Mercurial > hg > nginx
view src/core/ngx_proxy_protocol.c @ 8018:5119c8150478
Fixed runtime handling of systems without EPOLLRDHUP support.
In 7583:efd71d49bde0 (nginx 1.17.5) along with introduction of the
ioctl(FIONREAD) support proper handling of systems without EPOLLRDHUP
support in the kernel (but with EPOLLRDHUP in headers) was broken.
Before the change, rev->available was never set to 0 unless
ngx_use_epoll_rdhup was also set (that is, runtime test for EPOLLRDHUP
introduced in 6536:f7849bfb6d21 succeeded). After the change,
rev->available might reach 0 on systems without runtime EPOLLRDHUP
support, stopping further reading in ngx_readv_chain() and ngx_unix_recv().
And, if EOF happened to be already reported along with the last event,
it is not reported again by epoll_wait(), leading to connection hangs
and timeouts on such systems.
This affects Linux kernels before 2.6.17 if nginx was compiled
with newer headers, and, more importantly, emulation layers, such as
DigitalOcean's App Platform's / gVisor's epoll emulation layer.
Fix is to explicitly check ngx_use_epoll_rdhup before the corresponding
rev->pending_eof tests in ngx_readv_chain() and ngx_unix_recv().
author | Marcus Ball <marcus.ball@live.com> |
---|---|
date | Mon, 30 May 2022 02:38:07 +0300 |
parents | 89adf49fe76a |
children | 017fd847f4f7 |
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/* * 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) ((p)[0] << 8 | (p)[1]) 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; 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); 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: ngx_log_error(NGX_LOG_ERR, c->log, 0, "broken header: \"%*s\"", (size_t) (last - 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) { ngx_log_debug1(NGX_LOG_DEBUG_CORE, c->log, 0, "PROXY protocol v2 %z bytes of tlv ignored", end - buf); } c->proxy_protocol = pp; return end; }