view src/core/ngx_proxy_protocol.c @ 8078:5244d3b165ff

SSL: single allocation in session cache on 32-bit platforms. Given the present typical SSL session sizes, on 32-bit platforms it is now beneficial to store all data in a single allocation, since rbtree node + session id + ASN1 representation of a session takes 256 bytes of shared memory (36 + 32 + 150 = about 218 bytes plus SNI server name). Storing all data in a single allocation is beneficial for SNI names up to about 40 characters long and makes it possible to store about 4000 sessions in one megabyte (instead of about 3000 sessions now). This also slightly simplifies the code.
author Maxim Dounin <mdounin@mdounin.ru>
date Wed, 12 Oct 2022 20:14:40 +0300
parents aa663cc2a77d
children 17d6a537fb1b
line wrap: on
line source


/*
 * Copyright (C) Roman Arutyunyan
 * Copyright (C) Nginx, Inc.
 */


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


#define NGX_PROXY_PROTOCOL_AF_INET          1
#define NGX_PROXY_PROTOCOL_AF_INET6         2


#define ngx_proxy_protocol_parse_uint16(p)                                    \
    ( ((uint16_t) (p)[0] << 8)                                                \
    + (           (p)[1]) )

#define ngx_proxy_protocol_parse_uint32(p)                                    \
    ( ((uint32_t) (p)[0] << 24)                                               \
    + (           (p)[1] << 16)                                               \
    + (           (p)[2] << 8)                                                \
    + (           (p)[3]) )


typedef struct {
    u_char                                  signature[12];
    u_char                                  version_command;
    u_char                                  family_transport;
    u_char                                  len[2];
} ngx_proxy_protocol_header_t;


typedef struct {
    u_char                                  src_addr[4];
    u_char                                  dst_addr[4];
    u_char                                  src_port[2];
    u_char                                  dst_port[2];
} ngx_proxy_protocol_inet_addrs_t;


typedef struct {
    u_char                                  src_addr[16];
    u_char                                  dst_addr[16];
    u_char                                  src_port[2];
    u_char                                  dst_port[2];
} ngx_proxy_protocol_inet6_addrs_t;


typedef struct {
    u_char                                  type;
    u_char                                  len[2];
} ngx_proxy_protocol_tlv_t;


typedef struct {
    u_char                                  client;
    u_char                                  verify[4];
} ngx_proxy_protocol_tlv_ssl_t;


typedef struct {
    ngx_str_t                               name;
    ngx_uint_t                              type;
} ngx_proxy_protocol_tlv_entry_t;


static u_char *ngx_proxy_protocol_read_addr(ngx_connection_t *c, u_char *p,
    u_char *last, ngx_str_t *addr);
static u_char *ngx_proxy_protocol_read_port(u_char *p, u_char *last,
    in_port_t *port, u_char sep);
static u_char *ngx_proxy_protocol_v2_read(ngx_connection_t *c, u_char *buf,
    u_char *last);
static ngx_int_t ngx_proxy_protocol_lookup_tlv(ngx_connection_t *c,
    ngx_str_t *tlvs, ngx_uint_t type, ngx_str_t *value);


static ngx_proxy_protocol_tlv_entry_t  ngx_proxy_protocol_tlv_entries[] = {
    { ngx_string("alpn"),       0x01 },
    { ngx_string("authority"),  0x02 },
    { ngx_string("unique_id"),  0x05 },
    { ngx_string("ssl"),        0x20 },
    { ngx_string("netns"),      0x30 },
    { ngx_null_string,          0x00 }
};


static ngx_proxy_protocol_tlv_entry_t  ngx_proxy_protocol_tlv_ssl_entries[] = {
    { ngx_string("version"),    0x21 },
    { ngx_string("cn"),         0x22 },
    { ngx_string("cipher"),     0x23 },
    { ngx_string("sig_alg"),    0x24 },
    { ngx_string("key_alg"),    0x25 },
    { ngx_null_string,          0x00 }
};


