《CSAPP》（第3版）答案（第十一章）
《CSAPP》（第3版）答案（第十一章）
P6
- A
#include "csapp.h"
void doit(int fd);
void read_requesthdrs(rio_t *rp);
int parse_uri(char *uri, char *filename, char *cgiargs);
void serve_static(int fd, char *filename, int filesize);
void get_filetype(char *filename, char *filetype);
void serve_dynamic(int fd, char *filename, char *cgiargs);
void clienterror(int fd, char *cause, char *errnum,
char *shortmsg, char *longmsg);
void echo(int connfd);
int main(int argc, char **argv)
{
int listenfd, connfd;
char hostname[MAXLINE], port[MAXLINE];
socklen_t clientlen;
struct sockaddr_storage clientaddr;
/* Check command line args */
if (argc != 2) {
fprintf(stderr, "usage: %s \n" , argv[0]);
exit(1);
}
listenfd = Open_listenfd(argv[1]);
while (1) {
clientlen = sizeof(clientaddr);
connfd = Accept(listenfd, (SA *)&clientaddr, &clientlen); //line:netp:tiny:accept
Getnameinfo((SA *) &clientaddr, clientlen, hostname, MAXLINE,
port, MAXLINE, 0);
printf("Accepted connection from (%s, %s)\n", hostname, port);
echo(connfd);
Close(connfd); //line:netp:tiny:close
}
}
void echo(int connfd) {
size_t n;
char buf[MAXLINE];
rio_t rio;
Rio_readinitb(&rio, connfd);
while ((n = Rio_readlineb(&rio, buf, MAXLINE)) != 0) {
if (strcmp(buf, "\r\n") == 0)
break;
Rio_writen(connfd, buf, n);
}
}
/*
* doit - handle one HTTP request/response transaction
*/
void doit(int fd)
{
int is_static;
struct stat sbuf;
char buf[MAXLINE], method[MAXLINE], uri[MAXLINE], version[MAXLINE];
char filename[MAXLINE], cgiargs[MAXLINE];
rio_t rio;
/* Read request line and headers */
Rio_readinitb(&rio, fd);
if (!Rio_readlineb(&rio, buf, MAXLINE)) //line:netp:doit:readrequest
return;
printf("%s", buf);
sscanf(buf, "%s %s %s", method, uri, version); //line:netp:doit:parserequest
if (strcasecmp(method, "GET")) { //line:netp:doit:beginrequesterr
clienterror(fd, method, "501", "Not Implemented",
"Tiny does not implement this method");
return;
} //line:netp:doit:endrequesterr
read_requesthdrs(&rio); //line:netp:doit:readrequesthdrs
/* Parse URI from GET request */
is_static = parse_uri(uri, filename, cgiargs); //line:netp:doit:staticcheck
if (stat(filename, &sbuf) < 0) { //line:netp:doit:beginnotfound
clienterror(fd, filename, "404", "Not found",
"Tiny couldn't find this file");
return;
} //line:netp:doit:endnotfound
if (is_static) { /* Serve static content */
if (!(S_ISREG(sbuf.st_mode)) || !(S_IRUSR & sbuf.st_mode)) { //line:netp:doit:readable
clienterror(fd, filename, "403", "Forbidden",
"Tiny couldn't read the file");
return;
}
serve_static(fd, filename, sbuf.st_size); //line:netp:doit:servestatic
}
else { /* Serve dynamic content */
if (!(S_ISREG(sbuf.st_mode)) || !(S_IXUSR & sbuf.st_mode)) { //line:netp:doit:executable
clienterror(fd, filename, "403", "Forbidden",
"Tiny couldn't run the CGI program");
return;
}
serve_dynamic(fd, filename, cgiargs); //line:netp:doit:servedynamic
}
}
/*
* read_requesthdrs - read HTTP request headers
*/
void read_requesthdrs(rio_t *rp)
{
char buf[MAXLINE];
Rio_readlineb(rp, buf, MAXLINE);
printf("%s", buf);
while(strcmp(buf, "\r\n")) { //line:netp:readhdrs:checkterm
Rio_readlineb(rp, buf, MAXLINE);
printf("%s", buf);
}
return;
}
/*
* parse_uri - parse URI into filename and CGI args
* return 0 if dynamic content, 1 if static
*/
int parse_uri(char *uri, char *filename, char *cgiargs)
{
char *ptr;
if (!strstr(uri, "cgi-bin")) { /* Static content */ //line:netp:parseuri:isstatic
strcpy(cgiargs, ""); //line:netp:parseuri:clearcgi
strcpy(filename, "."); //line:netp:parseuri:beginconvert1
strcat(filename, uri); //line:netp:parseuri:endconvert1
if (uri[strlen(uri)-1] == '/') //line:netp:parseuri:slashcheck
strcat(filename, "home.html"); //line:netp:parseuri:appenddefault
return 1;
}
else { /* Dynamic content */ //line:netp:parseuri:isdynamic
ptr = index(uri, '?'); //line:netp:parseuri:beginextract
if (ptr) {
