修正cgi，优化代码结构

2026-06-24 06:00:24 +08:00 · 2021-08-07 17:46:08 +08:00
parent 1b7e8a5119
commit fe8277a3bf
2 changed files with 324 additions and 349 deletions
--- a/README.md
+++ b/README.md
@@ -20,7 +20,6 @@ A necessary subset of `HTTP 1.0` with following options of request header being
 - 200 OK
 - 400 BAD REQUEST
 - 404 NOT FOUND
- 414 Request-URI Too Long
 - 500 Internal Server Error
 - 501 Method Not Implemented

--- a/server.c
+++ b/server.c
@@ -54,11 +54,10 @@ static void execute_cgi(int, int, const HTTP_REQUEST*);
 static uint32_t get_file_size(const char *, int);
 static int get_line(int, char *, int);
 static void handle_quit(int);
-static void headers(int, const char *);
+static int headers(int, const char *);
 static void not_found(int);
 static void serve_file(int, const char *);
 static int startup(u_int16_t *);
-static void toolong(int);
 static void unimplemented(int);

 /**********************************************************************/
@@ -70,60 +69,38 @@ static void unimplemented(int);
 /* read & discard headers */
 #define discard(client) \
 	while((numchars > 0) && strcmp("\n", buf)) numchars = get_line(client, buf, sizeof(buf))
+#define methodequ(str, method) (*(uint32_t*)(method) == *(uint32_t*)(str))
+#define skiptext(buf, j, cap) while(!ISspace(buf[j]) && (j < (cap))) j++
+#define skipspace(buf, j, cap) while(ISspace(buf[j]) && (j < (cap))) j++
+#define getmethod(method_type) ((method_type == GET)?"GET":"POST")

 static void accept_request(void *cli) {
-    pthread_detach(pthread_self());
 	int client = (int)cli;
-    char buf[1024];
-    int numchars;
-    char method[255];
-    char url[255];
-    char path[512];
-    size_t i, j;
+	char buf[1024], *path, *query_string;
+	int numchars, cgi = 0, j; // cgi becomes true if server decides this is a CGI program
 	struct stat st;
-    int cgi = 0; /* becomes true if server decides this is a CGI program */
-    char *query_string = NULL;
 	METHOD_TYPE method_type;

+	pthread_detach(pthread_self());
+
 	numchars = get_line(client, buf, sizeof(buf));
-    i = 0;
 	j = 0;
-    while(!ISspace(buf[j]) &&(i < sizeof(method) - 1)) {
-        method[i] = buf[j];
-        i++;
-        j++;
-    }
-    method[i] = '\0';
+	skiptext(buf, j, numchars - 1);
+	buf[j] = '\0';

-    if(strcasecmp(method, "GET") == 0) {
-        method_type = GET;
-    }
-
-    if(strcasecmp(method, "POST") == 0) {
-        if(method_type == GET) {
-			discard(client);
-            unimplemented(client);
-            return;
-        } else {
+	if(methodequ(buf, "GET")) method_type = GET;
+	else if(methodequ(buf, "POST")) {
 		cgi = 1;
 		method_type = POST;
 	}
-    }

-    i = 0;
-    while(ISspace(buf[j]) && (j < sizeof(buf))) j++;
-    for(; !ISspace(buf[j]) && (i < sizeof(url) - 1) && (j < sizeof(buf)); i++, j++) {
-        url[i] = buf[j];
-    }
-    if(!ISspace(buf[j])) {
-		discard(client);
-        toolong(client);
-        return;
-    }
-    url[i] = '\0';
+	skipspace(buf, j, numchars - 1);
+	path = buf + j + 1;
+	skiptext(buf, j, numchars - 1);
+	buf[j] = 0;

 	if(method_type == GET) {
-        query_string = url;
+		query_string = path;
 		while((*query_string != '?') && (*query_string != '\0')) query_string++;
 		if(*query_string == '?') {
 			cgi = 1;
@@ -132,17 +109,29 @@ static void accept_request(void *cli) {
 		}
 	}

