linux下的http服务

/* code c, change the DEFAULTIP to your localhost IP*/

#include <stdarg.h>
#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <errno.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <resolv.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <signal.h>
#include <getopt.h>


#define DEFAULTIP "127.0.0.1"
#define DEFAULTPORT "80"
#define DEFAULTBACK "10"
#define DEFAULTDIR "/home"
#define DEFAULTLOG "/tmp/das-server.log"

void prterrmsg(char *msg);
#define prterrmsg(msg)        { perror(msg); abort(); }
void wrterrmsg(char *msg);
#define wrterrmsg(msg)        { fputs(msg, logfp); fputs(strerror(errno), logfp);fflush(logfp); abort(); }


void prtinfomsg(char *msg);
#define prtinfomsg(msg)        { fputs(msg, stdout);  }
void wrtinfomsg(char *msg);
#define wrtinfomsg(msg)        {  fputs(msg, logfp); fflush(logfp);}


#define MAXBUF        1024
 
char buffer[MAXBUF + 1];
char *host = 0;
char *port = 0;
char *back = 0;
char *dirroot = 0;
char *logdir = 0;
unsigned char daemon_y_n = 0;
FILE *logfp;


#define MAXPATH        150


/*----------------------------------------
*--- dir_up - 查找dirpath所指目录的上一级目录
*----------------------------------------
*/
char *dir_up(char *dirpath)
{
     static char Path[MAXPATH];
     int len;
 
     strcpy(Path, dirpath);
     len = strlen(Path);
     if (len > 1 && Path[len - 1] == '/')
         len--;
     while (Path[len - 1] != '/' && len > 1)
         len--;
     Path[len] = 0;
     return Path;
}


 /*------------------------------------------------------
 *--- AllocateMemory - 分配空间并把d所指的内容复制
   *------------------------------------------------------
 */
 void AllocateMemory(char **s, int l, char *d)
 {
     *s = malloc(l + 1);
     bzero(*s, l + 1);
     memcpy(*s, d, l);
 }
 /************关于本文档********************************************
 *filename: das-server.c
 *purpose: 这是在Linux下用C语言写的目录访问服务器,支持目录浏览和文件下载
 
 *********************************************************************/
 /*------------------------------------------------------
 *--- GiveResponse - 把Path所指的内容发送到client_sock去
 *-------------------如果Path是一个目录,则列出目录内容
 *-------------------如果Path是一个文件,则下载文件
 *------------------------------------------------------
 */
 void GiveResponse(FILE * client_sock, char *Path)
 {
     struct dirent *dirent;
     struct stat info;
     char Filename[MAXPATH];
     DIR *dir;
     int fd, len, ret;
     char *p, *realPath, *realFilename, *nport;

     /* 获得实际工作目录或文件 */
     len = strlen(dirroot) + strlen(Path) + 1;
     realPath = malloc(len + 1);
     bzero(realPath, len + 1);
     sprintf(realPath, "%s/%s", dirroot, Path);

     /* 获得实际工作端口 */
     len = strlen(port) + 1;
     nport = malloc(len + 1);
    bzero(nport, len + 1);
     sprintf(nport, ":%s", port);

