Linux 用epoll实现的简单http服务器
main.c
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
#include "epoll.h"
int main(int argc, char** argv){
if(argc != 3){
printf("eg. port resource_path\n");
exit(1);
}
int port = atoi(argv[1]);
int ret = chdir(argv[2]);
if(ret == -1){
perror("chdir error");
exit(1);
}
int lfd = socket(AF_INET, SOCK_STREAM, 0);
struct sockaddr_in addr;
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = htonl(INADDR_ANY);
ret = bind(lfd, (struct sockaddr*)&addr, sizeof(addr));
if(ret == -1){
perror("bind err");
exit(1);
}
listen(lfd, 64);
epoll_run(lfd);
}
epoll.h
#define EVENT_MAX 1024
void epoll_run(int lfd);
void do_accept(int lfd, int efd);
void do_read(int cfd, int efd);
int get_line(int sock, char *buf, int size);
void http_get_request(const char* line, int cfd);
void send_respond_head(int cfd, int no, const char* desp, const char* type, long len);
const char *get_file_type(const char *name);
void send_file(int cfd, const char* path);
void disconnect(int cfd, int epfd);
void send_dir(int cfd, const char* path);
void encode_str(char* to, int tosize, const char* from);
void decode_str(char *to, char *from);
epoll.c
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/epoll.h>
#include "epoll.h"
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <dirent.h>
#include <ctype.h>
void epoll_run(int lfd){
int efd = epoll_create(EVENT_MAX);
if(efd == -1){
perror("epoll_create err");
exit(1);
}
struct epoll_event ev;
ev.events = EPOLLIN;
ev.data.fd = lfd;
int ret = epoll_ctl(efd, EPOLL_CTL_ADD, lfd, &ev);
if(ret == -1){
perror("epoll_ctl err");
exit(1);
}
struct epoll_event evs[EVENT_MAX];
while(1){
ret = epoll_wait(efd, evs, EVENT_MAX, -1);
if(ret == -1){
perror("epoll_wait err");
exit(1);
}
for(int i = 0; i < ret; ++i){
if(evs[i].data.fd == lfd){
do_accept(lfd, efd);
}
else {
do_read(evs[i].data.fd, efd);
}
}
}
}
void do_read(int cfd, int efd){
char line[1024];
int len = get_line(cfd, line, sizeof(line));
printf("head:%s", line);
while(len){
char buf[1024];
len = get_line(cfd, buf, sizeof buf);
printf("%s", buf);
}
if(strncasecmp("get", line, 3) == 0){
http_get_request(line, cfd);
disconnect(cfd, efd);
}
}
void http_get_request(const char* line, int cfd){
char method[12] = {0};
char res[1024] = {0};
sscanf(line, "%[^ ] %[^ ]", method, res);
// 转码 将不能识别的中文乱码 - > 中文
// 解码 %23 %34 %5f
char destr[1024];
decode_str(destr, res);
// 处理path /xx
// 去掉path中的/
char* file = destr + 1;
char fbuf[1024];
if(strcmp(res, "/") == 0){
file = "./";
//getcwd(fbuf, sizeof(fbuf));
//printf("root:[%s]\n", fbuf);
// file = fbuf;
}
struct stat st;
printf("file:[%s]\n", file);
int ret = stat(file, &st);
if(ret == -1){
//todo 404
perror("stat error");
exit(1);
}
if(S_ISDIR(st.st_mode)){
//dir
// 发送头信息
send_respond_head(cfd, 200, "OK", get_file_type(".html"), 100000);
send_dir(cfd, file);
}
else if(S_ISREG(st.st_mode)){
//reg file
send_respond_head(cfd, 200, "OK", get_file_type(file), st.st_size);
send_file(cfd, file);
}
}
void send_dir(int cfd, const char* path){
char file[1024] = {0};
char buf[4096] = {0};
sprintf(buf, "<html><head><title>目录名: %s</title></head>", path);
sprintf(buf+strlen(buf), "<body><h1>当前目录: %s</h1><table>", path);
#if 1
DIR* dir = opendir(path);
if(dir == NULL){
perror("opendir error");
exit(1);
}
// 读目录
char enstr[1024] = {0};
struct dirent* ptr = NULL;
while((ptr = readdir(dir)) != NULL){
char* name = ptr->d_name;
// 拼接文件的完整路径
sprintf(file, "%s/%s", path, name);
encode_str(enstr, sizeof(enstr), name);
struct stat st;
int ret = stat(file, &st);
if(ret == -1){
perror("stat err");
exit(1);
}
// 如果是文件
if(S_ISREG(st.st_mode)){
sprintf(buf+strlen(buf),
"<tr><td><a href=\"%s\">%s</a></td><td>%ld</td></tr>",
enstr, name, (long)st.st_size);
}
// 如果是目录
else if(S_ISDIR(st.st_mode)){
sprintf(buf+strlen(buf),
"<tr><td><a href=\"%s/\">%s/</a></td><td>%ld</td></tr>",