strcpy(cgiargs, ptr+1);
*ptr = '\0';
}
else
strcpy(cgiargs, ""); //line:netp:parseuri:endextract
strcpy(filename, "."); //line:netp:parseuri:beginconvert2
strcat(filename, uri); //line:netp:parseuri:endconvert2
return 0;
}
}
/*
* serve_static - copy a file back to the client
*/
void serve_static(int fd, char *filename, int filesize)
{
int srcfd;
char *srcp, filetype[MAXLINE], buf[MAXBUF];
/* Send response headers to client */
get_filetype(filename, filetype); //line:netp:servestatic:getfiletype
sprintf(buf, "HTTP/1.0 200 OK\r\n"); //line:netp:servestatic:beginserve
sprintf(buf, "%sServer: Tiny Web Server\r\n", buf);
sprintf(buf, "%sConnection: close\r\n", buf);
sprintf(buf, "%sContent-length: %d\r\n", buf, filesize);
sprintf(buf, "%sContent-type: %s\r\n\r\n", buf, filetype);
Rio_writen(fd, buf, strlen(buf)); //line:netp:servestatic:endserve
printf("Response headers:\n");
printf("%s", buf);
/* Send response body to client */
srcfd = Open(filename, O_RDONLY, 0); //line:netp:servestatic:open
srcp = Mmap(0, filesize, PROT_READ, MAP_PRIVATE, srcfd, 0);//line:netp:servestatic:mmap
Close(srcfd); //line:netp:servestatic:close
Rio_writen(fd, srcp, filesize); //line:netp:servestatic:write
Munmap(srcp, filesize); //line:netp:servestatic:munmap
}
/*
* get_filetype - derive file type from file name
*/
void get_filetype(char *filename, char *filetype)
{
if (strstr(filename, ".html"))
strcpy(filetype, "text/html");
else if (strstr(filename, ".gif"))
strcpy(filetype, "image/gif");
else if (strstr(filename, ".png"))
strcpy(filetype, "image/png");
else if (strstr(filename, ".jpg"))
strcpy(filetype, "image/jpeg");
else
strcpy(filetype, "text/plain");
}
/*
* serve_dynamic - run a CGI program on behalf of the client
*/
void serve_dynamic(int fd, char *filename, char *cgiargs)
{
char buf[MAXLINE], *emptylist[] = { NULL };
/* Return first part of HTTP response */
sprintf(buf, "HTTP/1.0 200 OK\r\n");
Rio_writen(fd, buf, strlen(buf));
sprintf(buf, "Server: Tiny Web Server\r\n");
Rio_writen(fd, buf, strlen(buf));
if (Fork() == 0) { /* Child */ //line:netp:servedynamic:fork
/* Real server would set all CGI vars here */
setenv("QUERY_STRING", cgiargs, 1); //line:netp:servedynamic:setenv
Dup2(fd, STDOUT_FILENO); /* Redirect stdout to client */ //line:netp:servedynamic:dup2
Execve(filename, emptylist, environ); /* Run CGI program */ //line:netp:servedynamic:execve
}
Wait(NULL); /* Parent waits for and reaps child */ //line:netp:servedynamic:wait
}
/*
* clienterror - returns an error message to the client
*/
void clienterror(int fd, char *cause, char *errnum,
char *shortmsg, char *longmsg)
{
char buf[MAXLINE], body[MAXBUF];
/* Build the HTTP response body */
sprintf(body, "Tiny Error ");
sprintf(body, "%s"ffffff"">\r\n", body);
sprintf(body, "%s%s: %s\r\n", body, errnum, shortmsg);
sprintf(body, "%s%s: %s\r\n"
, body, longmsg, cause);
sprintf(body, "%s
The Tiny Web server\r\n", body);
/* Print the HTTP response */
sprintf(buf, "HTTP/1.0 %s %s\r\n", errnum, shortmsg);
Rio_writen(fd, buf, strlen(buf));
sprintf(buf, "Content-type: text/html\r\n");
Rio_writen(fd, buf, strlen(buf));
sprintf(buf, "Content-length: %d\r\n\r\n", (int)strlen(body));
Rio_writen(fd, buf, strlen(buf));
Rio_writen(fd, body, strlen(body));
}- B
GET / HTTP/1.1
Host: localhost:5000
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:53.0) Gecko/20100101 Firefox/53.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
- C
HTTP 1.1 - D
rfc
P7
#include "csapp.h"
void doit(int fd);
void read_requesthdrs(rio_t *rp);
int parse_uri(char *uri, char *filename, char *cgiargs);
void serve_static(int fd, char *filename, int filesize);
void get_filetype(char *filename, char *filetype);
void serve_dynamic(int fd, char *filename, char *cgiargs);
void clienterror(int fd, char *cause, char *errnum,
char *shortmsg, char *longmsg);
int main(int argc, char **argv)
