// SPDX-License-Identifier: GPL-3.0-or-later

#ifndef NETDATA_WEB_CLIENT_H
#define NETDATA_WEB_CLIENT_H 1

#include "libnetdata/libnetdata.h"

#ifdef NETDATA_WITH_ZLIB
extern int web_enable_gzip, web_gzip_level, web_gzip_strategy;
#endif /* NETDATA_WITH_ZLIB */

// HTTP_CODES 2XX Success
#define HTTP_RESP_OK 200

// HTTP_CODES 3XX Redirections
#define HTTP_RESP_MOVED_PERM 301
#define HTTP_RESP_REDIR_TEMP 307
#define HTTP_RESP_REDIR_PERM 308

// HTTP_CODES 4XX Client Errors
#define HTTP_RESP_BAD_REQUEST 400
#define HTTP_RESP_FORBIDDEN 403
#define HTTP_RESP_NOT_FOUND 404
#define HTTP_RESP_PRECOND_FAIL 412

// HTTP_CODES 5XX Server Errors
#define HTTP_RESP_INTERNAL_SERVER_ERROR 500
#define HTTP_RESP_BACKEND_FETCH_FAILED 503
#define HTTP_RESP_GATEWAY_TIMEOUT 504
#define HTTP_RESP_BACKEND_RESPONSE_INVALID 591

extern int respect_web_browser_do_not_track_policy;
extern char *web_x_frame_options;

typedef enum web_client_mode {
    WEB_CLIENT_MODE_NORMAL = 0,
    WEB_CLIENT_MODE_FILECOPY = 1,
    WEB_CLIENT_MODE_OPTIONS = 2,
    WEB_CLIENT_MODE_STREAM = 3
} WEB_CLIENT_MODE;

typedef enum {
    HTTP_VALIDATION_OK,
    HTTP_VALIDATION_NOT_SUPPORTED,
    HTTP_VALIDATION_MALFORMED_URL,
#ifdef ENABLE_HTTPS
    HTTP_VALIDATION_INCOMPLETE,
    HTTP_VALIDATION_REDIRECT
#else
    HTTP_VALIDATION_INCOMPLETE
#endif
} HTTP_VALIDATION;

typedef enum web_client_flags {
    WEB_CLIENT_FLAG_DEAD = 1 << 1, // if set, this client is dead

    WEB_CLIENT_FLAG_KEEPALIVE = 1 << 2, // if set, the web client will be re-used

    WEB_CLIENT_FLAG_WAIT_RECEIVE = 1 << 3, // if set, we are waiting more input data
    WEB_CLIENT_FLAG_WAIT_SEND = 1 << 4,    // if set, we have data to send to the client

    WEB_CLIENT_FLAG_DO_NOT_TRACK = 1 << 5,      // if set, we should not set cookies on this client
    WEB_CLIENT_FLAG_TRACKING_REQUIRED = 1 << 6, // if set, we need to send cookies

    WEB_CLIENT_FLAG_TCP_CLIENT = 1 << 7,  // if set, the client is using a TCP socket
    WEB_CLIENT_FLAG_UNIX_CLIENT = 1 << 8, // if set, the client is using a UNIX socket

    WEB_CLIENT_FLAG_DONT_CLOSE_SOCKET = 1 << 9, // don't close the socket when cleaning up (static-threaded web server)

    WEB_CLIENT_CHUNKED_TRANSFER = 1 << 10, // chunked transfer (used with zlib compression)
} WEB_CLIENT_FLAGS;

#define web_client_flag_check(w, flag) ((w)->flags & (flag))
#define web_client_flag_set(w, flag) (w)->flags |= flag
#define web_client_flag_clear(w, flag) (w)->flags &= ~flag

#define WEB_CLIENT_IS_DEAD(w) web_client_flag_set(w, WEB_CLIENT_FLAG_DEAD)
#define web_client_check_dead(w) web_client_flag_check(w, WEB_CLIENT_FLAG_DEAD)

#define web_client_has_keepalive(w) web_client_flag_check(w, WEB_CLIENT_FLAG_KEEPALIVE)
#define web_client_enable_keepalive(w) web_client_flag_set(w, WEB_CLIENT_FLAG_KEEPALIVE)
#define web_client_disable_keepalive(w) web_client_flag_clear(w, WEB_CLIENT_FLAG_KEEPALIVE)

#define web_client_has_donottrack(w) web_client_flag_check(w, WEB_CLIENT_FLAG_DO_NOT_TRACK)
#define web_client_enable_donottrack(w) web_client_flag_set(w, WEB_CLIENT_FLAG_DO_NOT_TRACK)
#define web_client_disable_donottrack(w) web_client_flag_clear(w, WEB_CLIENT_FLAG_DO_NOT_TRACK)

#define web_client_has_tracking_required(w) web_client_flag_check(w, WEB_CLIENT_FLAG_TRACKING_REQUIRED)
#define web_client_enable_tracking_required(w) web_client_flag_set(w, WEB_CLIENT_FLAG_TRACKING_REQUIRED)
#define web_client_disable_tracking_required(w) web_client_flag_clear(w, WEB_CLIENT_FLAG_TRACKING_REQUIRED)

#define web_client_has_wait_receive(w) web_client_flag_check(w, WEB_CLIENT_FLAG_WAIT_RECEIVE)
#define web_client_enable_wait_receive(w) web_client_flag_set(w, WEB_CLIENT_FLAG_WAIT_RECEIVE)
#define web_client_disable_wait_receive(w) web_client_flag_clear(w, WEB_CLIENT_FLAG_WAIT_RECEIVE)