u_char *
ngx_proxy_protocol_read(ngx_connection_t *c, u_char *buf, u_char *last)
{
    size_t                 len;
    u_char                *p;
    ngx_proxy_protocol_t  *pp;

    static const u_char signature[] = "\r\n\r\n\0\r\nQUIT\n";

    p = buf;
    len = last - buf;

    if (len >= sizeof(ngx_proxy_protocol_header_t)
        && memcmp(p, signature, sizeof(signature) - 1) == 0)
    {
        return ngx_proxy_protocol_v2_read(c, buf, last);
    }

    if (len < 8 || ngx_strncmp(p, "PROXY ", 6) != 0) {
        goto invalid;
    }

    p += 6;
    len -= 6;

    if (len >= 7 && ngx_strncmp(p, "UNKNOWN", 7) == 0) {
        ngx_log_debug0(NGX_LOG_DEBUG_CORE, c->log, 0,
                       "PROXY protocol unknown protocol");
        p += 7;
        goto skip;
    }

    if (len < 5 || ngx_strncmp(p, "TCP", 3) != 0
        || (p[3] != '4' && p[3] != '6') || p[4] != ' ')
    {
        goto invalid;
    }

    p += 5;

    pp = ngx_pcalloc(c->pool, sizeof(ngx_proxy_protocol_t));
    if (pp == NULL) {
        return NULL;
    }

    p = ngx_proxy_protocol_read_addr(c, p, last, &pp->src_addr);
    if (p == NULL) {
        goto invalid;
    }

    p = ngx_proxy_protocol_read_addr(c, p, last, &pp->dst_addr);
    if (p == NULL) {
        goto invalid;
    }

    p = ngx_proxy_protocol_read_port(p, last, &pp->src_port, ' ');
    if (p == NULL) {
        goto invalid;
    }

    p = ngx_proxy_protocol_read_port(p, last, &pp->dst_port, CR);
    if (p == NULL) {
        goto invalid;
    }

    if (p == last) {
        goto invalid;
    }

    if (*p++ != LF) {
        goto invalid;
    }

    ngx_log_debug4(NGX_LOG_DEBUG_CORE, c->log, 0,
                   "PROXY protocol src: %V %d, dst: %V %d",
                   &pp->src_addr, pp->src_port, &pp->dst_addr, pp->dst_port);

    c->proxy_protocol = pp;

    return p;

skip:

    for ( /* void */ ; p < last - 1; p++) {
        if (p[0] == CR && p[1] == LF) {
            return p + 2;
        }
    }

invalid:

    for (p = buf; p < last; p++) {
        if (*p == CR || *p == LF) {
            break;
        }
    }

    ngx_log_error(NGX_LOG_ERR, c->log, 0,
                  "broken header: \"%*s\"", (size_t) (p - buf), buf);

    return NULL;
}


static u_char *
ngx_proxy_protocol_read_addr(ngx_connection_t *c, u_char *p, u_char *last,
    ngx_str_t *addr)
{
    size_t  len;
    u_char  ch, *pos;

    pos = p;

    for ( ;; ) {
        if (p == last) {
            return NULL;
        }

        ch = *p++;

        if (ch == ' ') {
            break;
        }

        if (ch != ':' && ch != '.'
            && (ch < 'a' || ch > 'f')
            && (ch < 'A' || ch > 'F')
            && (ch < '0' || ch > '9'))
        {
            return NULL;
        }
    }

    len = p - pos - 1;