{
int listenfd, connfd;
char hostname[MAXLINE], port[MAXLINE];
socklen_t clientlen;
struct sockaddr_storage clientaddr;
/* Check command line args */
if (argc != 2) {
fprintf(stderr, "usage: %s \n" , argv[0]);
exit(1);
}
listenfd = Open_listenfd(argv[1]);
while (1) {
clientlen = sizeof(clientaddr);
connfd = Accept(listenfd, (SA *)&clientaddr, &clientlen); //line:netp:tiny:accept
Getnameinfo((SA *) &clientaddr, clientlen, hostname, MAXLINE,
port, MAXLINE, 0);
printf("Accepted connection from (%s, %s)\n", hostname, port);
doit(connfd); //line:netp:tiny:doit
Close(connfd); //line:netp:tiny:close
}
}
/*
* doit - handle one HTTP request/response transaction
*/
void doit(int fd)
{
int is_static;
struct stat sbuf;
char buf[MAXLINE], method[MAXLINE], uri[MAXLINE], version[MAXLINE];
char filename[MAXLINE], cgiargs[MAXLINE];
rio_t rio;
/* Read request line and headers */
Rio_readinitb(&rio, fd);
if (!Rio_readlineb(&rio, buf, MAXLINE)) //line:netp:doit:readrequest
return;
printf("%s", buf);
sscanf(buf, "%s %s %s", method, uri, version); //line:netp:doit:parserequest
if (strcasecmp(method, "GET")) { //line:netp:doit:beginrequesterr
clienterror(fd, method, "501", "Not Implemented",
"Tiny does not implement this method");
return;
} //line:netp:doit:endrequesterr
read_requesthdrs(&rio); //line:netp:doit:readrequesthdrs
/* Parse URI from GET request */
is_static = parse_uri(uri, filename, cgiargs); //line:netp:doit:staticcheck
if (stat(filename, &sbuf) < 0) { //line:netp:doit:beginnotfound
clienterror(fd, filename, "404", "Not found",
"Tiny couldn't find this file");
return;
} //line:netp:doit:endnotfound
if (is_static) { /* Serve static content */
if (!(S_ISREG(sbuf.st_mode)) || !(S_IRUSR & sbuf.st_mode)) { //line:netp:doit:readable
clienterror(fd, filename, "403", "Forbidden",
"Tiny couldn't read the file");
return;
}
serve_static(fd, filename, sbuf.st_size); //line:netp:doit:servestatic
}
else { /* Serve dynamic content */
if (!(S_ISREG(sbuf.st_mode)) || !(S_IXUSR & sbuf.st_mode)) { //line:netp:doit:executable
clienterror(fd, filename, "403", "Forbidden",
"Tiny couldn't run the CGI program");
return;
}
serve_dynamic(fd, filename, cgiargs); //line:netp:doit:servedynamic
}
}
/*
* read_requesthdrs - read HTTP request headers
*/
void read_requesthdrs(rio_t *rp)
{
char buf[MAXLINE];
Rio_readlineb(rp, buf, MAXLINE);
printf("%s", buf);
while(strcmp(buf, "\r\n")) { //line:netp:readhdrs:checkterm
Rio_readlineb(rp, buf, MAXLINE);
printf("%s", buf);
}
return;
}
/*
* parse_uri - parse URI into filename and CGI args
* return 0 if dynamic content, 1 if static
*/
int parse_uri(char *uri, char *filename, char *cgiargs)
{
char *ptr;
if (!strstr(uri, "cgi-bin")) { /* Static content */ //line:netp:parseuri:isstatic
strcpy(cgiargs, ""); //line:netp:parseuri:clearcgi
strcpy(filename, "."); //line:netp:parseuri:beginconvert1
strcat(filename, uri); //line:netp:parseuri:endconvert1
if (uri[strlen(uri)-1] == '/') //line:netp:parseuri:slashcheck
strcat(filename, "home.html"); //line:netp:parseuri:appenddefault
return 1;
}
else { /* Dynamic content */ //line:netp:parseuri:isdynamic
ptr = index(uri, '?'); //line:netp:parseuri:beginextract
if (ptr) {
strcpy(cgiargs, ptr+1);
*ptr = '\0';
}
else
strcpy(cgiargs, ""); //line:netp:parseuri:endextract
strcpy(filename, "."); //line:netp:parseuri:beginconvert2
strcat(filename, uri); //line:netp:parseuri:endconvert2
return 0;
}
}
/*
* serve_static - copy a file back to the client
*/
void serve_static(int fd, char *filename, int filesize)
{
int srcfd;
char *srcp, filetype[MAXLINE], buf[MAXBUF];
/* Send response headers to client */
get_filetype(filename, filetype); //line:netp:servestatic:getfiletype
sprintf(buf, "HTTP/1.0 200 OK\r\n"); //line:netp:servestatic:beginserve
sprintf(buf, "%sServer: Tiny Web Server\r\n", buf);
sprintf(buf, "%sConnection: close\r\n", buf);
