netdata/aclk/aclk_proxy.c

#include "aclk_proxy.h"

#include "daemon/common.h"

#define ACLK_PROXY_ENV "env"
#define ACLK_PROXY_CONFIG_VAR "proxy"

struct {
    ACLK_PROXY_TYPE type;
    const char *url_str;
} supported_proxy_types[] = {
    { .type = PROXY_TYPE_SOCKS5,   .url_str = "socks5"  ACLK_PROXY_PROTO_ADDR_SEPARATOR },
    { .type = PROXY_TYPE_SOCKS5,   .url_str = "socks5h" ACLK_PROXY_PROTO_ADDR_SEPARATOR },
    { .type = PROXY_TYPE_HTTP,     .url_str = "http"    ACLK_PROXY_PROTO_ADDR_SEPARATOR },
    { .type = PROXY_TYPE_UNKNOWN,  .url_str = NULL                                      },
};

static inline ACLK_PROXY_TYPE aclk_find_proxy(const char *string)
{
    int i = 0;
    while (supported_proxy_types[i].url_str) {
        if (!strncmp(supported_proxy_types[i].url_str, string, strlen(supported_proxy_types[i].url_str)))
            return supported_proxy_types[i].type;
        i++;
    }
    return PROXY_TYPE_UNKNOWN;
}

ACLK_PROXY_TYPE aclk_verify_proxy(const char *string)
{
    if (!string)
        return PROXY_TYPE_UNKNOWN;

    while (*string == 0x20)
        string++;

    if (!*string)
        return PROXY_TYPE_UNKNOWN;

    return aclk_find_proxy(string);
}

// helper function to censor user&password
// for logging purposes
void safe_log_proxy_censor(char *proxy)
{
    size_t length = strlen(proxy);
    char *auth = proxy + length - 1;
    char *cur;

    while ((auth >= proxy) && (*auth != '@'))
        auth--;

    //if not found or @ is first char do nothing
    if (auth <= proxy)
        return;

    cur = strstr(proxy, ACLK_PROXY_PROTO_ADDR_SEPARATOR);
    if (!cur)
        cur = proxy;
    else
        cur += strlen(ACLK_PROXY_PROTO_ADDR_SEPARATOR);

    while (cur < auth) {
        *cur = 'X';
        cur++;
    }
}

static inline void safe_log_proxy_error(char *str, const char *proxy)
{
    char *log = strdupz(proxy);
    safe_log_proxy_censor(log);
    netdata_log_error("%s Provided Value:\"%s\"", str, log);
    freez(log);
}

static inline int check_socks_enviroment(const char **proxy)
{
    char *tmp = getenv("socks_proxy");

    if (!tmp)
        return 1;

    if (aclk_verify_proxy(tmp) == PROXY_TYPE_SOCKS5) {
        *proxy = tmp;
        return 0;
    }

    safe_log_proxy_error(
        "Environment var \"socks_proxy\" defined but of unknown format. Supported syntax: \"socks5[h]://[user:pass@]host:ip\".",
        tmp);
    return 1;
}

static inline int check_http_enviroment(const char **proxy)
{
    char *tmp = getenv("http_proxy");

    if (!tmp)
        return 1;

    if (aclk_verify_proxy(tmp) == PROXY_TYPE_HTTP) {
        *proxy = tmp;
        return 0;
    }

    safe_log_proxy_error(
        "Environment var \"http_proxy\" defined but of unknown format. Supported syntax: \"http[s]://[user:pass@]host:ip\".",
        tmp);
    return 1;
}

const char *aclk_lws_wss_get_proxy_setting(ACLK_PROXY_TYPE *type)
{
    const char *proxy = config_get(CONFIG_SECTION_CLOUD, ACLK_PROXY_CONFIG_VAR, ACLK_PROXY_ENV);
    *type = PROXY_DISABLED;

    if (strcmp(proxy, "none") == 0)
        return proxy;

    if (strcmp(proxy, ACLK_PROXY_ENV) == 0) {
        if (check_socks_enviroment(&proxy) == 0) {
#ifdef LWS_WITH_SOCKS5
            *type = PROXY_TYPE_SOCKS5;
            return proxy;
#else
            safe_log_proxy_error("socks_proxy environment variable set to use SOCKS5 proxy "
                "but Libwebsockets used doesn't have SOCKS5 support built in. "
                "Ignoring and checking for other options.",
                proxy);
#endif
        }
        if (check_http_enviroment(&proxy) == 0)
            *type = PROXY_TYPE_HTTP;
        return proxy;
    }

    *type = aclk_verify_proxy(proxy);
#ifndef LWS_WITH_SOCKS5
    if (*type == PROXY_TYPE_SOCKS5) {
        safe_log_proxy_error(
            "Config var \"" ACLK_PROXY_CONFIG_VAR
            "\" set to use SOCKS5 proxy but Libwebsockets used is built without support for SOCKS proxy. ACLK will be disabled.",
            proxy);
    }
#endif
    if (*type == PROXY_TYPE_UNKNOWN) {
        *type = PROXY_DISABLED;
        safe_log_proxy_error(
            "Config var \"" ACLK_PROXY_CONFIG_VAR
            "\" defined but of unknown format. Supported syntax: \"socks5[h]://[user:pass@]host:ip\".",
            proxy);
    }

    return proxy;
}

// helper function to read settings only once (static)
// as claiming, challenge/response and ACLK
// read the same thing, no need to parse again
const char *aclk_get_proxy(ACLK_PROXY_TYPE *type)
{
    static const char *proxy = NULL;
    static ACLK_PROXY_TYPE proxy_type = PROXY_NOT_SET;

    if (proxy_type == PROXY_NOT_SET)
        proxy = aclk_lws_wss_get_proxy_setting(&proxy_type);

    *type = proxy_type;
    return proxy;
}