-    char* url_start = url + 1;
 	// skip possible ../
-    while((*url_start == '.' || *url_start == '/' || *url_start == '#') && *url_start != 0) url_start++;
-    path[0] = '.'; path[1] = '/'; path[2] = 0;
-    if(*url_start) strncat(path, url_start, 499);
-    printf("%s %s with query '%s': ", method, path, query_string);
+	while((*path == '.' || *path == '/' || *path == '#') && *path != 0) path++;
+	path -= 2;
+	path[0] = '.'; path[1] = '/';
+
+	printf("[%s] <%s> (%s) = ", getmethod(method_type), path, query_string);
 	// 花括号不可省略
 	if(stat(path, &st) == -1) {
 		discard(client);
 		not_found(client);
 	} else {
+		int pathlen = strlen(path) + 1;
+		char* path_heap = malloc(pathlen + 11);	// 11 is for possible /index.html
+		memcpy(path_heap, path, pathlen);
+		printf("<%d> ", pathlen);
+		path = path_heap;
+
+		char* query_heap = query_string;
+		int query_length = strlen(query_heap) + 1;
+		query_string = malloc(query_length);
+		memcpy(query_string, query_heap, query_length);
+		printf("(%d) ", query_length);
+
 		if((st.st_mode & S_IFMT) == S_IFDIR) {
 			strcat(path, "/index.html");
 			// 花括号不可省略
@@ -154,7 +143,7 @@ static void accept_request(void *cli) {
 			}
 		}
 		int content_length = 0;
-        if((st.st_mode & S_IXUSR) ||(st.st_mode & S_IXGRP) ||(st.st_mode & S_IXOTH)) cgi = 1;
+		cgi &= ((st.st_mode & S_IXUSR) || (st.st_mode & S_IXGRP) || (st.st_mode & S_IXOTH));
 		while((numchars > 0) && strcmp("\n", buf)) {
 			numchars = get_line(client, buf, sizeof(buf));
 			if(!content_length && strcasestr(buf, "Content-Length: ")) {
@@ -166,11 +155,12 @@ static void accept_request(void *cli) {
 		else {
 			HTTP_REQUEST request;
 			request.path = path;
-            request.method = method;
+			request.method = getmethod(method_type);
 			request.method_type = method_type;
 			request.query_string = query_string;
 			execute_cgi(client, content_length, &request);
 		}
+		free(path); free(query_string);
 	}
 	close(client);
 }
@@ -182,6 +172,7 @@ static void accept_request(void *cli) {
 #define HTTP400 "HTTP/1.0 400 BAD REQUEST\r\nContent-Type: text/html\r\n\r\n<P>Your browser sent a bad request, such as a POST without a Content-Length.\r\n"
 static void bad_request(int client) {
 	send(client, HTTP400, sizeof(HTTP400)-1, 0);
+	puts("400 BAD REQUEST.");
 }

 /**********************************************************************/
@@ -201,7 +192,7 @@ static void cat(int client, FILE *resource) {
 		rewind(resource);
 		sendfile(client, fileno(resource), &len, file_size);
 	#endif
-    printf("Send %lu bytes.\n", len);
+	printf("Sendfile: %lu bytes.\n", len);
 }

 /**********************************************************************/
@@ -211,6 +202,7 @@ static void cat(int client, FILE *resource) {
 #define HTTP500 "HTTP/1.0 500 Internal Server Error\r\nContent-Type: text/html\r\n\r\n<P>Internal Server Error.\r\n"
 static void cannot_execute(int client) {
 	send(client, HTTP500, sizeof(HTTP500)-1, 0);
+	puts("500 Internal Server Error.");
 }

 /**********************************************************************/
@@ -230,10 +222,8 @@ static void error_die(const char *sc) {
 *             path to the CGI script */
 /**********************************************************************/
 static void execute_cgi(int client, int content_length, const HTTP_REQUEST* request) {
-    int cgi_output[2];
-    int cgi_input[2];
+	int cgi_output[2], cgi_input[2], i;
 	pid_t pid;
-    int i;

 	if(pipe(cgi_output) < 0 || pipe(cgi_input) < 0 || (pid = fork()) < 0) cannot_execute(client);
 	/* child: CGI script */
@@ -291,7 +281,7 @@ static void execute_cgi(int client, int content_length, const HTTP_REQUEST* requ
 			if(offset > 0) p += offset;
 			else cannot_execute(client);
 		}
-        printf("cgi msg cnt: %u bytes.\n", cnt);
+		printf("CGI msg len: %u bytes.\n", cnt);
 		if(cnt > 0) {
 			int len = 0;
 			#if __APPLE__
@@ -311,7 +301,7 @@ static void execute_cgi(int client, int content_length, const HTTP_REQUEST* requ
 					len += delta;
 				}
 			#endif
-            printf("cgi send %d bytes\n", len);
+			printf("CGI send %d bytes\n", len);
 		}
 		close(cgi_output[0]);
 		close(cgi_input[1]);
@@ -328,13 +318,10 @@ static uint32_t get_file_size(const char *filepath, int client) {
 	uint32_t sz;
 	if(!stat(filepath, &statbuf)) {
 		sz = statbuf.st_size;
-        printf("file size: %u\n", sz);
+		printf("[%u] - ", sz);
 		return sz;
 	}
-    else {
-        cannot_execute(client);
-        error_die("stat");
-    }
+	else return 0;
 }

