http服务
一个简单的http服务
/* J. David's webserver */
/* This is a simple webserver.
* Created November 1999 by J. David Blackstone.
* CSE 4344 (Network concepts), Prof. Zeigler
* University of Texas at Arlington
*/
/* This program compiles for Sparc Solaris 2.6.
* To compile for Linux:
* 1) Comment out the #include line.
* 2) Comment out the line that defines the variable newthread.
* 3) Comment out the two lines that run pthread_create().
* 4) Uncomment the line that runs accept_request().
* 5) Remove -lsocket from the Makefile.
*/
#include Your browser sent a bad request, "
);
send(client, buf, sizeof (buf), 0);
sprintf(buf, "such as a POST without a Content-Length.\r\n");
send(client, buf, sizeof (buf), 0);
}
/* Put the entire contents of a file out on a socket. This function
* is named after the UNIX "cat" command, because it might have been
* easier just to do something like pipe, fork, and exec("cat").
* Parameters: the client socket descriptor
* FILE pointer for the file to cat */
void cat(int client, FILE *resource) {
//返回文件数据
char buf[1024];
fgets(buf, sizeof (buf), resource);
while (!feof(resource)) {
//循环发送文件
send(client, buf, strlen(buf), 0);
fgets(buf, sizeof (buf), resource);
}
}
/* Inform the client that a CGI script could not be executed.
* Parameter: the client socket descriptor. */
void cannot_execute(int client) {
//返回500 服务器内部错误
char buf[1024];
sprintf(buf, "HTTP/1.0 500 Internal Server Error\r\n");
send(client, buf, strlen(buf), 0);
sprintf(buf, "Content-type: text/html\r\n");
send(client, buf, strlen(buf), 0);
sprintf(buf, "\r\n");
send(client, buf, strlen(buf), 0);
sprintf(buf, "Error prohibited CGI execution.\r\n"
);
send(client, buf, strlen(buf), 0);
}
/* Print out an error message with perror() (for system errors; based
* on value of errno, which indicates system call errors) and exit the
* program indicating an error. */
void error_die(const char *sc) {
perror(sc);
exit(1);
}
/* Execute a CGI script. Will need to set environment variables as
* appropriate. CGI (Common Gateway Interface) 通用网关接口,参数查询
* Parameters: client socket descriptor
* path to the CGI script */
void execute_cgi(int client, const char *path,
const char *method, const char *query_string) {
char buf[1024];
int cgi_output[2];
int cgi_input[2];
pid_t pid;
int status;
int i;
char c;
int numchars = 1;
int content_length = -1;
buf[0] = 'A';
buf[1] = '\0';
if (strcasecmp(method, "GET") == 0)
while ((numchars > 0) && strcmp("\n", buf)) /* read & discard headers */
numchars = get_line(client, buf, sizeof (buf));
else /* POST */ {
numchars = get_line(client, buf, sizeof (buf));
while ((numchars > 0) && strcmp("\n", buf)) {
buf[15] = '\0';
if (strcasecmp(buf, "Content-Length:") == 0)
content_length = atoi(&(buf[16]));
numchars = get_line(client, buf, sizeof (buf));
}
if (content_length == -1) {
bad_request(client);
return;
}
}
sprintf(buf, "HTTP/1.0 200 OK\r\n");
send(client, buf, strlen(buf), 0);
//创建管道
if (pipe(cgi_output) < 0) {
//返回500 服务器内部错误
cannot_execute(client);
return;
}
if (pipe(cgi_input) < 0) {
cannot_execute(client);
return;
}
if ((pid = fork()) < 0) {
cannot_execute(client);
return;
}
if (pid == 0) /* child: CGI script */ {
//再子进程中处理哦
char meth_env[255];
char query_env[255];
char length_env[255];
//操作管道的读写端
dup2(cgi_output[1], 1);
dup2(cgi_input[0], 0);
close(cgi_output[0]);
close(cgi_input[1]);
sprintf(meth_env, "REQUEST_METHOD=%s", method);
//放入环境变量
putenv(meth_env);
if (strcasecmp(method, "GET") == 0) {
sprintf(query_env, "QUERY_STRING=%s", query_string);
putenv(query_env);
} else { /* POST */
sprintf(length_env, "CONTENT_LENGTH=%d", content_length);
putenv(length_env);
}
//执行path
execl(path, path, NULL);
exit(0);
} else { /* parent */
close(cgi_output[1]);
close(cgi_input[0]);
if (strcasecmp(method, "POST") == 0)
for (i = 0; i < content_length; i++) {
recv(client, &c, 1, 0);
write(cgi_input[1], &c, 1);
}
while (read(cgi_output[0], &c, 1) > 0)
send(client, &c, 1, 0);
close(cgi_output[0]);
close(cgi_input[1]);
waitpid(pid, &status, 0);
}
}
/* Get a line from a socket, whether the line ends in a newline,
* carriage return, or a CRLF combination. Terminates the string read
* with a null character. If no newline indicator is found before the
* end of the buffer, the string is terminated with a null. If any of
* the above three line terminators is read, the last character of the
* string will be a linefeed and the string will be terminated with a
* null character.