     /* 获得实际工作目录或文件的信息以判断是文件还是目录 */
    if (stat(realPath, &info)) {
         fprintf(client_sock,
                 "HTTP/1.1 200 OK\r\nServer:SONG\r\nConnection: close\r\nContent-Type:text/html; charset=UTF-8\r\n\r\n<html><head><title>%d - %s</title></head>"
                 "<body><font size=+4>Linux 下目录访问服务器</font><br><hr width=\"100%%\"><br><center>"
                 "<table border cols=3 width=\"100%%\">", errno,
                 strerror(errno));
         fprintf(client_sock,
                 "</table><font color=\"CC0000\" size=+2>请向管理员咨询为何出现如下错误提示:\n%s %s</font></body></html>",
                 Path, strerror(errno));
         goto out;
     }
     /* 处理浏览文件请求,即下载文件 */
    if (S_ISREG(info.st_mode)) {
         fd = open(realPath, O_RDONLY);
         len = lseek(fd, 0, SEEK_END);
         p = (char *) malloc(len + 1);
         bzero(p, len + 1);
         lseek(fd, 0, SEEK_SET);
         ret = read(fd, p, len);
         close(fd);
         fprintf(client_sock,
                 "HTTP/1.1 200 OK\r\nServer:SONG\r\nConnection: keep-alive\r\nContent-type: application/*\r\nContent-Length:%d\r\n\r\n",
                 len);
         fwrite(p, len, 1, client_sock);
        free(p);
     } else if (S_ISDIR(info.st_mode)) {
         /* 处理浏览目录请求 */
         dir = opendir(realPath);
         fprintf(client_sock,
                 "HTTP/1.1 200 OK\r\nServer:SONG\r\nConnection: close\r\nContent-Type:text/html; charset=UTF-8\r\n\r\n<html><head><title>%s</title></head>"
                 "<body><font size=+4>Linux 下目录访问服务器</font><br><hr width=\"100%%\"><br><center>"
                 "<table border cols=3 width=\"100%%\">", Path);
         fprintf(client_sock,
                 "<caption><font size=+3>目录 %s</font></caption>\n",
                 Path);
         fprintf(client_sock,
                 "<tr><td>名称</td><td>大小</td><td>修改时间</td></tr>\n");
         if (dir == 0) {
             fprintf(client_sock,
                     "</table><font color=\"CC0000\" size=+2>%s</font></body></html>",
                     strerror(errno));
             return;
         }
         /* 读取目录里的所有内容 */
         while ((dirent = readdir(dir)) != 0) {
             if (strcmp(Path, "/") == 0)
                 sprintf(Filename, "/%s", dirent->d_name);
             else
                 sprintf(Filename, "%s/%s", Path, dirent->d_name);
             fprintf(client_sock, "<tr>");
             len = strlen(dirroot) + strlen(Filename) + 1;
             realFilename = malloc(len + 1);
             bzero(realFilename, len + 1);
             sprintf(realFilename, "%s/%s", dirroot, Filename);
             if (stat(realFilename, &info) == 0) {
                 if (strcmp(dirent->d_name, "..") == 0)
                     fprintf(client_sock,
                             "<td><a href=\"http://%s%s%s\">(parent)</a></td>",
                             host, atoi(port) == 80 ? "" : nport,
                             dir_up(Path));
                 else
                     fprintf(client_sock,
                             "<td><a href=\"http://%s%s%s\">%s</a></td>",
                             host, atoi(port) == 80 ? "" : nport, Filename,
                             dirent->d_name);
                 if (S_ISDIR(info.st_mode))
                    fprintf(client_sock, "<td>目录</td>");
                else if (S_ISREG(info.st_mode))
                    fprintf(client_sock, "<td>%d</td>", info.st_size);
                 else if (S_ISLNK(info.st_mode))
                     fprintf(client_sock, "<td>链接</td>");
                 else if (S_ISCHR(info.st_mode))
                     fprintf(client_sock, "<td>字符设备</td>");
                 else if (S_ISBLK(info.st_mode))
                     fprintf(client_sock, "<td>块设备</td>");
                else if (S_ISFIFO(info.st_mode))
                     fprintf(client_sock, "<td>FIFO</td>");
                 else if (S_ISSOCK(info.st_mode))
                     fprintf(client_sock, "<td>Socket</td>");
                 else
                     fprintf(client_sock, "<td>(未知)</td>");
                 fprintf(client_sock, "<td>%s</td>", ctime(&info.st_ctime));
             }
             fprintf(client_sock, "</tr>\n");
             free(realFilename);
         }
        fprintf(client_sock, "</table></center></body></html>");
     } else {
         /* 既非常规文件又非目录,禁止访问 */
         fprintf(client_sock,
                "HTTP/1.1 200 OK\r\nServer:SONG\r\nConnection: close\r\nContent-Type:text/html; charset=UTF-8\r\n<html><head><title>permission denied</title></head>"
                "<body><font size=+4>Linux 下目录访问服务器</font><br><hr width=\"100%%\"><br><center>"
                 "<table border cols=3 width=\"100%%\">");
         fprintf(client_sock,
                 "</table><font color=\"CC0000\" size=+2>你访问的资源'%s'被禁止访问,请联系管理员解决!</font></body></html& gt;",
                 Path);
     }
   out:
     free(realPath);
     free(nport);
 }