sprintf(buf, "%sContent-length: %d\r\n", buf, filesize);
sprintf(buf, "%sContent-type: %s\r\n\r\n", buf, filetype);
Rio_writen(fd, buf, strlen(buf)); //line:netp:servestatic:endserve
printf("Response headers:\n");
printf("%s", buf);
/* Send response body to client */
srcfd = Open(filename, O_RDONLY, 0); //line:netp:servestatic:open
srcp = Mmap(0, filesize, PROT_READ, MAP_PRIVATE, srcfd, 0);//line:netp:servestatic:mmap
Close(srcfd); //line:netp:servestatic:close
Rio_writen(fd, srcp, filesize); //line:netp:servestatic:write
Munmap(srcp, filesize); //line:netp:servestatic:munmap
}
/*
* get_filetype - derive file type from file name
*/
void get_filetype(char *filename, char *filetype)
{
if (strstr(filename, ".html"))
strcpy(filetype, "text/html");
else if (strstr(filename, ".gif"))
strcpy(filetype, "image/gif");
else if (strstr(filename, ".png"))
strcpy(filetype, "image/png");
else if (strstr(filename, ".jpg"))
strcpy(filetype, "image/jpeg");
else if (strstr(filename, ".mpeg"))
strcpy(filetype, "video/mpeg");
else
strcpy(filetype, "text/plain");
}
/*
* serve_dynamic - run a CGI program on behalf of the client
*/
void serve_dynamic(int fd, char *filename, char *cgiargs)
{
char buf[MAXLINE], *emptylist[] = { NULL };
/* Return first part of HTTP response */
sprintf(buf, "HTTP/1.0 200 OK\r\n");
Rio_writen(fd, buf, strlen(buf));
sprintf(buf, "Server: Tiny Web Server\r\n");
Rio_writen(fd, buf, strlen(buf));
if (Fork() == 0) { /* Child */ //line:netp:servedynamic:fork
/* Real server would set all CGI vars here */
setenv("QUERY_STRING", cgiargs, 1); //line:netp:servedynamic:setenv
Dup2(fd, STDOUT_FILENO); /* Redirect stdout to client */ //line:netp:servedynamic:dup2
Execve(filename, emptylist, environ); /* Run CGI program */ //line:netp:servedynamic:execve
}
Wait(NULL); /* Parent waits for and reaps child */ //line:netp:servedynamic:wait
}
/*
* clienterror - returns an error message to the client
*/
void clienterror(int fd, char *cause, char *errnum,
char *shortmsg, char *longmsg)
{
char buf[MAXLINE], body[MAXBUF];
/* Build the HTTP response body */
sprintf(body, "Tiny Error ");
sprintf(body, "%s"ffffff"">\r\n", body);
sprintf(body, "%s%s: %s\r\n", body, errnum, shortmsg);
sprintf(body, "%s%s: %s\r\n"
, body, longmsg, cause);
sprintf(body, "%s
The Tiny Web server\r\n", body);
/* Print the HTTP response */
sprintf(buf, "HTTP/1.0 %s %s\r\n", errnum, shortmsg);
Rio_writen(fd, buf, strlen(buf));
sprintf(buf, "Content-type: text/html\r\n");
Rio_writen(fd, buf, strlen(buf));
sprintf(buf, "Content-length: %d\r\n\r\n", (int)strlen(body));
Rio_writen(fd, buf, strlen(buf));
Rio_writen(fd, body, strlen(body));
}以上是源代码。如果不知道怎么跑关注私信我，我把整个工程文件夹发过去。
P8
#include "csapp.h"
void doit(int fd);
void read_requesthdrs(rio_t *rp);
int parse_uri(char *uri, char *filename, char *cgiargs);
void serve_static(int fd, char *filename, int filesize);
void get_filetype(char *filename, char *filetype);
void serve_dynamic(int fd, char *filename, char *cgiargs);
void clienterror(int fd, char *cause, char *errnum,
char *shortmsg, char *longmsg);
void sigchild_handler(int sig);
int main(int argc, char **argv)
{
int listenfd, connfd;
char hostname[MAXLINE], port[MAXLINE];
socklen_t clientlen;
struct sockaddr_storage clientaddr;
/* Check command line args */
if (argc != 2) {
fprintf(stderr, "usage: %s \n" , argv[0]);
exit(1);
}
if (Signal(SIGCHLD, sigchild_handler) == SIG_ERR)
unix_error("signal child handler error");
listenfd = Open_listenfd(argv[1]);
while (1) {
clientlen = sizeof(clientaddr);
connfd = Accept(listenfd, (SA *)&clientaddr, &clientlen); //line:netp:tiny:accept
Getnameinfo((SA *) &clientaddr, clientlen, hostname, MAXLINE,
port, MAXLINE, 0);
printf("Accepted connection from (%s, %s)\n", hostname, port);
doit(connfd); //line:netp:tiny:doit
Close(connfd); //line:netp:tiny:close
}
}
void sigchild_handler(int sig) {
int old_errno = errno;
