#include "main.h"
#include "http_proxy.h"
#include "http_request.h"
#include "timeout.h"
#include "conf.h"
#include "kill.h"
#include "help.h"
#include "httpdns.h"

#define SERVER_STOP 1
#define SERVER_RELOAD 2
#define SERVER_STATUS 3

struct epoll_event ev, events[MAX_CONNECTION + 1];
int epollfd, server_sock, server_sock6;
conn cts[MAX_CONNECTION];
int local_port;
char local_host[128];
int process;

int create_connection(char *remote_host, int remote_port)
{
    struct sockaddr_in server_addr;
    struct hostent *server;
    int sock = -1;
    server = NULL;
    if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        perror("socket");
        return -1;
    }

    if ((server = gethostbyname(remote_host)) == NULL) {
        perror("gethostbyname");
        errno = EFAULT;
        return -1;
    }

    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    memmove(&server_addr.sin_addr.s_addr, server->h_addr, server->h_length);
    server_addr.sin_port = htons(remote_port);
    if (connect(sock, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        perror("connect");
        close(sock);
        return -1;
    }

    fcntl(sock, F_SETFL, O_NONBLOCK);
    return sock;
}

int check_ipversion(char * address)
{
/* Check for valid IPv4 or Iv6 string. Returns AF_INET for IPv4, AF_INET6 for IPv6 */

    struct in6_addr bindaddr;

    if (inet_pton(AF_INET, address, &bindaddr) == 1) {
         return AF_INET;
    } else {
        if (inet_pton(AF_INET6, address, &bindaddr) == 1) {
            return AF_INET6;
        }
    }
    return 0;
}

int create_connection6(char *remote_host, int remote_port) {
    struct addrinfo hints, *res=NULL;
    int sock;
    int validfamily=0;
    char portstr[12];

    memset(&hints, 0x00, sizeof(hints));

    hints.ai_flags    = AI_NUMERICSERV; /* numeric service number, not resolve */
    hints.ai_family   = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;

    sprintf(portstr, "%d", remote_port);

    /* check for numeric IP to specify IPv6 or IPv4 socket */
    if ((validfamily = check_ipversion(remote_host)) != 0) {
         hints.ai_family = validfamily;
         hints.ai_flags |= AI_NUMERICHOST;  /* remote_host是有效的数字ip，请跳过解析 */
    }

    /* 检查指定的主机是否有效。 如果remote_host是主机名，请尝试解析地址 */
    if (getaddrinfo(remote_host, portstr , &hints, &res) != 0) {
        errno = EFAULT;
        return -1;
    }

    if ((sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) < 0) {
        return -1;
    }

    if (connect(sock, res->ai_addr, res->ai_addrlen) < 0) {
        return -1;
    }

    if (res != NULL)
      freeaddrinfo(res);

    fcntl(sock, F_SETFL, O_NONBLOCK);
    return sock;
}

/*
int create_connection6(char *remote_host, int remote_port)
{
    char port[270];
    int sock = -1;
    struct addrinfo *result;
    struct addrinfo hints;
    bzero(&hints, sizeof(hints));
    hints.ai_family = AF_UNSPEC;
    
    memset(port, 0, 270);
    sprintf(port, "%d", remote_port);       // 转为字符串
    if ((getaddrinfo(remote_host, port, &hints, &result)) != 0)
        return -1;

    //printf("%d\n", result->ai_addrlen);
    switch (result->ai_family) {
    case AF_INET:{
                sock = socket(result->ai_family, result->ai_socktype, result->ai_protocol);
                if (connect(sock, result->ai_addr, result->ai_addrlen) < 0) {
                    perror("AF_INET connect");
                    close(sock);
                    return -1;
                }
            break;
        }
    case AF_INET6:{
                sock = socket(result->ai_family, result->ai_socktype, result->ai_protocol);
                if (connect(sock, result->ai_addr, result->ai_addrlen) < 0) {
                    perror("AF_INET6 connect");
                    return -1;
                }
            break;
        }
    default:
        printf("Unknown\n");
        break;
    }
    freeaddrinfo(result);
    fcntl(sock, F_SETFL, O_NONBLOCK);
    return sock;
}
*/