* Parameters: the socket descriptor
* the buffer to save the data in
* the size of the buffer
* Returns: the number of bytes stored (excluding null) */
int get_line(int sock, char *buf, int size) {
int i = 0;
char c = '\0';
int n;
while ((i < size - 1) && (c != '\n')) {
n = recv(sock, &c, 1, 0);
/* DEBUG printf("%02X\n", c); */
if (n > 0) {
if (c == '\r') {
n = recv(sock, &c, 1, MSG_PEEK);
/* DEBUG printf("%02X\n", c); */
if ((n > 0) && (c == '\n'))
recv(sock, &c, 1, 0);
else
c = '\n';
}
buf[i] = c;
i++;
} else
c = '\n';
}
buf[i] = '\0';
return (i);
}
/** Return the informational HTTP headers about a file. */
/* Parameters: the socket to print the headers on
* the name of the file */
void headers(int client, const char *filename) {
//先返回文件头部信息
char buf[1024];
(void) filename; /* could use filename to determine file type */
strcpy(buf, "HTTP/1.0 200 OK\r\n");
send(client, buf, strlen(buf), 0);
strcpy(buf, SERVER_STRING);
send(client, buf, strlen(buf), 0);
sprintf(buf, "Content-Type: text/html\r\n");
send(client, buf, strlen(buf), 0);
strcpy(buf, "\r\n");
send(client, buf, strlen(buf), 0);
}
/* Give a client a 404 not found status message. */
void not_found(int client) {
//返回http 404协议
char buf[1024];
//先发送http协议头
sprintf(buf, "HTTP/1.0 404 NOT FOUND\r\n");
send(client, buf, strlen(buf), 0);
//再发送serverName
sprintf(buf, SERVER_STRING);
send(client, buf, strlen(buf), 0);
//再发送Content-Type
sprintf(buf, "Content-Type: text/html\r\n");
send(client, buf, strlen(buf), 0);
//发送换行符
sprintf(buf, "\r\n");
send(client, buf, strlen(buf), 0);
//发送html主体内容
sprintf(buf, "Not Found \r\n");
send(client, buf, strlen(buf), 0);
sprintf(buf, "The server could not fulfill\r\n"
);
send(client, buf, strlen(buf), 0);
sprintf(buf, "your request because the resource specified\r\n");
send(client, buf, strlen(buf), 0);
sprintf(buf, "is unavailable or nonexistent.\r\n");
send(client, buf, strlen(buf), 0);
sprintf(buf, "\r\n");
send(client, buf, strlen(buf), 0);
}
/* Send a regular file to the client. Use headers, and report
* errors to client if they occur.
* Parameters: a pointer to a file structure produced from the socket
* file descriptor
* the name of the file to serve */
void serve_file(int client, const char *filename) {
//返回文件数据
FILE *resource = NULL;
int numchars = 1;
char buf[1024];
buf[0] = 'A';
buf[1] = '\0';
while ((numchars > 0) && strcmp("\n", buf)) /* read & discard headers */
numchars = get_line(client, buf, sizeof (buf));
resource = fopen(filename, "r");
if (resource == NULL)
not_found(client);
else {
//先返回头部信息
headers(client, filename);
cat(client, resource);
}
fclose(resource);
}
/** This function starts the process of listening for web connections
* on a specified port. If the port is 0, then dynamically allocate a
* port and modify the original port variable to reflect the actual
* port.