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

    ngx_memcpy(addr->data, pos, len);
    addr->len = len;

    return p;
}


static u_char *
ngx_proxy_protocol_read_port(u_char *p, u_char *last, in_port_t *port,
    u_char sep)
{
    size_t      len;
    u_char     *pos;
    ngx_int_t   n;

    pos = p;

    for ( ;; ) {
        if (p == last) {
            return NULL;
        }

        if (*p++ == sep) {
            break;
        }
    }

    len = p - pos - 1;

    n = ngx_atoi(pos, len);
    if (n < 0 || n > 65535) {
        return NULL;
    }

    *port = (in_port_t) n;

    return p;
}


u_char *
ngx_proxy_protocol_write(ngx_connection_t *c, u_char *buf, u_char *last)
{
    ngx_uint_t  port, lport;

    if (last - buf < NGX_PROXY_PROTOCOL_MAX_HEADER) {
        return NULL;
    }

    if (ngx_connection_local_sockaddr(c, NULL, 0) != NGX_OK) {
        return NULL;
    }

    switch (c->sockaddr->sa_family) {

    case AF_INET:
        buf = ngx_cpymem(buf, "PROXY TCP4 ", sizeof("PROXY TCP4 ") - 1);
        break;

#if (NGX_HAVE_INET6)
    case AF_INET6:
        buf = ngx_cpymem(buf, "PROXY TCP6 ", sizeof("PROXY TCP6 ") - 1);
        break;
#endif

    default:
        return ngx_cpymem(buf, "PROXY UNKNOWN" CRLF,
                          sizeof("PROXY UNKNOWN" CRLF) - 1);
    }

    buf += ngx_sock_ntop(c->sockaddr, c->socklen, buf, last - buf, 0);

    *buf++ = ' ';

    buf += ngx_sock_ntop(c->local_sockaddr, c->local_socklen, buf, last - buf,
                         0);

    port = ngx_inet_get_port(c->sockaddr);
    lport = ngx_inet_get_port(c->local_sockaddr);

    return ngx_slprintf(buf, last, " %ui %ui" CRLF, port, lport);
}


static u_char *
ngx_proxy_protocol_v2_read(ngx_connection_t *c, u_char *buf, u_char *last)
{
    u_char                             *end;
    size_t                              len;
    socklen_t                           socklen;
    ngx_uint_t                          version, command, family, transport;
    ngx_sockaddr_t                      src_sockaddr, dst_sockaddr;
    ngx_proxy_protocol_t               *pp;
    ngx_proxy_protocol_header_t        *header;
    ngx_proxy_protocol_inet_addrs_t    *in;
#if (NGX_HAVE_INET6)
    ngx_proxy_protocol_inet6_addrs_t   *in6;
#endif

    header = (ngx_proxy_protocol_header_t *) buf;

    buf += sizeof(ngx_proxy_protocol_header_t);

    version = header->version_command >> 4;

    if (version != 2) {
        ngx_log_error(NGX_LOG_ERR, c->log, 0,
                      "unknown PROXY protocol version: %ui", version);
        return NULL;
    }

    len = ngx_proxy_protocol_parse_uint16(header->len);

    if ((size_t) (last - buf) < len) {
        ngx_log_error(NGX_LOG_ERR, c->log, 0, "header is too large");
        return NULL;
    }

    end = buf + len;

    command = header->version_command & 0x0f;

    /* only PROXY is supported */
    if (command != 1) {
        ngx_log_debug1(NGX_LOG_DEBUG_CORE, c->log, 0,
                       "PROXY protocol v2 unsupported command %ui", command);
        return end;
    }

    transport = header->family_transport & 0x0f;

    /* only STREAM is supported */
    if (transport != 1) {
        ngx_log_debug1(NGX_LOG_DEBUG_CORE, c->log, 0,
                       "PROXY protocol v2 unsupported transport %ui",
                       transport);
        return end;
    }

    pp = ngx_pcalloc(c->pool, sizeof(ngx_proxy_protocol_t));
    if (pp == NULL) {
        return NULL;
    }

    family = header->family_transport >> 4;

    switch (family) {

    case NGX_PROXY_PROTOCOL_AF_INET:

        if ((size_t) (end - buf) < sizeof(ngx_proxy_protocol_inet_addrs_t)) {
            return NULL;
        }

        in = (ngx_proxy_protocol_inet_addrs_t *) buf;

