Mercurial > hg > nginx-quic
view src/core/ngx_proxy_protocol.c @ 7629:f47f7d3d1bfa
Mp4: fixed possible chunk offset overflow.
In "co64" atom chunk start offset is a 64-bit unsigned integer. When trimming
the "mdat" atom, chunk offsets are casted to off_t values which are typically
64-bit signed integers. A specially crafted mp4 file with huge chunk offsets
may lead to off_t overflow and result in negative trim boundaries.
The consequences of the overflow are:
- Incorrect Content-Length header value in the response.
- Negative left boundary of the response file buffer holding the trimmed "mdat".
This leads to pread()/sendfile() errors followed by closing the client
connection.
On rare systems where off_t is a 32-bit integer, this scenario is also feasible
with the "stco" atom.
The fix is to add checks which make sure data chunks referenced by each track
are within the mp4 file boundaries. Additionally a few more checks are added to
ensure mp4 file consistency and log errors.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Wed, 26 Feb 2020 15:10:46 +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; }