int create_server_socket(int port)
{
    int server_sock;
    int optval = 1;
    struct sockaddr_in server_addr;
    if ((server_sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        perror("socket");
        return -1;
    }
    if (setsockopt(server_sock, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval)) < 0) {
        perror("setsockopt");
        return -1;
    }
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(port);
    server_addr.sin_addr.s_addr = INADDR_ANY;
    if (bind(server_sock, (struct sockaddr *)&server_addr, sizeof(server_addr)) != 0) {
        perror("bind");
        return -1;
    }
    if (listen(server_sock, 50) < 0) {
        perror("listen");
        return -1;
    }
    return server_sock;
}

int create_server_socket6(int port)
{
    int server_sock;
    int optval = SO_REUSEADDR;
    struct sockaddr_in6 server_addr;
    if ((server_sock = socket(AF_INET6, SOCK_STREAM, 0)) < 0) {
        perror("socket");
        return -1;
    }

    if (setsockopt(server_sock, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval)) < 0) {
        perror("setsockopt");
        return -1;
    }

    if (setsockopt(server_sock, IPPROTO_IPV6, IPV6_V6ONLY, &optval, sizeof(optval)) < 0) {
        perror("setsockopt");
        return -1;
    }

    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin6_family = AF_INET6;
    server_addr.sin6_port = htons(port);
    server_addr.sin6_addr = in6addr_any;

    if (bind(server_sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr_in6)) != 0) {
        perror("bind");
        return -1;
    }

    if (listen(server_sock, 20) < 0) {
        perror("listen");
        return -1;
    }

    return server_sock;
}

void accept_client()
{
    struct epoll_event epollEvent;
    struct sockaddr_in addr;
    conn *client;
    socklen_t addr_len = sizeof(addr);

    // 偶数为客户端,奇数为服务端
    for (client = cts; client - cts < MAX_CONNECTION; client += 2)
        if (client->fd < 0)
            break;
    if (client - cts >= MAX_CONNECTION)
        return;
    client->timer = (client + 1)->timer = 0;
    client->fd = accept(server_sock, (struct sockaddr *)&addr, &addr_len);
    if (client->fd < 0)
        return;
    fcntl(client->fd, F_SETFL, O_NONBLOCK);
    epollEvent.events = EPOLLIN | EPOLLET;
    epollEvent.data.ptr = client;
    epoll_ctl(epollfd, EPOLL_CTL_ADD, client->fd, &epollEvent);
}

void accept_client6()
{
    struct epoll_event epollEvent;
    struct sockaddr_in6 addr;
    conn *client;
    socklen_t addr_len = sizeof(addr);

    // 偶数为客户端,奇数为服务端
    for (client = cts; client - cts < MAX_CONNECTION; client += 2)
        if (client->fd < 0)
            break;
    if (client - cts >= MAX_CONNECTION)
        return;
    client->timer = (client + 1)->timer = 0;
    client->fd = accept(server_sock6, (struct sockaddr *)&addr, &addr_len);
    if (client->fd < 0)
        return;
    fcntl(client->fd, F_SETFL, O_NONBLOCK);
    epollEvent.events = EPOLLIN | EPOLLET;
    epollEvent.data.ptr = client;
    epoll_ctl(epollfd, EPOLL_CTL_ADD, client->fd, &epollEvent);
}

void *http_proxy_loop(void *p)
{
    conf *configure = (conf *) p;
    int n;

    while (1) {
        n = epoll_wait(epollfd, events, MAX_CONNECTION, -1);
        while (n-- > 0) {
            if (events[n].data.fd == server_sock) {
                accept_client();
            }
            else if (events[n].data.fd == server_sock6) {
                accept_client6();
            } else {
                if (events[n].events & EPOLLIN) {
                    tcp_in((conn *) events[n].data.ptr, configure);
                }
                if (events[n].events & EPOLLOUT) {
                    tcp_out((conn *) events[n].data.ptr);
                }
            }
        }
    }
    close(epollfd);
    return NULL;
}

void *start_server(conf * configure)
{
    int n;
    pthread_t thread_id;
    if (timeout_minute)
        pthread_create(&thread_id, NULL, &tcp_timeout_check, NULL);

    while (1) {
        n = epoll_wait(epollfd, events, MAX_CONNECTION, -1);
        while (n-- > 0) {
            if (events[n].data.fd == server_sock) {
                accept_client();
            } else if (events[n].data.fd == server_sock6) {
                accept_client6();
            } else {
                if (events[n].events & EPOLLIN) {
                    tcp_in((conn *) events[n].data.ptr, configure);
                }
                if (events[n].events & EPOLLOUT) {
                    tcp_out((conn *) events[n].data.ptr);
                }
            }
        }
    }
    close(epollfd);
}