#define web_client_has_wait_send(w) web_client_flag_check(w, WEB_CLIENT_FLAG_WAIT_SEND)
#define web_client_enable_wait_send(w) web_client_flag_set(w, WEB_CLIENT_FLAG_WAIT_SEND)
#define web_client_disable_wait_send(w) web_client_flag_clear(w, WEB_CLIENT_FLAG_WAIT_SEND)

#define web_client_set_tcp(w) web_client_flag_set(w, WEB_CLIENT_FLAG_TCP_CLIENT)
#define web_client_set_unix(w) web_client_flag_set(w, WEB_CLIENT_FLAG_UNIX_CLIENT)
#define web_client_check_unix(w) web_client_flag_check(w, WEB_CLIENT_FLAG_UNIX_CLIENT)
#define web_client_check_tcp(w) web_client_flag_check(w, WEB_CLIENT_FLAG_TCP_CLIENT)

#define web_client_is_corkable(w) web_client_flag_check(w, WEB_CLIENT_FLAG_TCP_CLIENT)

#define NETDATA_WEB_REQUEST_URL_SIZE 8192
#define NETDATA_WEB_RESPONSE_ZLIB_CHUNK_SIZE 16384
#define NETDATA_WEB_RESPONSE_HEADER_SIZE 4096
#define NETDATA_WEB_REQUEST_COOKIE_SIZE 1024
#define NETDATA_WEB_REQUEST_ORIGIN_HEADER_SIZE 1024
#define NETDATA_WEB_RESPONSE_INITIAL_SIZE 16384
#define NETDATA_WEB_REQUEST_RECEIVE_SIZE 16384
#define NETDATA_WEB_REQUEST_MAX_SIZE 16384

struct response {
    BUFFER *header;        // our response header
    BUFFER *header_output; // internal use
    BUFFER *data;          // our response data buffer

    int code; // the HTTP response code

    size_t rlen; // if non-zero, the excepted size of ifd (input of firecopy)
    size_t sent; // current data length sent to output

    int zoutput; // if set to 1, web_client_send() will send compressed data
#ifdef NETDATA_WITH_ZLIB
    z_stream zstream;                                    // zlib stream for sending compressed output to client
    Bytef zbuffer[NETDATA_WEB_RESPONSE_ZLIB_CHUNK_SIZE]; // temporary buffer for storing compressed output
    size_t zsent;                                        // the compressed bytes we have sent to the client
    size_t zhave;                                        // the compressed bytes that we have received from zlib
    unsigned int zinitialized : 1;
#endif /* NETDATA_WITH_ZLIB */
};

struct web_client {
    unsigned long long id;

    WEB_CLIENT_FLAGS flags;  // status flags for the client
    WEB_CLIENT_MODE mode;    // the operational mode of the client
    WEB_CLIENT_ACL acl;      // the access list of the client
    int port_acl;            // the operations permitted on the port the client connected to
    char *auth_bearer_token; // the Bearer auth token (if sent)
    size_t header_parse_tries;
    size_t header_parse_last_size;

    int tcp_cork; // 1 = we have a cork on the socket

    int ifd;
    int ofd;

    char client_ip[INET6_ADDRSTRLEN]; // Defined buffer sizes include null-terminators
    char client_port[NI_MAXSERV];
    char server_host[NI_MAXHOST];
    char client_host[NI_MAXHOST];
    char forwarded_host[NI_MAXHOST]; //Used with proxy

    char decoded_url[NETDATA_WEB_REQUEST_URL_SIZE + 1];          // we decode the URL in this buffer
    char decoded_query_string[NETDATA_WEB_REQUEST_URL_SIZE + 1]; // we decode the Query String in this buffer
    char last_url[NETDATA_WEB_REQUEST_URL_SIZE + 1];             // we keep a copy of the decoded URL here
    size_t url_path_length;
    char separator;        // This value can be either '?' or 'f'
    char *url_search_path; //A pointer to the search path sent by the client

    struct timeval tv_in, tv_ready;

    char cookie1[NETDATA_WEB_REQUEST_COOKIE_SIZE + 1];
    char cookie2[NETDATA_WEB_REQUEST_COOKIE_SIZE + 1];
    char origin[NETDATA_WEB_REQUEST_ORIGIN_HEADER_SIZE + 1];
    char *user_agent;

    struct response response;

    size_t stats_received_bytes;
    size_t stats_sent_bytes;

    // cache of web_client allocations
    struct web_client *prev; // maintain a linked list of web clients
    struct web_client *next; // for the web servers that need it

    // MULTI-THREADED WEB SERVER MEMBERS
    netdata_thread_t thread; // the thread servicing this client
    volatile int running;    // 1 when the thread runs, 0 otherwise

    // STATIC-THREADED WEB SERVER MEMBERS
    size_t pollinfo_slot;          // POLLINFO slot of the web client
    size_t pollinfo_filecopy_slot; // POLLINFO slot of the file read
#ifdef ENABLE_HTTPS
    struct netdata_ssl ssl;
#endif
};

int web_client_permission_denied(struct web_client *w);

ssize_t web_client_send(struct web_client *w);
ssize_t web_client_receive(struct web_client *w);
ssize_t web_client_read_file(struct web_client *w);

void web_client_process_request(struct web_client *w);
void web_client_request_done(struct web_client *w);

void buffer_data_options2string(BUFFER *wb, uint32_t options);

int mysendfile(struct web_client *w, char *filename);

void web_client_build_http_header(struct web_client *w);
char *strip_control_characters(char *url);

#include "daemon/common.h"

#endif
