Mercurial > hg > nginx
view src/core/ngx_proxy_protocol.c @ 7145:83600ce25995 stable-1.12
Fixed buffer overread with unix sockets after accept().
Some OSes (notably macOS, NetBSD, and Solaris) allow unix socket addresses
larger than struct sockaddr_un. Moreover, some of them (macOS, Solaris)
return socklen of the socket address before it was truncated to fit the
buffer provided. As such, on these systems socklen must not be used without
additional check that it is within the buffer provided.
Appropriate checks added to ngx_event_accept() (after accept()),
ngx_event_recvmsg() (after recvmsg()), and ngx_set_inherited_sockets()
(after getsockname()).
We also obtain socket addresses via getsockname() in
ngx_connection_local_sockaddr(), but it does not need any checks as
it is only used for INET and INET6 sockets (as there can be no
wildcard unix sockets).
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 04 Oct 2017 21:19:33 +0300 |
parents | b3b7e33083ac |
children | 416953ef0428 |
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/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> u_char * ngx_proxy_protocol_read(ngx_connection_t *c, u_char *buf, u_char *last) { size_t len; u_char ch, *p, *addr, *port; ngx_int_t n; p = buf; len = last - buf; 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; addr = p; for ( ;; ) { if (p == last) { goto invalid; } ch = *p++; if (ch == ' ') { break; } if (ch != ':' && ch != '.' && (ch < 'a' || ch > 'f') && (ch < 'A' || ch > 'F') && (ch < '0' || ch > '9')) { goto invalid; } } len = p - addr - 1; c->proxy_protocol_addr.data = ngx_pnalloc(c->pool, len); if (c->proxy_protocol_addr.data == NULL) { return NULL; } ngx_memcpy(c->proxy_protocol_addr.data, addr, len); c->proxy_protocol_addr.len = len; for ( ;; ) { if (p == last) { goto invalid; } if (*p++ == ' ') { break; } } port = p; for ( ;; ) { if (p == last) { goto invalid; } if (*p++ == ' ') { break; } } len = p - port - 1; n = ngx_atoi(port, len); if (n < 0 || n > 65535) { goto invalid; } c->proxy_protocol_port = (in_port_t) n; ngx_log_debug2(NGX_LOG_DEBUG_CORE, c->log, 0, "PROXY protocol address: %V %i", &c->proxy_protocol_addr, n); 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; } 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); }