int process_signal(int signal, char *process_name)
{
    char bufer[PATH_SIZE];
    char comm[PATH_SIZE];
    char proc_comm_name[PATH_SIZE];
    int number[PATH_SIZE] = { 0 };
    int n = 0;
    FILE *fp;
    DIR *dir;
    struct dirent *ptr;
    dir = opendir("/proc");
    bzero(bufer, 0);
    bzero(comm, 0);
    bzero(proc_comm_name, 0);
    while ((ptr = readdir(dir)) != NULL) {
        if (ptr->d_type == DT_DIR && strcasecmp(ptr->d_name, ".") && strcasecmp(ptr->d_name, "..")) {
            sprintf(comm, "/proc/%s/comm", ptr->d_name);
            if (access(comm, F_OK) == 0) {
                fp = fopen(comm, "r");
                if (fgets(bufer, PATH_SIZE - 1, fp) == NULL) {
                    fclose(fp);
                    continue;
                }
                sscanf(bufer, "%s", proc_comm_name);
                if (!strcmp(process_name, proc_comm_name)) {
                    number[n] = atoi(ptr->d_name);
                    n += 1;
                }
                fclose(fp);
            }
        }

    }
    closedir(dir);

    if (signal == SERVER_STATUS) { // 状态
        n -= 2;                 // 去除最后一个搜索时的本身进程和最后加一后未使用的
        for (; n >= 0; n--) {   // 依据数组从大到小的下标打印PID
            printf("\t%d\n", number[n]);
        }
    }
    if (signal == SERVER_STOP || signal == SERVER_RELOAD) { // 关闭
        struct passwd *pwent = NULL;
        pwent = getpwnam("root");
        return kill_all(15, 1, &process_name, pwent);
    }

    return 0;
}

int get_executable_path(char *processdir, char *processname, int len)
{
    char *filename;
    if (readlink("/proc/self/exe", processdir, len) <= 0)
        return -1;
    filename = strrchr(processdir, '/');
    if (filename == NULL)
        return -1;
    ++filename;
    strcpy(processname, filename);
    *filename = '\0';
    return (int)(filename - processdir);
}

void server_ini()
{
    signal(SIGPIPE, SIG_IGN);   // 忽略PIPE信号
    if (daemon(1, 1)) {
        perror("daemon");
        return;
    }
    //while (process-- > 1 && fork() == 0);
}

void _main(int argc, char *argv[])
{
    int opt, i;
    char path[PATH_SIZE] = { 0 };
    char executable_filename[PATH_SIZE] = { 0 };
    (void)get_executable_path(path, executable_filename, sizeof(path));
    char *inifile = "/CProxy.conf";
    struct rlimit rt;
    inifile = strcat(path, inifile);
    conf *configure = (struct CONF *)malloc(sizeof(struct CONF));
    memset(configure, 0, sizeof(struct CONF));
    read_conf(inifile, configure);

    sslEncodeCode = 0;          // 默认SSL不转码
    if (configure->sslencoding > 0) // 如果配置文件有sslencoding值,优先使用配置文件读取的值
        sslEncodeCode = configure->sslencoding;
    timeout_minute = 0;         // 默认不超时
    if (configure->timeout > 0) // 如果配置文件有值,优先使用配置文件读取的值
        timeout_minute = configure->timeout;
    process = 2;                // 默认开启2个进程
    if (configure->process > 0) // 如果配置文件有值,优先使用配置文件读取的值
        process = configure->process;