* Parameters: pointer to variable containing the port to connect on
* Returns: the socket */
int startup(u_short *port) {
int httpd = 0;
struct sockaddr_in name;
httpd = socket(PF_INET, SOCK_STREAM, 0);
if (httpd == -1)
error_die("socket");
memset(&name, 0, sizeof (name));
name.sin_family = AF_INET;
name.sin_port = htons(*port);
name.sin_addr.s_addr = htonl(INADDR_ANY);
if (bind(httpd, (struct sockaddr *) &name, sizeof (name)) < 0)
error_die("bind");
if (*port == 0) /* if dynamically allocating a port */ {
int namelen = sizeof (name);
if (getsockname(httpd, (struct sockaddr *) &name, &namelen) == -1)
error_die("getsockname");
*port = ntohs(name.sin_port);
}
if (listen(httpd, 5) < 0)
error_die("listen");
return (httpd);
}
/** Inform the client that the requested web method has not been
* implemented.
* Parameter: the client socket */
void unimplemented(int client) {
//方法未实现
char buf[1024];
sprintf(buf, "HTTP/1.0 501 Method Not Implemented\r\n");
send(client, buf, strlen(buf), 0);
sprintf(buf, SERVER_STRING);
send(client, buf, strlen(buf), 0);
sprintf(buf, "Content-Type: text/html\r\n");
send(client, buf, strlen(buf), 0);
sprintf(buf, "\r\n");
send(client, buf, strlen(buf), 0);
sprintf(buf, "Method Not Implemented\r\n"</span>);
send(client, buf, <span class="hljs-built_in">strlen</span>(buf), <span class="hljs-number">0</span>);
<span class="hljs-built_in">sprintf</span>(buf, <span class="hljs-string">" \r\n");
send(client, buf, strlen(buf), 0);
sprintf(buf, "HTTP request method not supported.\r\n"
);
send(client, buf, strlen(buf), 0);
sprintf(buf, "\r\n");
send(client, buf, strlen(buf), 0);
}
void PrintSocketAddress(const struct sockaddr *address, FILE *stream) {
// Test for address and stream
if (address == NULL || stream == NULL)
return;
void *numericAddress; // Pointer to binary address
// Buffer to contain result (IPv6 sufficient to hold IPv4)
char addrBuffer[INET6_ADDRSTRLEN];
in_port_t port; // Port to print
// Set pointer to address based on address family
switch (address->sa_family) {
case AF_INET:
numericAddress = &((struct sockaddr_in *) address)->sin_addr;
port = ntohs(((struct sockaddr_in *) address)->sin_port);
break;
case AF_INET6:
numericAddress = &((struct sockaddr_in6 *) address)->sin6_addr;
port = ntohs(((struct sockaddr_in6 *) address)->sin6_port);
break;
default:
fputs("[unknown type]", stream); // Unhandled type
return;
}
// Convert binary to printable address
if (inet_ntop(address->sa_family, numericAddress, addrBuffer,
sizeof (addrBuffer)) == NULL)
fputs("[invalid address]", stream); // Unable to convert
else {
fprintf(stream, "来自%s", addrBuffer);
if (port != 0) // Zero not valid in any socket addr
fprintf(stream, "-%u\n", port);
}
}
//主函数入口,编译时
//gcc -W -Wall -lsocket -lpthread -o httpd httpd.c 在linux 可以去掉-lsocket
//参考开源tinyhttpd
int main(int argc, char *argv[]) {
int server_sock = -1;
if (argv[1] == NULL)
argv[1] = "80";
u_short port = atoi(argv[1]);
int client_sock = -1;
struct sockaddr_in client_name;
int client_name_len = sizeof (client_name);
pthread_t newthread;
//建立socket，监听端口
server_sock = startup(&port);
printf("httpd running on port %d\n", port);
//获取程序目录
char dirPath[128];
getcwd(dirPath, 128);
printf("current program Path: %s\n",dirPath);
while (1) {
client_sock = accept(server_sock,
(struct sockaddr *) &client_name,
&client_name_len);
if (client_sock == -1)
error_die("accept");
PrintSocketAddress((struct sockaddr*) &client_name, stdout);
/* accept_request(client_sock); */
//printf("client_sock:%d\n",client_sock);
//子线程处理http 请求
if (pthread_create(&newthread, NULL, accept_request, (void*) client_sock) != 0)
perror("pthread_create");
}
close(server_sock);
return (0);
}
编译：
gcc httpserver.c -o httpserver -lpthread