 /*------------------------------------------------------
*--- getoption - 分析取出程序的参数
 *------------------------------------------------------
*/
void getoption(int argc, char **argv)
{
     int c, len;
     char *p = 0;

     opterr = 0;
     while (1) {
         int option_index = 0;
        static struct option long_options[] = {
            {"host", 1, 0, 0},
            {"port", 1, 0, 0},
            {"back", 1, 0, 0},
            {"dir", 1, 0, 0},
            {"log", 1, 0, 0},
            {"daemon", 0, 0, 0},
                         {0, 0, 0, 0}
                     };
         /* 本程序支持如一些参数:
          * --host IP地址 或者 -H IP地址
          * --port 端口 或者 -P 端口
          * --back 监听数量 或者 -B 监听数量
          * --dir 网站根目录 或者 -D 网站根目录
          * --log 日志存放路径 或者 -L 日志存放路径
          * --daemon 使程序进入后台运行模式
          */
         c = getopt_long(argc, argv, "H:P:B:D:L",
                         long_options, &option_index);
         if (c == -1 || c == '?')
            break;

         if(optarg)        len = strlen(optarg);
         else        len = 0;

         if ((!c && !(strcasecmp(long_options[option_index].name, "host")))
            || c == 'H')
             p = host = malloc(len + 1);
        else if ((!c
                   &&
                   !(strcasecmp(long_options[option_index].name, "port")))
                  || c == 'P')
             p = port = malloc(len + 1);
         else if ((!c
                   &&
                  !(strcasecmp(long_options[option_index].name, "back")))
                 || c == 'B')
             p = back = malloc(len + 1);
        else if ((!c
                   && !(strcasecmp(long_options[option_index].name, "dir")))
                  || c == 'D')
            p = dirroot = malloc(len + 1);
        else if ((!c
                  && !(strcasecmp(long_options[option_index].name, "log")))
                  || c == 'L')
             p = logdir = malloc(len + 1);
        else if ((!c
                   &&
                   !(strcasecmp
                    (long_options[option_index].name, "daemon")))) {
             daemon_y_n = 1;
             continue;
         }
         else
             break;
         bzero(p, len + 1);
         memcpy(p, optarg, len);
     }
 }

 int main(int argc, char **argv)
 {
     struct sockaddr_in addr;
     struct sockaddr_in my_addr;
     my_addr.sin_addr.s_addr=htonl(INADDR_ANY);
     int sock_fd, addrlen;

     /* 获得程序工作的参数,如 IP 、端口、监听数、网页根目录、目录存放位置等 */
    getoption(argc, argv);

     if (!host) {
         addrlen = strlen(DEFAULTIP);
         AllocateMemory(&host, addrlen,DEFAULTIP);
     }
     if (!port) {
         addrlen = strlen(DEFAULTPORT);
         AllocateMemory(&port, addrlen, DEFAULTPORT);
     }
     if (!back) {
         addrlen = strlen(DEFAULTBACK);
         AllocateMemory(&back, addrlen, DEFAULTBACK);
     }
    if (!dirroot) {
         addrlen = strlen(DEFAULTDIR);
         AllocateMemory(&dirroot, addrlen, DEFAULTDIR);
     }
     if (!logdir) {
         addrlen = strlen(DEFAULTLOG);
         AllocateMemory(&logdir, addrlen, DEFAULTLOG);
     }


    printf
         ("host=%s port=%s back=%s dirroot=%s logdir=%s %s是后台工作模式(进程ID:%d)\n",
          host, port, back, dirroot, logdir, daemon_y_n?"":"不", getpid());

