view src/stream/ngx_stream_realip_module.c @ 7732:59e1c73fe02b

SSL: ssl_reject_handshake directive (ticket #195). In some cases it might be needed to reject SSL handshake based on SNI server name provided, for example, to make sure an invalid certificate is not returned to clients trying to contact a name-based virtual server without SSL configured. Previously, a "ssl_ciphers aNULL;" was used for this. This workaround, however, is not compatible with TLSv1.3, in particular, when using BoringSSL, where it is not possible to configure TLSv1.3 ciphers at all. With this change, the ssl_reject_handshake directive is introduced, which instructs nginx to reject SSL handshakes with an "unrecognized_name" alert in a particular server block. For example, to reject handshake with names other than example.com, one can use the following configuration: server { listen 443 ssl; ssl_reject_handshake on; } server { listen 443 ssl; server_name example.com; ssl_certificate example.com.crt; ssl_certificate_key example.com.key; } The following configuration can be used to reject all SSL handshakes without SNI server name provided: server { listen 443 ssl; ssl_reject_handshake on; } server { listen 443 ssl; server_name ~^; ssl_certificate example.crt; ssl_certificate_key example.key; } Additionally, the ssl_reject_handshake directive makes configuring certificates for the default server block optional. If no certificates are configured in the default server for a given listening socket, certificates must be defined in all non-default server blocks with the listening socket in question.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 22 Oct 2020 18:02:28 +0300
parents 06b01840bd42
children
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_stream.h>


typedef struct {
    ngx_array_t       *from;     /* array of ngx_cidr_t */
} ngx_stream_realip_srv_conf_t;


typedef struct {
    struct sockaddr   *sockaddr;
    socklen_t          socklen;
    ngx_str_t          addr_text;
} ngx_stream_realip_ctx_t;


static ngx_int_t ngx_stream_realip_handler(ngx_stream_session_t *s);
static ngx_int_t ngx_stream_realip_set_addr(ngx_stream_session_t *s,
    ngx_addr_t *addr);
static char *ngx_stream_realip_from(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static void *ngx_stream_realip_create_srv_conf(ngx_conf_t *cf);
static char *ngx_stream_realip_merge_srv_conf(ngx_conf_t *cf, void *parent,
    void *child);
static ngx_int_t ngx_stream_realip_add_variables(ngx_conf_t *cf);
static ngx_int_t ngx_stream_realip_init(ngx_conf_t *cf);


static ngx_int_t ngx_stream_realip_remote_addr_variable(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_realip_remote_port_variable(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);


static ngx_command_t  ngx_stream_realip_commands[] = {

    { ngx_string("set_real_ip_from"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_stream_realip_from,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


static ngx_stream_module_t  ngx_stream_realip_module_ctx = {
    ngx_stream_realip_add_variables,       /* preconfiguration */
    ngx_stream_realip_init,                /* postconfiguration */

    NULL,                                  /* create main configuration */
    NULL,                                  /* init main configuration */

    ngx_stream_realip_create_srv_conf,     /* create server configuration */
    ngx_stream_realip_merge_srv_conf       /* merge server configuration */
};


ngx_module_t  ngx_stream_realip_module = {
    NGX_MODULE_V1,
    &ngx_stream_realip_module_ctx,         /* module context */
    ngx_stream_realip_commands,            /* module directives */
    NGX_STREAM_MODULE,                     /* module type */
    NULL,                                  /* init master */
    NULL,                                  /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


static ngx_stream_variable_t  ngx_stream_realip_vars[] = {

    { ngx_string("realip_remote_addr"), NULL,
      ngx_stream_realip_remote_addr_variable, 0, 0, 0 },