enstr, name, (long)st.st_size);
}
send(cfd, buf, strlen(buf), 0);
memset(buf, 0, sizeof(buf));
}
sprintf(buf+strlen(buf), "</table></body></html>");
send(cfd, buf, strlen(buf), 0);
#endif
}
// 断开连接的函数
void disconnect(int cfd, int epfd){
int ret = epoll_ctl(epfd, EPOLL_CTL_DEL, cfd, NULL);
if(ret == -1){
perror("epoll_ctl del cfd error");
exit(1);
}
close(cfd);
}
void send_file(int cfd, const char* path){
int fd = open(path, O_RDONLY);
if(fd == -1){
//todo 404
perror("open err");
exit(1);
}
char buf[4096];
int ret = 0;
while((ret = read(fd, buf, sizeof buf)) > 0){
send(cfd, buf, ret, 0);
}
if(ret == -1){
perror("read err");
exit(1);
}
close(fd);
}
void send_respond_head(int cfd, int no, const char* desp, const char* type, long len){
char buf[1024] = {0};
// 状态行
sprintf(buf, "http/1.1 %d %s\r\n", no, desp);
send(cfd, buf, strlen(buf), 0);
// 消息报头
memset(buf, 0, sizeof buf);
sprintf(buf, "Content-Type:%s\r\n", type);
sprintf(buf+strlen(buf), "Content-Length:%ld\r\n", len);
send(cfd, buf, strlen(buf), 0);
// 空行
send(cfd, "\r\n", 2, 0);
}
void do_accept(int lfd, int efd){
struct sockaddr_in cli;
socklen_t len = sizeof(cli);;
int cfd = accept(lfd, (struct sockaddr*)&cli, &len);
if(cfd == -1){
perror("accept err");
exit(1);
}
//set nonblock socket
int flag = fcntl(cfd, F_GETFL);
flag |= O_NONBLOCK;
fcntl(cfd, F_SETFL, flag);
struct epoll_event ev;
ev.events = EPOLLIN | EPOLLET;
ev.data.fd = cfd;
int ret = epoll_ctl(efd, EPOLL_CTL_ADD, cfd, &ev);
if(ret == -1){
perror("epoll_ctl err");
exit(1);
}
}
// 解析http请求消息的每一行内容
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);
if (n > 0){
if (c == '\r'){
n = recv(sock, &c, 1, MSG_PEEK);
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;
}
// 通过文件名获取文件的类型
const char *get_file_type(const char *name){
char* dot;
// 自右向左查找‘.’字符, 如不存在返回NULL
dot = strrchr(name, '.');
if (dot == NULL)
return "text/plain; charset=utf-8";
if (strcmp(dot, ".html") == 0 || strcmp(dot, ".htm") == 0)
return "text/html; charset=utf-8";
if (strcmp(dot, ".jpg") == 0 || strcmp(dot, ".jpeg") == 0)
return "image/jpeg";
if (strcmp(dot, ".gif") == 0)
return "image/gif";
if (strcmp(dot, ".png") == 0)
return "image/png";
if (strcmp(dot, ".css") == 0)
return "text/css";
if (strcmp(dot, ".au") == 0)
return "audio/basic";
if (strcmp( dot, ".wav" ) == 0)
return "audio/wav";
if (strcmp(dot, ".avi") == 0)
return "video/x-msvideo";
if (strcmp(dot, ".mov") == 0 || strcmp(dot, ".qt") == 0)
return "video/quicktime";
if (strcmp(dot, ".mpeg") == 0 || strcmp(dot, ".mpe") == 0)
return "video/mpeg";
if (strcmp(dot, ".vrml") == 0 || strcmp(dot, ".wrl") == 0)
return "model/vrml";
if (strcmp(dot, ".midi") == 0 || strcmp(dot, ".mid") == 0)
return "audio/midi";
if (strcmp(dot, ".mp3") == 0)
return "audio/mpeg";
if (strcmp(dot, ".ogg") == 0)
return "application/ogg";
if (strcmp(dot, ".pac") == 0)
return "application/x-ns-proxy-autoconfig";
return "text/plain; charset=utf-8";
}
// 16进制数转化为10进制
int hexit(char c)
{
if (c >= '0' && c <= '9')
return c - '0';
if (c >= 'a' && c <= 'f')
return c - 'a' + 10;
if (c >= 'A' && c <= 'F')
return c - 'A' + 10;
return 0;
}
/*
* 这里的内容是处理%20之类的东西！是"解码"过程。
* %20 URL编码中的‘ ’(space)
* %21 '!' %22 '"' %23 '#' %24 '$'
* %25 '%' %26 '&' %27 ''' %28 '('......
* 相关知识html中的‘ ’(space)是 
*/
void encode_str(char* to, int tosize, const char* from)
{
int tolen;
for (tolen = 0; *from != '\0' && tolen + 4 < tosize; ++from)
{
if (isalnum(*from) || strchr("/_.-~", *from) != (char*)0)
{
*to = *from;
++to;
++tolen;
}
else
{
sprintf(to, "%%%02x", (int) *from & 0xff);
to += 3;
tolen += 3;
}
}
*to = '\0';
}
void decode_str(char *to, char *from)
{
for ( ; *from != '\0'; ++to, ++from )
{
if (from[0] == '%' && isxdigit(from[1]) && isxdigit(from[2]))
{
*to = hexit(from[1])*16 + hexit(from[2]);
from += 2;
}
else
{
*to = *from;
}
}
*to = '\0';
}