     /* fork() 两次处于后台工作模式下 */
     if (daemon_y_n) {
        if (fork())
            exit(0);
         if (fork())
            exit(0);
        close(0), close(1), close(2);
         logfp = fopen(logdir, "a+");
         if (!logfp)
             exit(0);
     }

     /* 处理子进程退出以免产生僵尸进程 */
    signal(SIGCHLD, SIG_IGN);

     /* 创建 socket */
    if ((sock_fd = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
        if (!daemon_y_n) {
             prterrmsg("socket()");
         } else {
            wrterrmsg("socket()");
        }
     }

     /* 设置端口快速重用 */
    addrlen = 1;
     setsockopt(sock_fd, SOL_SOCKET, SO_REUSEADDR, &addrlen,
                sizeof(addrlen));

     addr.sin_family = AF_INET;
    addr.sin_port = htons(atoi(port));
    addr.sin_addr.s_addr = inet_addr(host);
    addrlen = sizeof(struct sockaddr_in);
    /* 绑定地址、端口等信息 */
     if (bind(sock_fd, (struct sockaddr *) &addr, addrlen) < 0) {
        if (!daemon_y_n) {
            prterrmsg("bind()");
         } else {
             wrterrmsg("bind()");
         }
     }

     /* 开启临听 */
    if (listen(sock_fd, atoi(back)) < 0) {
        if (!daemon_y_n) {
             prterrmsg("listen()");
        } else {
            wrterrmsg("listen()");
         }
     }
     while (1) {
         int len;
         int new_fd;
       addrlen = sizeof(struct sockaddr_in);
         /* 接受新连接请求 */
        new_fd = accept(sock_fd, (struct sockaddr *) &addr, &addrlen);
        if (new_fd < 0)
            {
            if (!daemon_y_n)
                {
                 prterrmsg("accept()");
                        }
                else {
                wrterrmsg("accept()");
                         }
            break;
                 }
        bzero(buffer, MAXBUF + 1);
        sprintf(buffer, "连接来自于: %s:%d\n",inet_ntoa(addr.sin_addr), ntohs(addr.sin_port));
        if (!daemon_y_n)
            {
             prtinfomsg(buffer);
                 }
            else
            {
             wrtinfomsg(buffer);
                 }
         /* 产生一个子进程去处理请求,当前进程继续等待新的连接到来 */
        if (!fork())
            {
             bzero(buffer, MAXBUF + 1);
            if ((len = recv(new_fd, buffer, MAXBUF, 0)) > 0)
                {
                FILE *ClientFP = fdopen(new_fd, "w");
               if (ClientFP == NULL)
                    {
                   if (!daemon_y_n)
                        {
                            prterrmsg("fdopen()");
                                   }
                        else
                        {
                      prterrmsg("fdopen()");
                                     }
                             }
                    else
                    {
                   char Req[MAXPATH + 1] = "";
                   sscanf(buffer, "GET %s HTTP", Req);
                   bzero(buffer, MAXBUF + 1);
                   sprintf(buffer, "请求取文件: \"%s\"\n", Req);
                   if (!daemon_y_n)
                        {
                       prtinfomsg(buffer);
                                     }
                        else
                         {
                       wrtinfomsg(buffer);
                                     }
                     /* 处理用户请求 */
                  GiveResponse(ClientFP, Req);
                  fclose(ClientFP);
                             }
                         }
             exit(0);
                }
        close(new_fd);
     }
    close(sock_fd);
     return 0;
 }

原文地址:https://www.cnblogs.com/BloodAndBone/p/1850974.html