int status;
pid_t pid;
while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
}
errno = old_errno;
}
/*
* doit - handle one HTTP request/response transaction
*/
void doit(int fd)
{
int is_static;
struct stat sbuf;
char buf[MAXLINE], method[MAXLINE], uri[MAXLINE], version[MAXLINE];
char filename[MAXLINE], cgiargs[MAXLINE];
rio_t rio;
/* Read request line and headers */
Rio_readinitb(&rio, fd);
if (!Rio_readlineb(&rio, buf, MAXLINE)) //line:netp:doit:readrequest
return;
printf("%s", buf);
sscanf(buf, "%s %s %s", method, uri, version); //line:netp:doit:parserequest
if (strcasecmp(method, "GET")) { //line:netp:doit:beginrequesterr
clienterror(fd, method, "501", "Not Implemented",
"Tiny does not implement this method");
return;
} //line:netp:doit:endrequesterr
read_requesthdrs(&rio); //line:netp:doit:readrequesthdrs
/* Parse URI from GET request */
is_static = parse_uri(uri, filename, cgiargs); //line:netp:doit:staticcheck
if (stat(filename, &sbuf) < 0) { //line:netp:doit:beginnotfound
clienterror(fd, filename, "404", "Not found",
"Tiny couldn't find this file");
return;
} //line:netp:doit:endnotfound
if (is_static) { /* Serve static content */
if (!(S_ISREG(sbuf.st_mode)) || !(S_IRUSR & sbuf.st_mode)) { //line:netp:doit:readable
clienterror(fd, filename, "403", "Forbidden",
"Tiny couldn't read the file");
return;
}
serve_static(fd, filename, sbuf.st_size); //line:netp:doit:servestatic
}
else { /* Serve dynamic content */
if (!(S_ISREG(sbuf.st_mode)) || !(S_IXUSR & sbuf.st_mode)) { //line:netp:doit:executable
clienterror(fd, filename, "403", "Forbidden",
"Tiny couldn't run the CGI program");
return;
}
serve_dynamic(fd, filename, cgiargs); //line:netp:doit:servedynamic
}
}
/*
* read_requesthdrs - read HTTP request headers
*/
void read_requesthdrs(rio_t *rp)
{
char buf[MAXLINE];
Rio_readlineb(rp, buf, MAXLINE);
printf("%s", buf);
while(strcmp(buf, "\r\n")) { //line:netp:readhdrs:checkterm
Rio_readlineb(rp, buf, MAXLINE);
printf("%s", buf);
}
return;
}
/*
* parse_uri - parse URI into filename and CGI args
* return 0 if dynamic content, 1 if static
*/
int parse_uri(char *uri, char *filename, char *cgiargs)
{
char *ptr;
if (!strstr(uri, "cgi-bin")) { /* Static content */ //line:netp:parseuri:isstatic
strcpy(cgiargs, ""); //line:netp:parseuri:clearcgi
strcpy(filename, "."); //line:netp:parseuri:beginconvert1
strcat(filename, uri); //line:netp:parseuri:endconvert1
if (uri[strlen(uri)-1] == '/') //line:netp:parseuri:slashcheck
strcat(filename, "home.html"); //line:netp:parseuri:appenddefault
return 1;
}
else { /* Dynamic content */ //line:netp:parseuri:isdynamic
ptr = index(uri, '?'); //line:netp:parseuri:beginextract
if (ptr) {
strcpy(cgiargs, ptr+1);
*ptr = '\0';
}
else
strcpy(cgiargs, ""); //line:netp:parseuri:endextract
strcpy(filename, "."); //line:netp:parseuri:beginconvert2
strcat(filename, uri); //line:netp:parseuri:endconvert2
return 0;
}
}
/*
* serve_static - copy a file back to the client
*/
void serve_static(int fd, char *filename, int filesize)
{
int srcfd;
char *srcp, filetype[MAXLINE], buf[MAXBUF];
/* Send response headers to client */
get_filetype(filename, filetype); //line:netp:servestatic:getfiletype
sprintf(buf, "HTTP/1.0 200 OK\r\n"); //line:netp:servestatic:beginserve
sprintf(buf, "%sServer: Tiny Web Server\r\n", buf);
sprintf(buf, "%sConnection: close\r\n", buf);
sprintf(buf, "%sContent-length: %d\r\n", buf, filesize);
sprintf(buf, "%sContent-type: %s\r\n\r\n", buf, filetype);
Rio_writen(fd, buf, strlen(buf)); //line:netp:servestatic:endserve
printf("Response headers:\n");
printf("%s", buf);
/* Send response body to client */
srcfd = Open(filename, O_RDONLY, 0); //line:netp:servestatic:open
srcp = Mmap(0, filesize, PROT_READ, MAP_PRIVATE, srcfd, 0);//line:netp:servestatic:mmap
Close(srcfd); //line:netp:servestatic:close
Rio_writen(fd, srcp, filesize); //line:netp:servestatic:write