    { ngx_string("realip_remote_port"), NULL,
      ngx_stream_realip_remote_port_variable, 0, 0, 0 },

      ngx_stream_null_variable
};


static ngx_int_t
ngx_stream_realip_handler(ngx_stream_session_t *s)
{
    ngx_addr_t                     addr;
    ngx_connection_t              *c;
    ngx_stream_realip_srv_conf_t  *rscf;

    rscf = ngx_stream_get_module_srv_conf(s, ngx_stream_realip_module);

    if (rscf->from == NULL) {
        return NGX_DECLINED;
    }

    c = s->connection;

    if (c->proxy_protocol == NULL) {
        return NGX_DECLINED;
    }

    if (ngx_cidr_match(c->sockaddr, rscf->from) != NGX_OK) {
        return NGX_DECLINED;
    }

    if (ngx_parse_addr(c->pool, &addr, c->proxy_protocol->src_addr.data,
                       c->proxy_protocol->src_addr.len)
        != NGX_OK)
    {
        return NGX_DECLINED;
    }

    ngx_inet_set_port(addr.sockaddr, c->proxy_protocol->src_port);

    return ngx_stream_realip_set_addr(s, &addr);
}


static ngx_int_t
ngx_stream_realip_set_addr(ngx_stream_session_t *s, ngx_addr_t *addr)
{
    size_t                    len;
    u_char                   *p;
    u_char                    text[NGX_SOCKADDR_STRLEN];
    ngx_connection_t         *c;
    ngx_stream_realip_ctx_t  *ctx;

    c = s->connection;

    ctx = ngx_palloc(c->pool, sizeof(ngx_stream_realip_ctx_t));
    if (ctx == NULL) {
        return NGX_ERROR;
    }

    len = ngx_sock_ntop(addr->sockaddr, addr->socklen, text,
                        NGX_SOCKADDR_STRLEN, 0);
    if (len == 0) {
        return NGX_ERROR;
    }

    p = ngx_pnalloc(c->pool, len);
    if (p == NULL) {
        return NGX_ERROR;
    }

    ngx_memcpy(p, text, len);

    ngx_stream_set_ctx(s, ctx, ngx_stream_realip_module);

    ctx->sockaddr = c->sockaddr;
    ctx->socklen = c->socklen;
    ctx->addr_text = c->addr_text;

    c->sockaddr = addr->sockaddr;
    c->socklen = addr->socklen;
    c->addr_text.len = len;
    c->addr_text.data = p;

    return NGX_DECLINED;
}


static char *
ngx_stream_realip_from(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_realip_srv_conf_t *rscf = conf;

    ngx_int_t             rc;
    ngx_str_t            *value;
    ngx_url_t             u;
    ngx_cidr_t            c, *cidr;
    ngx_uint_t            i;
    struct sockaddr_in   *sin;
#if (NGX_HAVE_INET6)
    struct sockaddr_in6  *sin6;
#endif

    value = cf->args->elts;

    if (rscf->from == NULL) {
        rscf->from = ngx_array_create(cf->pool, 2,
                                      sizeof(ngx_cidr_t));
        if (rscf->from == NULL) {
            return NGX_CONF_ERROR;
        }
    }

#if (NGX_HAVE_UNIX_DOMAIN)

    if (ngx_strcmp(value[1].data, "unix:") == 0) {
        cidr = ngx_array_push(rscf->from);
        if (cidr == NULL) {
            return NGX_CONF_ERROR;
        }

        cidr->family = AF_UNIX;
        return NGX_CONF_OK;
    }

#endif

    rc = ngx_ptocidr(&value[1], &c);

    if (rc != NGX_ERROR) {
        if (rc == NGX_DONE) {
            ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                               "low address bits of %V are meaningless",
                               &value[1]);
        }

        cidr = ngx_array_push(rscf->from);
        if (cidr == NULL) {
            return NGX_CONF_ERROR;
        }

