data!");
data_to_send -= sent_data;
info_to_send += sent_data;
}
send(sockfd, eof_buffer, 4, 0);
}
send_file_cs(int sockfd)
{
char file_buffer[4096], file_name[256];
char name, username, password;
char *search_st, file_data, *file_location;
int perm_choice, password_max = 20, ch;
off_t size_of_file;
FILE *fp;
printf("%s\n", "Please enter the path to file you would like to move to server:");
scanf("%s", &file_location);
ch = chdir(file_location);
if(ch == -1)
perror("! There Has Been An Error In The Directory Path !");
else
chdir(file_location);
printf("%s\n", "Now Enter The Name Of The File You Would Like To Transfer:");
printf("%s\n", "! Warning, The File May Not Exceed 4 kilobytes !");
scanf("%s", &name);
printf("%s", "What would you like the username for this file to be?");
name = *file_name;
size_of_file = file_size(fp);
if(size_of_file > 4096)
printf("! The File Is Greater Than 4 Kilobytes !");
fp = fopen(file_name, "r+");
printf("%s\n", "What Permissions Would You Like The File To Have?\n (1) For Other Clients To See The File\n (2) For Other CLients To See But Not Be Able To Access\n (3) Other Clients Cannot See Or Access The File");
scanf("%d", &perm_choice);
if(perm_choice > 3 || perm_choice < 1)
perror("! Incorrect Permissions !");
if(perm_choice = 1)
{
search_st = "O_READ";
fopen(file_name, "a");
fwrite(search_st, 1, strlen(search_st), fp);
}
if(perm_choice = 2)
{
search_st = "O_READANDWRITE";
fopen(file_name, "a");
fwrite(search_st, 1, strlen(search_st), fp);
}
if(perm_choice = 3)
{
search_st = "O_NOACCESS";
fopen(file_name, "a");
fwrite(search_st, 1, strlen(search_st), fp);
printf("%s", "Please enter a password");
scanf("%s", &password);
send_data(sockfd, password);
}
file_data = fread(file_buffer, 1, 4096, fp);
send_data(sockfd, file_data);
}
int recv_data(int sockfd, char *dest_buffer)
{
#define EoF "\EOF"
unsigned char *buffer;
int eof_match = 0, eof_size = 2;
buffer = dest_buffer;
while(recv(sockfd, buffer, 1, 0) == 1)
{
if(*buffer == EoF[eof_match])
{
eof_match++;
if(eof_match = eof_size)
{
*(buffer+1-eof_size) = '\0';
return strlen(dest_buffer);
}
else
{
eof_match = 0;
}
}
buffer++;
}
return 0;
}
int password_cs(int max_length, int sockfd)
{
char salt[] = { "ZjQXStSi" };
char ivec[] = { "7eNP3U1b" };
char des_enc[] = { "DES_ENCRYPT" };
char des_hw[] = { "DES_HW" };
char password;
char *ret, *ret2;
int l, i;
printf("%s", "Please set your password:");
scanf("%s", &password);
l = strlen(&password);
if(l > max_length)
printf("%s : %d", "Password must be less than", max_length);
i = cbc_crypt(salt, password, l, *des_enc | *des_hw, ivec);
if(i < 0)
perror("In erncryption");
send_data(sockfd, password);
return 0;
}
int file_size(FILE *stream)
{
off_t file_len;
fseek(stream, 0, SEEK_END);
file_len = ftell(stream);
fclose(stream);
return file_len;
}
int file_exist(char *file_path, char *file_name)
{
DIR *dp;
FILE *fc;
struct dirent *ep;
dp = opendir(file_path);
if(dp == NULL)
perror("Opening path");
else
chdir(file_path);
closedir(dp);
fc = fopen(file_name, "r");
if(fc == NULL)
{
perror("Opening file");
return(-1);
}
else {
return(0);
}
}
void client_request_file_cs(int sockfd)
{
char password_buf[128], file[4096], recv_file[256];
char *requires[16] = { "Requires" };
char *str, *restr, *file_contents, *name2, *path, *rebuf;
char file_req, password, name, username;
int test;
FILE *re;
printf("%s\n", "What file would you like from the server?");
scanf("%s", &file_req);
printf("%s", "What is the user name associated with the file?");
scanf("%s", &username);
send_data(sockfd, username);
printf("%s\n", "Where Would You Like The File To Be Put, Please Enter The Path:");
scanf("%s", &path);
test = chdir(path);
if(test == -1)
printf("%s\n", "Invalid Path");
printf("%s\n", "What Would You Like To Call The File?");
scanf("%s", &name);
name2 = &name;
re = fopen(name2, "w");
fread(file_contents, 1, file_size(re), re);
send_data(sockfd, file_req);
recv_data(sockfd, password_buf);
printf("%s\n", password_buf);
str = strstr(password_buf, *requires);
if(str == NULL)
recv_data(sockfd, file);
else
{
scanf("%s", &password);
send_data(sockfd, password);
}
recv_data(sockfd, rebuf);
fwrite(rebuf, 1, sizeof(rebuf), re);
fclose(re);
restr = strstr(file_contents, "error_");
if(restr != NULL)
printf("%s\n", re);
}
int main(void)
{
struct sockaddr_in client, server_addr;
int sockfd, connected;
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(80);
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if(sockfd == -1)
printf("%s", "Error opening socket");
connected = connect(sockfd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));
if(connected == -1)
printf("%s", "Error binding socket");
send_file_cs(sockfd);
client_request_file_cs(sockfd);
shutdown(sockfd, SHUT_RDWR);
return 0;
}
提前感谢您的帮助。除了注释中的其他有效问题/要点外，代码中的内存分配可能会导致分段错误 char*file_位置和其他位置正在被使用，就好像已经分配了内存一样 您在scanf%s和&file\u位置中使用变量；在分配内存之前，调用未定义的行为，并且很可能对运行时错误至少部分负责 在scanf语句之前添加内存。下面是两个如何实现这一点的示例： 1使用[m][c]alloc创建堆内存：
char *file_location;
file_location = malloc(MAX_FILENAME_LEN);//or your systems value for max directory length
if(file_location)
{
scanf("%s", &file_location);
...
char file_name[256];
char *file_location = file_name;
file_location = file_name;
scanf("%s", &file_location);
注意：您不需要\EOF。当对等机断开连接时，recv将返回零，这是您没有检查的。您也没有检查它是否有错误。这是一个非常奇怪的代码EJP 19分钟前您是否使用调试器检查了此代码？我找不到您如何在客户端代码中设置server\u addr.sin\u addr.s\u addr。您似乎在未初始化地址的情况下调用connect，这很糟糕，但可能不是唯一的问题。似乎connect问题会导致错误连接拒绝。在这种情况下，最小、完整且可验证的示例必须是2个C文件和2个程序中的530行代码？在尝试这两个之后，无论我输入了什么地址，它仍然返回错误错误地址。@Winneric-我提供的内存创建问题/解决方案只是代码示例中需要在运行之前解决的几个潜在问题之一。您是否在任何地方初始化了服务器\u addr.sin\u addr.s\u addr？你有没有试过自己用调试器进行调试？我会的，除非我现在离我的编译器不近
char file_location[256];
scanf("%s", &file_location);