Munmap(srcp, filesize); //line:netp:servestatic:munmap
}
/*
* get_filetype - derive file type from file name
*/
void get_filetype(char *filename, char *filetype)
{
if (strstr(filename, ".html"))
strcpy(filetype, "text/html");
else if (strstr(filename, ".gif"))
strcpy(filetype, "image/gif");
else if (strstr(filename, ".png"))
strcpy(filetype, "image/png");
else if (strstr(filename, ".jpg"))
strcpy(filetype, "image/jpeg");
else
strcpy(filetype, "text/plain");
}
/*
* serve_dynamic - run a CGI program on behalf of the client
*/
void serve_dynamic(int fd, char *filename, char *cgiargs)
{
char buf[MAXLINE], *emptylist[] = { NULL };
/* Return first part of HTTP response */
sprintf(buf, "HTTP/1.0 200 OK\r\n");
Rio_writen(fd, buf, strlen(buf));
sprintf(buf, "Server: Tiny Web Server\r\n");
Rio_writen(fd, buf, strlen(buf));
if (Fork() == 0) { /* Child */ //line:netp:servedynamic:fork
/* Real server would set all CGI vars here */
setenv("QUERY_STRING", cgiargs, 1); //line:netp:servedynamic:setenv
Dup2(fd, STDOUT_FILENO); /* Redirect stdout to client */ //line:netp:servedynamic:dup2
Execve(filename, emptylist, environ); /* Run CGI program */ //line:netp:servedynamic:execve
}
}
/*
* clienterror - returns an error message to the client
*/
void clienterror(int fd, char *cause, char *errnum,
char *shortmsg, char *longmsg)
{
char buf[MAXLINE], body[MAXBUF];
/* Build the HTTP response body */
sprintf(body, "Tiny Error ");
sprintf(body, "%s"ffffff"">\r\n", body);
sprintf(body, "%s%s: %s\r\n", body, errnum, shortmsg);
sprintf(body, "%s%s: %s\r\n"
, body, longmsg, cause);
sprintf(body, "%s
The Tiny Web server\r\n", body);
/* Print the HTTP response */
sprintf(buf, "HTTP/1.0 %s %s\r\n", errnum, shortmsg);
Rio_writen(fd, buf, strlen(buf));
sprintf(buf, "Content-type: text/html\r\n");
Rio_writen(fd, buf, strlen(buf));
sprintf(buf, "Content-length: %d\r\n\r\n", (int)strlen(body));
Rio_writen(fd, buf, strlen(buf));
Rio_writen(fd, body, strlen(body));
}P9
@@ -152,12 +152,12 @@
printf("Response headers:\n");
printf("%s", buf);
- /* Send response body to client */
srcfd = Open(filename, O_RDONLY, 0); //line:netp:servestatic:open
- srcp = Mmap(0, filesize, PROT_READ, MAP_PRIVATE, srcfd, 0);//line:netp:servestatic:mmap
+ srcp = (char*)Malloc(filesize);
+ Rio_readn(srcfd, srcp, filesize);
Close(srcfd); //line:netp:servestatic:close
Rio_writen(fd, srcp, filesize); //line:netp:servestatic:write
- Munmap(srcp, filesize); //line:netp:servestatic:munmap
+ free(srcp);
}P10
- A
<html>
<head>
<meta charset="utf-8" />
<title>Tiny Servertitle>
head>
<body>
<form action="/cgi-bin/form-adder" method="GET">
<p>first number: <input type="text" name="first"/>p>
<p>second number: <input type="text" name="second"/>p>
<input type="submit" value="Submit"/>
form>
body>
html>- B
@@ -1,5 +1,5 @@
/*
- * adder.c - a minimal CGI program that adds two numbers together
+ * form-adder.c - a minimal CGI program that adds two numbers together
*/
#include "../csapp.h"
@@ -12,10 +12,8 @@
if ((buf = getenv("QUERY_STRING")) != NULL) {
p = strchr(buf, '&');
*p = '\0';
- strcpy(arg1, buf);
- strcpy(arg2, p+1);
- n1 = atoi(arg1);
- n2 = atoi(arg2);
+ sscanf(buf, "first=%d", &n1);
+ sscanf(p+1, "second=%d", &n2);
}
/* Make the response body */P11
tiny.c更改：
@@ -7,9 +7,9 @@
void doit(int fd);
void read_requesthdrs(rio_t *rp);
int parse_uri(char *uri, char *filename, char *cgiargs);
-void serve_static(int fd, char *filename, int filesize);
+void serve_static(int fd, char *filename, int filesize, char *method);
void get_filetype(char *filename, char *filetype);
-void serve_dynamic(int fd, char *filename, char *cgiargs);
+void serve_dynamic(int fd, char *filename, char *cgiargs, char *method);
void clienterror(int fd, char *cause, char *errnum,
char *shortmsg, char *longmsg);
@@ -55,7 +55,7 @@
return;
printf("%s", buf);