        src_sockaddr.sockaddr_in.sin_family = AF_INET;
        src_sockaddr.sockaddr_in.sin_port = 0;
        memcpy(&src_sockaddr.sockaddr_in.sin_addr, in->src_addr, 4);

        dst_sockaddr.sockaddr_in.sin_family = AF_INET;
        dst_sockaddr.sockaddr_in.sin_port = 0;
        memcpy(&dst_sockaddr.sockaddr_in.sin_addr, in->dst_addr, 4);

        pp->src_port = ngx_proxy_protocol_parse_uint16(in->src_port);
        pp->dst_port = ngx_proxy_protocol_parse_uint16(in->dst_port);

        socklen = sizeof(struct sockaddr_in);

        buf += sizeof(ngx_proxy_protocol_inet_addrs_t);

        break;

#if (NGX_HAVE_INET6)

    case NGX_PROXY_PROTOCOL_AF_INET6:

        if ((size_t) (end - buf) < sizeof(ngx_proxy_protocol_inet6_addrs_t)) {
            return NULL;
        }

        in6 = (ngx_proxy_protocol_inet6_addrs_t *) buf;

        src_sockaddr.sockaddr_in6.sin6_family = AF_INET6;
        src_sockaddr.sockaddr_in6.sin6_port = 0;
        memcpy(&src_sockaddr.sockaddr_in6.sin6_addr, in6->src_addr, 16);

        dst_sockaddr.sockaddr_in6.sin6_family = AF_INET6;
        dst_sockaddr.sockaddr_in6.sin6_port = 0;
        memcpy(&dst_sockaddr.sockaddr_in6.sin6_addr, in6->dst_addr, 16);

        pp->src_port = ngx_proxy_protocol_parse_uint16(in6->src_port);
        pp->dst_port = ngx_proxy_protocol_parse_uint16(in6->dst_port);

        socklen = sizeof(struct sockaddr_in6);

        buf += sizeof(ngx_proxy_protocol_inet6_addrs_t);

        break;

#endif

    default:
        ngx_log_debug1(NGX_LOG_DEBUG_CORE, c->log, 0,
                       "PROXY protocol v2 unsupported address family %ui",
                       family);
        return end;
    }

    pp->src_addr.data = ngx_pnalloc(c->pool, NGX_SOCKADDR_STRLEN);
    if (pp->src_addr.data == NULL) {
        return NULL;
    }

    pp->src_addr.len = ngx_sock_ntop(&src_sockaddr.sockaddr, socklen,
                                     pp->src_addr.data, NGX_SOCKADDR_STRLEN, 0);

    pp->dst_addr.data = ngx_pnalloc(c->pool, NGX_SOCKADDR_STRLEN);
    if (pp->dst_addr.data == NULL) {
        return NULL;
    }

    pp->dst_addr.len = ngx_sock_ntop(&dst_sockaddr.sockaddr, socklen,
                                     pp->dst_addr.data, NGX_SOCKADDR_STRLEN, 0);

    ngx_log_debug4(NGX_LOG_DEBUG_CORE, c->log, 0,
                   "PROXY protocol v2 src: %V %d, dst: %V %d",
                   &pp->src_addr, pp->src_port, &pp->dst_addr, pp->dst_port);

    if (buf < end) {
        pp->tlvs.data = ngx_pnalloc(c->pool, end - buf);
        if (pp->tlvs.data == NULL) {
            return NULL;
        }

        ngx_memcpy(pp->tlvs.data, buf, end - buf);
        pp->tlvs.len = end - buf;
    }

    c->proxy_protocol = pp;

    return end;
}


ngx_int_t
ngx_proxy_protocol_get_tlv(ngx_connection_t *c, ngx_str_t *name,
    ngx_str_t *value)
{
    u_char                          *p;
    size_t                           n;
    uint32_t                         verify;
    ngx_str_t                        ssl, *tlvs;
    ngx_int_t                        rc, type;
    ngx_proxy_protocol_tlv_ssl_t    *tlv_ssl;
    ngx_proxy_protocol_tlv_entry_t  *te;