        *cidr = c;

        return NGX_CONF_OK;
    }

    ngx_memzero(&u, sizeof(ngx_url_t));
    u.host = value[1];

    if (ngx_inet_resolve_host(cf->pool, &u) != NGX_OK) {
        if (u.err) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "%s in set_real_ip_from \"%V\"",
                               u.err, &u.host);
        }

        return NGX_CONF_ERROR;
    }

    cidr = ngx_array_push_n(rscf->from, u.naddrs);
    if (cidr == NULL) {
        return NGX_CONF_ERROR;
    }

    ngx_memzero(cidr, u.naddrs * sizeof(ngx_cidr_t));

    for (i = 0; i < u.naddrs; i++) {
        cidr[i].family = u.addrs[i].sockaddr->sa_family;

        switch (cidr[i].family) {

#if (NGX_HAVE_INET6)
        case AF_INET6:
            sin6 = (struct sockaddr_in6 *) u.addrs[i].sockaddr;
            cidr[i].u.in6.addr = sin6->sin6_addr;
            ngx_memset(cidr[i].u.in6.mask.s6_addr, 0xff, 16);
            break;
#endif

        default: /* AF_INET */
            sin = (struct sockaddr_in *) u.addrs[i].sockaddr;
            cidr[i].u.in.addr = sin->sin_addr.s_addr;
            cidr[i].u.in.mask = 0xffffffff;
            break;
        }
    }

    return NGX_CONF_OK;
}


static void *
ngx_stream_realip_create_srv_conf(ngx_conf_t *cf)
{
    ngx_stream_realip_srv_conf_t  *conf;

    conf = ngx_pcalloc(cf->pool, sizeof(ngx_stream_realip_srv_conf_t));
    if (conf == NULL) {
        return NULL;
    }

    /*
     * set by ngx_pcalloc():
     *
     *     conf->from = NULL;
     */

    return conf;
}


static char *
ngx_stream_realip_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
{
    ngx_stream_realip_srv_conf_t *prev = parent;
    ngx_stream_realip_srv_conf_t *conf = child;

    if (conf->from == NULL) {
        conf->from = prev->from;
    }

    return NGX_CONF_OK;
}


static ngx_int_t
ngx_stream_realip_add_variables(ngx_conf_t *cf)
{
    ngx_stream_variable_t  *var, *v;

    for (v = ngx_stream_realip_vars; v->name.len; v++) {
        var = ngx_stream_add_variable(cf, &v->name, v->flags);
        if (var == NULL) {
            return NGX_ERROR;
        }

        var->get_handler = v->get_handler;
        var->data = v->data;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_stream_realip_init(ngx_conf_t *cf)
{
    ngx_stream_handler_pt        *h;
    ngx_stream_core_main_conf_t  *cmcf;

    cmcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_core_module);

    h = ngx_array_push(&cmcf->phases[NGX_STREAM_POST_ACCEPT_PHASE].handlers);
    if (h == NULL) {
        return NGX_ERROR;
    }

    *h = ngx_stream_realip_handler;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_realip_remote_addr_variable(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    ngx_str_t                *addr_text;
    ngx_stream_realip_ctx_t  *ctx;

    ctx = ngx_stream_get_module_ctx(s, ngx_stream_realip_module);

    addr_text = ctx ? &ctx->addr_text : &s->connection->addr_text;

    v->len = addr_text->len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = addr_text->data;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_realip_remote_port_variable(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    ngx_uint_t                port;
    struct sockaddr          *sa;
    ngx_stream_realip_ctx_t  *ctx;

    ctx = ngx_stream_get_module_ctx(s, ngx_stream_realip_module);

    sa = ctx ? ctx->sockaddr : s->connection->sockaddr;

    v->len = 0;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    v->data = ngx_pnalloc(s->connection->pool, sizeof("65535") - 1);
    if (v->data == NULL) {
        return NGX_ERROR;
    }

    port = ngx_inet_get_port(sa);

    if (port > 0 && port < 65536) {
        v->len = ngx_sprintf(v->data, "%ui", port) - v->data;
    }

    return NGX_OK;
}