sscanf(buf, "%s %s %s", method, uri, version); //line:netp:doit:parserequest
- if (strcasecmp(method, "GET")) { //line:netp:doit:beginrequesterr
+ if (!(strcasecmp(method, "GET") == 0 || strcasecmp(method, "HEAD") == 0)) {
clienterror(fd, method, "501", "Not Implemented",
"Tiny does not implement this method");
return;
@@ -76,7 +76,7 @@
"Tiny couldn't read the file");
return;
}
- serve_static(fd, filename, sbuf.st_size); //line:netp:doit:servestatic
+ serve_static(fd, filename, sbuf.st_size, method); //line:netp:doit:servestatic
}
else { /* Serve dynamic content */
if (!(S_ISREG(sbuf.st_mode)) || !(S_IXUSR & sbuf.st_mode)) { //line:netp:doit:executable
@@ -84,7 +84,7 @@
"Tiny couldn't run the CGI program");
return;
}
- serve_dynamic(fd, filename, cgiargs); //line:netp:doit:servedynamic
+ serve_dynamic(fd, filename, cgiargs, method); //line:netp:doit:servedynamic
}
}
@@ -136,7 +136,7 @@
/*
* serve_static - copy a file back to the client
*/
-void serve_static(int fd, char *filename, int filesize)
+void serve_static(int fd, char *filename, int filesize, char *method)
{
int srcfd;
char *srcp, filetype[MAXLINE], buf[MAXBUF];
@@ -152,6 +152,9 @@
printf("Response headers:\n");
printf("%s", buf);
+ if (strcasecmp(method, "HEAD") == 0)
+ return;
+
/* Send response body to client */
srcfd = Open(filename, O_RDONLY, 0); //line:netp:servestatic:open
srcp = Mmap(0, filesize, PROT_READ, MAP_PRIVATE, srcfd, 0);//line:netp:servestatic:mmap
@@ -180,7 +183,7 @@
/*
* serve_dynamic - run a CGI program on behalf of the client
*/
-void serve_dynamic(int fd, char *filename, char *cgiargs)
+void serve_dynamic(int fd, char *filename, char *cgiargs, char *method)
{
char buf[MAXLINE], *emptylist[] = { NULL };
@@ -193,6 +196,7 @@
if (Fork() == 0) { /* Child */ //line:netp:servedynamic:fork
/* Real server would set all CGI vars here */
setenv("QUERY_STRING", cgiargs, 1); //line:netp:servedynamic:setenv
+ setenv("REQUEST_METHOD", method, 1);
Dup2(fd, STDOUT_FILENO); /* Redirect stdout to client */ //line:netp:servedynamic:dup2
Execve(filename, emptylist, environ); /* Run CGI program */ //line:netp:servedynamic:execve
}addr.c更改：
@@ -1,10 +1,10 @@
/*
- * adder.c - a minimal CGI program that adds two numbers together
+ * head-adder.c - a minimal CGI program that adds two numbers together
*/
#include "../csapp.h"
int main(void) {
- char *buf, *p;
+ char *buf, *p, *method;
char arg1[MAXLINE], arg2[MAXLINE], content[MAXLINE];
int n1=0, n2=0;
@@ -18,6 +18,8 @@
n2 = atoi(arg2);
}
+ method = getenv("REQUEST_METHOD");
+
/* Make the response body */
sprintf(content, "Welcome to add.com: ");
sprintf(content, "%sTHE Internet addition portal.\r\n"
, content);
@@ -29,7 +31,10 @@
printf("Connection: close\r\n");
printf("Content-length: %d\r\n", (int)strlen(content));
printf("Content-type: text/html\r\n\r\n");
- printf("%s", content);
+
+ if (strcasecmp(method, "HEAD") != 0)
+ printf("%s", content);
+
fflush(stdout);
exit(0);P12
tiny.c
@@ -5,7 +5,7 @@
#include "csapp.h"
void doit(int fd);
-void read_requesthdrs(rio_t *rp);
+int read_requesthdrs(rio_t *rp, char *method);
int parse_uri(char *uri, char *filename, char *cgiargs);
void serve_static(int fd, char *filename, int filesize);
void get_filetype(char *filename, char *filetype);
@@ -55,12 +55,14 @@
return;
printf("%s", buf);
sscanf(buf, "%s %s %s", method, uri, version); //line:netp:doit:parserequest
- if (strcasecmp(method, "GET")) { //line:netp:doit:beginrequesterr
+ if (!(strcasecmp(method, "GET") == 0 || strcasecmp(method, "POST") == 0)) {
clienterror(fd, method, "501", "Not Implemented",
"Tiny does not implement this method");
return;
} //line:netp:doit:endrequesterr
- read_requesthdrs(&rio); //line:netp:doit:readrequesthdrs
+ int param_len = read_requesthdrs(&rio, method);
+
+ Rio_readnb(&rio, buf, param_len);
/* Parse URI from GET request */
is_static = parse_uri(uri, filename, cgiargs); //line:netp:doit:staticcheck