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

    ngx_log_debug1(NGX_LOG_DEBUG_CORE, c->log, 0,
                   "PROXY protocol v2 get tlv \"%V\"", name);

    te = ngx_proxy_protocol_tlv_entries;
    tlvs = &c->proxy_protocol->tlvs;

    p = name->data;
    n = name->len;

    if (n >= 4 && p[0] == 's' && p[1] == 's' && p[2] == 'l' && p[3] == '_') {

        rc = ngx_proxy_protocol_lookup_tlv(c, tlvs, 0x20, &ssl);
        if (rc != NGX_OK) {
            return rc;
        }

        if (ssl.len < sizeof(ngx_proxy_protocol_tlv_ssl_t)) {
            return NGX_ERROR;
        }

        p += 4;
        n -= 4;

        if (n == 6 && ngx_strncmp(p, "verify", 6) == 0) {

            tlv_ssl = (ngx_proxy_protocol_tlv_ssl_t *) ssl.data;
            verify = ngx_proxy_protocol_parse_uint32(tlv_ssl->verify);

            value->data = ngx_pnalloc(c->pool, NGX_INT32_LEN);
            if (value->data == NULL) {
                return NGX_ERROR;
            }

            value->len = ngx_sprintf(value->data, "%uD", verify)
                         - value->data;
            return NGX_OK;
        }

        ssl.data += sizeof(ngx_proxy_protocol_tlv_ssl_t);
        ssl.len -= sizeof(ngx_proxy_protocol_tlv_ssl_t);

        te = ngx_proxy_protocol_tlv_ssl_entries;
        tlvs = &ssl;
    }

    if (n >= 2 && p[0] == '0' && p[1] == 'x') {

        type = ngx_hextoi(p + 2, n - 2);
        if (type == NGX_ERROR) {
            ngx_log_error(NGX_LOG_ERR, c->log, 0,
                          "invalid PROXY protocol TLV \"%V\"", name);
            return NGX_ERROR;
        }

        return ngx_proxy_protocol_lookup_tlv(c, tlvs, type, value);
    }

    for ( /* void */ ; te->type; te++) {
        if (te->name.len == n && ngx_strncmp(te->name.data, p, n) == 0) {
            return ngx_proxy_protocol_lookup_tlv(c, tlvs, te->type, value);
        }
    }

    ngx_log_error(NGX_LOG_ERR, c->log, 0,
                  "unknown PROXY protocol TLV \"%V\"", name);

    return NGX_DECLINED;
}


static ngx_int_t
ngx_proxy_protocol_lookup_tlv(ngx_connection_t *c, ngx_str_t *tlvs,
    ngx_uint_t type, ngx_str_t *value)
{
    u_char                    *p;
    size_t                     n, len;
    ngx_proxy_protocol_tlv_t  *tlv;

    ngx_log_debug1(NGX_LOG_DEBUG_CORE, c->log, 0,
                   "PROXY protocol v2 lookup tlv:%02xi", type);

    p = tlvs->data;
    n = tlvs->len;

    while (n) {
        if (n < sizeof(ngx_proxy_protocol_tlv_t)) {
            ngx_log_error(NGX_LOG_ERR, c->log, 0, "broken PROXY protocol TLV");
            return NGX_ERROR;
        }

        tlv = (ngx_proxy_protocol_tlv_t *) p;
        len = ngx_proxy_protocol_parse_uint16(tlv->len);

        p += sizeof(ngx_proxy_protocol_tlv_t);
        n -= sizeof(ngx_proxy_protocol_tlv_t);

        if (n < len) {
            ngx_log_error(NGX_LOG_ERR, c->log, 0, "broken PROXY protocol TLV");
            return NGX_ERROR;
        }

        if (tlv->type == type) {
            value->data = p;
            value->len = len;
            return NGX_OK;
        }

        p += len;
        n -= len;
    }

    return NGX_DECLINED;
}