    int longindex = 0;
    char optstring[] = ":l:f:t:p:c:e:s:h?";
    static struct option longopts[] = {
        { "local_address", required_argument, 0, 'l' },
        { "remote_address", required_argument, 0, 'f' },
        { "timeout", required_argument, 0, 't' },
        { "process", required_argument, 0, 'p' },
        { "config", required_argument, 0, 'c' },
        { "coding", required_argument, 0, 'e' },
        { "signal", required_argument, 0, 's' },
        { "help", no_argument, 0, 'h' },
        { "?", no_argument, 0, '?' },
        { 0, 0, 0, 0 }
    };
    char *p = NULL;
    //char optstring[] = ":l:f:t:p:c:e:s:h?";
    //while (-1 != (opt = getopt(argc, argv, optstring))) {
    while (-1 != (opt = getopt_long(argc, argv, optstring, longopts, &longindex))) {
        switch (opt) {
        case 'l':
            p = strchr(optarg, ':');
            if (p) {
                strncpy(local_host, optarg, p - optarg);
                local_port = atoi(p + 1);
            } else {
                strncpy(local_host, optarg, strlen(local_host));
            }
            break;
        case 'f':
            p = strchr(optarg, ':');
            if (p) {
                strncpy(remote_host, optarg, p - optarg);
                remote_port = atoi(p + 1);
            } else {
                strncpy(remote_host, optarg, strlen(remote_host));
            }
            break;
        case 't':
            timeout_minute = (time_t) atoi(optarg); // 如果指定-t,优先使用参数提供的值(输入值 > 配置文件读取的值)
            break;
        case 'p':
            process = atoi(optarg);
            break;
        case 'c':
            free_conf(configure);
            read_conf(optarg, configure);
            break;
        case 'e':
            sslEncodeCode = atoi(optarg);
            break;
        case 's':
            if (strcasecmp(optarg, "stop") == 0 || strcasecmp(optarg, "quit") == 0) {
                free_conf(configure);
                exit(process_signal(SERVER_STOP, executable_filename));
            }
            if (strcasecmp(optarg, "restart") == 0 || strcasecmp(optarg, "reload") == 0) {
                process_signal(SERVER_RELOAD, executable_filename);
            }
            if (strcasecmp(optarg, "status") == 0)
                exit(process_signal(SERVER_STATUS, executable_filename));
            break;
        case 'h':
        case '?':
            help_information();
            exit(0);
            break;
        default:
            ;
        }
    }

    // 设置每个进程允许打开的最大文件数
    rt.rlim_max = rt.rlim_cur = MAX_CONNECTION * 2;
    if (setrlimit(RLIMIT_NOFILE, &rt) == -1) {
        perror("setrlimit");
    }

    server_ini();               // 守护进程
    httpdns_initialize(configure); // 初始化http_dns
    memset(cts, 0, sizeof(cts));
    for (i = MAX_CONNECTION; i--;)
        cts[i].fd = -1;
    // 为服务端的结构体分配内存
    for (i = 1; i < MAX_CONNECTION; i += 2) {
        cts[i].header_buffer = (char *)malloc(BUFFER_SIZE);
        if (cts[i].header_buffer == NULL) {
            fputs("out of memory.", stderr);
            exit(1);
        }
    }
    
    server_sock = create_server_socket(configure->tcp_listen);  // IPV4
    server_sock6 = create_server_socket6(configure->tcp6_listen);// IPV6
    epollfd = epoll_create(MAX_CONNECTION);
    if (epollfd == -1) {
        perror("epoll_create");
        exit(1);
    }
    static struct epoll_event event;
    event.events = EPOLLIN;
    event.data.fd = server_sock;
    if (-1 == epoll_ctl(epollfd, EPOLL_CTL_ADD, server_sock, &event)) {
        exit(1);
    }
    
    event.events = EPOLLIN;
    event.data.fd = server_sock6;
    if (-1 == epoll_ctl(epollfd, EPOLL_CTL_ADD, server_sock6, &event)) {
        exit(1);
    }
    
    if (setegid(configure->uid) == -1 || seteuid(configure->uid) == -1) // 设置uid
        exit(1);

    //start_server(configure); // 单线程
    //httpdns_loop(configure);

    pthread_t thread_id = 0;
    sigset_t signal_mask;
    sigemptyset(&signal_mask);
    sigaddset(&signal_mask, SIGPIPE); // 忽略PIPE信号
    if (pthread_sigmask(SIG_BLOCK, &signal_mask, NULL) != 0) {
        printf("block sigpipe error\n");
    }
    if (timeout_minute)
        pthread_create(&thread_id, NULL, &tcp_timeout_check, NULL);
    if (pthread_create(&thread_id, NULL, &http_proxy_loop, (void *)configure) != 0)
        perror("pthread_create");
    if (pthread_create(&thread_id, NULL, &httpdns_loop, (void *)configure) != 0)
        perror("pthread_create");

    pthread_join(thread_id, NULL);
    pthread_exit(NULL);

/*  线程分离
    pthread_attr_t attr;
    pthread_attr_init(&attr);
    pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
    pthread_create(&thread_id, &attr, &tcp_timeout_check, NULL);
    pthread_create(&thread_id, &attr, &http_proxy_loop, (void *)configure);
    pthread_create(&thread_id, &attr, &httpdns_loop, (void *)configure);
    pthread_exit(NULL);
*/
    return;
}

int main(int argc, char *argv[])
{
    _main(argc, argv);
    return 0;
}