 /**********************************************************************/
@@ -357,23 +344,19 @@ static int get_line(int sock, char *buf, int size) {

 	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);
+				if((n > 0) && (c == '\n')) recv(sock, &c, 1, 0);
 				else c = '\n';
 			}
-            buf[i] = c;
-            i++;
-        }
-        else c = '\n';
+			buf[i++] = c;
+		} else c = '\n';
 	}
 	buf[i] = '\0';

-    return(i);
+	return i;
 }

 /**********************************************************************/
@@ -400,16 +383,19 @@ static void handle_quit(int signo) {
 #define HTTP200 "HTTP/1.0 200 OK\r\n"
 #define CONTENT_TYPE "Content-Type: %s\r\n"
 #define CONTENT_LEN "Content-Length: %d\r\n"
-static void headers(int client, const char *filepath) {
+static int headers(int client, const char *filepath) {
 	char buf[1024];
 	uint32_t offset = 0;
 	uint32_t extpos = strlen(filepath) - 4;
-
+	uint32_t file_size = get_file_size(filepath, client);
+	if(file_size) {
 		ADD_HERDER(HTTP200 SERVER_STRING);
 		ADD_HERDER_PARAM(CONTENT_TYPE, EXTNM_IS_NOT("html")?(EXTNM_IS_NOT(".css")?(EXTNM_IS_NOT(".ico")?"text/plain":"image/x-icon"):"text/css"):"text/html");
-    ADD_HERDER_PARAM(CONTENT_LEN "\r\n", get_file_size(filepath, client));
+		ADD_HERDER_PARAM(CONTENT_LEN "\r\n", file_size);
 		send(client, buf, offset, 0);
 		puts("200 OK.");
+		return 1;
+	} else return 0;
 }

 /**********************************************************************/
@@ -432,12 +418,11 @@ static void serve_file(int client, const char *filename) {
 	FILE *resource = NULL;

 	resource = fopen(filename, "rb");
-    if(resource == NULL) not_found(client);
-    else {
-        headers(client, filename);
-        cat(client, resource);
-    }
+	if(resource) {
+		if(headers(client, filename)) cat(client, resource);
+		else not_found(client);
 		fclose(resource);
+	} else not_found(client);
 }

 /**********************************************************************/
@@ -486,16 +471,6 @@ static int startup(uint16_t *port) {
 	return(httpd);
 }

-/**********************************************************************/
-/* Inform the client that the requested web method has not been
- * implemented.
- * Parameter: the client socket */
-/**********************************************************************/
-#define HTTP414 "HTTP/1.0 414 Request-URI Too Long\r\n" SERVER_STRING "Content-Type: text/html\r\n\r\n<HTML><HEAD><TITLE>Request-URI Too Long\r\n</TITLE></HEAD>\r\n<BODY><P>HTTP request url length is over 254 chars.\r\n</BODY></HTML>\r\n"
-static void toolong(int client) {
-    send(client, HTTP414, sizeof(HTTP414)-1, 0);
-}
-
 /**********************************************************************/
 /* Inform the client that the requested web method has not been
 * implemented.
@@ -504,13 +479,14 @@ static void toolong(int client) {
 #define HTTP501 "HTTP/1.0 501 Method Not Implemented\r\n" SERVER_STRING "Content-Type: text/html\r\n\r\n<HTML><HEAD><TITLE>Method Not Implemented\r\n</TITLE></HEAD>\r\n<BODY><P>HTTP request method not supported.\r\n</BODY></HTML>\r\n"
 static void unimplemented(int client) {
 	send(client, HTTP501, sizeof(HTTP501)-1, 0);
+	puts("501 Method Not Implemented.");
 }

 /**********************************************************************/
 /* simple-http-server
- * Usage: simple-http-server -d port chdir
+ * Usage: simple-http-server [-d] [-p <port>] [-r <rootdir>] [-u <uid>]
 /**********************************************************************/
-#define ACCEPT_CLI() {\
+#define accept_client(client_sock, server_sock, client_name, client_name_len, newthread) {\
 	while(1) {\
 		client_sock = accept(server_sock,(struct sockaddr *)&client_name, &client_name_len);\
 		if(client_sock == -1) break;\
@@ -561,7 +537,7 @@ int main(int argc, char **argv) {
 				pid = fork();
 			}
 			if(pid < 0) perror("fork");
-            else ACCEPT_CLI();
-        } else ACCEPT_CLI();
+			else accept_client(client_sock, server_sock, client_name, client_name_len, newthread);
+		} else accept_client(client_sock, server_sock, client_name, client_name_len, newthread);
 	}
 }