@@ -84,24 +86,29 @@
"Tiny couldn't run the CGI program");
return;
}
- serve_dynamic(fd, filename, cgiargs); //line:netp:doit:servedynamic
+ if (strcasecmp(method, "GET") == 0)
+ serve_dynamic(fd, filename, cgiargs);
+ else
+ serve_dynamic(fd, filename, buf);
}
}
/*
* read_requesthdrs - read HTTP request headers
*/
-void read_requesthdrs(rio_t *rp)
+int read_requesthdrs(rio_t *rp, char *method)
{
char buf[MAXLINE];
+ int len = 0;
- Rio_readlineb(rp, buf, MAXLINE);
- printf("%s", buf);
- while(strcmp(buf, "\r\n")) { //line:netp:readhdrs:checkterm
+ do {
Rio_readlineb(rp, buf, MAXLINE);
printf("%s", buf);
- }
- return;
+ if (strcasecmp(method, "POST") == 0 && strncasecmp(buf, "Content-Length:", 15) == 0)
+ sscanf(buf, "Content-Length: %d", &len);
+ } while(strcmp(buf, "\r\n"));
+
+ return len;post-addr
@@ -1,5 +1,5 @@
/*
- * adder.c - a minimal CGI program that adds two numbers together
+ * post-adder.c - a minimal CGI program that adds two numbers together
*/
#include "../csapp.h"
@@ -12,10 +12,8 @@
if ((buf = getenv("QUERY_STRING")) != NULL) {
p = strchr(buf, '&');
*p = '\0';
- strcpy(arg1, buf);
- strcpy(arg2, p+1);
- n1 = atoi(arg1);
- n2 = atoi(arg2);
+ sscanf(buf, "first=%d", &n1);
+ sscanf(p+1, "second=%d", &n2);
}P13
@@ -13,6 +13,17 @@
void clienterror(int fd, char *cause, char *errnum,
char *shortmsg, char *longmsg);
+// improved rio written
+void Im_rio_writen(int fd, void *usrbuf, size_t n) {
+ if (rio_writen(fd, usrbuf, n) != n) {
+ if (errno == EPIPE)
+ fprintf(stderr, "EPIPE error");
+
+ fprintf(stderr, "%s ", strerror(errno));
+ unix_error("client side has ended connection");
+ }
+}
+
int main(int argc, char **argv)
{
int listenfd, connfd;
@@ -26,6 +37,9 @@
exit(1);
}
+ if (Signal(SIGPIPE, SIG_IGN) == SIG_ERR)
+ unix_error("mask signal pipe error");
+
listenfd = Open_listenfd(argv[1]);
while (1) {
clientlen = sizeof(clientaddr);
@@ -148,7 +162,7 @@
sprintf(buf, "%sConnection: close\r\n", buf);
sprintf(buf, "%sContent-length: %d\r\n", buf, filesize);
sprintf(buf, "%sContent-type: %s\r\n\r\n", buf, filetype);
- Rio_writen(fd, buf, strlen(buf)); //line:netp:servestatic:endserve
+ Im_rio_writen(fd, buf, strlen(buf)); //line:netp:servestatic:endserve
printf("Response headers:\n");
printf("%s", buf);
@@ -156,7 +170,7 @@
srcfd = Open(filename, O_RDONLY, 0); //line:netp:servestatic:open
srcp = Mmap(0, filesize, PROT_READ, MAP_PRIVATE, srcfd, 0);//line:netp:servestatic:mmap
Close(srcfd); //line:netp:servestatic:close
- Rio_writen(fd, srcp, filesize); //line:netp:servestatic:write
+ Im_rio_writen(fd, srcp, filesize); //line:netp:servestatic:write
Munmap(srcp, filesize); //line:netp:servestatic:munmap
}
@@ -186,11 +200,13 @@
/* Return first part of HTTP response */
sprintf(buf, "HTTP/1.0 200 OK\r\n");
- Rio_writen(fd, buf, strlen(buf));
+ Im_rio_writen(fd, buf, strlen(buf));
sprintf(buf, "Server: Tiny Web Server\r\n");
- Rio_writen(fd, buf, strlen(buf));
+ Im_rio_writen(fd, buf, strlen(buf));
if (Fork() == 0) { /* Child */ //line:netp:servedynamic:fork
+ if (Signal(SIGPIPE, SIG_DFL) == SIG_ERR)
+ unix_error("unmask signal pipe error");
/* Real server would set all CGI vars here */
setenv("QUERY_STRING", cgiargs, 1); //line:netp:servedynamic:setenv
Dup2(fd, STDOUT_FILENO); /* Redirect stdout to client */ //line:netp:servedynamic:dup2
@@ -216,10 +232,10 @@
/* Print the HTTP response */
sprintf(buf, "HTTP/1.0 %s %s\r\n", errnum, shortmsg);
- Rio_writen(fd, buf, strlen(buf));
+ Im_rio_writen(fd, buf, strlen(buf));
sprintf(buf, "Content-type: text/html\r\n");
- Rio_writen(fd, buf, strlen(buf));
+ Im_rio_writen(fd, buf, strlen(buf));
sprintf(buf, "Content-length: %d\r\n\r\n", (int)strlen(body));
- Rio_writen(fd, buf, strlen(buf));
- Rio_writen(fd, body, strlen(body));
+ Im_rio_writen(fd, buf, strlen(buf));
+ Im_rio_writen(fd, body, strlen(body));
}