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bugfix: wrong source address for the replying packet when received ud…
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…p packet via req.socket on secondary address. (#233)
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@zhuizhuhaomeng
zhuizhuhaomeng authored Mar 29, 2021
1 parent e9cfdc0 commit 149d82e
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Showing 4 changed files with 216 additions and 3 deletions.
4 changes: 3 additions & 1 deletion .travis.yml
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Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@ compiler:

addons:
apt:
packages: [ axel, cpanminus, libgd-dev, libtest-base-perl, libtext-diff-perl, liburi-perl, libwww-perl, libtest-longstring-perl, liblist-moreutils-perl ]
packages: [ axel, cpanminus, libgd-dev, libtest-base-perl, libtext-diff-perl, liburi-perl, libwww-perl, libtest-longstring-perl, liblist-moreutils-perl, dnsutils ]

cache:
apt: true
Expand Down Expand Up @@ -67,6 +67,8 @@ script:
- sudo iptables -I OUTPUT 1 -p udp --dport 10086 -j REJECT
- sudo iptables -A OUTPUT -p tcp --dst 127.0.0.2 --dport 12345 -j DROP
- sudo iptables -A OUTPUT -p udp --dst 127.0.0.2 --dport 12345 -j DROP
- sudo ip addr add 10.254.254.1/24 dev lo
- sudo ip addr add 10.254.254.2/24 dev lo
- tar zxf download-cache/pcre-$PCRE_VER.tar.gz
- cd pcre-$PCRE_VER/
- ./configure --prefix=$PCRE_PREFIX --enable-jit --enable-utf --enable-unicode-properties > build.log 2>&1 || (cat build.log && exit 1)
Expand Down
153 changes: 151 additions & 2 deletions src/ngx_stream_lua_socket_udp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -71,6 +71,8 @@ static int ngx_stream_lua_socket_udp_close(lua_State *L);
static ngx_int_t ngx_stream_lua_socket_udp_resume(ngx_stream_lua_request_t *r);
static void ngx_stream_lua_udp_resolve_cleanup(void *data);
static void ngx_stream_lua_udp_socket_cleanup(void *data);
static ssize_t ngx_stream_lua_udp_sendmsg(ngx_connection_t *c,
ngx_iovec_t *vec);


enum {
Expand Down Expand Up @@ -786,6 +788,8 @@ ngx_stream_lua_socket_udp_send(lua_State *L)
int type;
const char *msg;
ngx_str_t query;
ngx_iovec_t vec;
struct iovec iovs[1];

ngx_stream_lua_socket_udp_upstream_t *u;
ngx_stream_lua_loc_conf_t *llcf;
Expand Down Expand Up @@ -921,9 +925,16 @@ ngx_stream_lua_socket_udp_send(lua_State *L)

dd("sending query %.*s", (int) query.len, query.data);

n = ngx_udp_send(u->udp_connection.connection, query.data, query.len);
vec.iovs = iovs;
vec.nalloc = 1;
vec.count = 1;
iovs[0].iov_base = query.data;
iovs[0].iov_len = query.len;
vec.size = query.len;
n = ngx_stream_lua_udp_sendmsg(u->udp_connection.connection, &vec);

dd("ngx_udp_send returns %d (query len %d)", (int) n, (int) query.len);
dd("ngx_stream_lua_udp_sendmsg returns %d (query len %d)",
(int) n, (int) query.len);

if (n == NGX_ERROR || n == NGX_AGAIN) {
u->socket_errno = ngx_socket_errno;
Expand Down Expand Up @@ -1797,4 +1808,142 @@ ngx_stream_lua_req_socket_udp(lua_State *L)
}


static ssize_t
ngx_stream_lua_udp_sendmsg(ngx_connection_t *c, ngx_iovec_t *vec)
{
ssize_t n;
ngx_err_t err;
struct msghdr msg;

#if (NGX_HAVE_MSGHDR_MSG_CONTROL)

#if (NGX_HAVE_IP_SENDSRCADDR)
u_char msg_control[CMSG_SPACE(sizeof(struct in_addr))];
#elif (NGX_HAVE_IP_PKTINFO)
u_char msg_control[CMSG_SPACE(sizeof(struct in_pktinfo))];
#endif

#if (NGX_HAVE_INET6 && NGX_HAVE_IPV6_RECVPKTINFO)
u_char msg_control6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
#endif

#endif

ngx_memzero(&msg, sizeof(struct msghdr));

if (c->socklen) {
msg.msg_name = c->sockaddr;
msg.msg_namelen = c->socklen;
}

msg.msg_iov = vec->iovs;
msg.msg_iovlen = vec->count;

#if (NGX_HAVE_MSGHDR_MSG_CONTROL)

if (c->listening && c->listening->wildcard && c->local_sockaddr) {

#if (NGX_HAVE_IP_SENDSRCADDR)

if (c->local_sockaddr->sa_family == AF_INET) {
struct cmsghdr *cmsg;
struct in_addr *addr;
struct sockaddr_in *sin;

msg.msg_control = &msg_control;
msg.msg_controllen = sizeof(msg_control);

cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = IPPROTO_IP;
cmsg->cmsg_type = IP_SENDSRCADDR;
cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_addr));

sin = (struct sockaddr_in *) c->local_sockaddr;

addr = (struct in_addr *) CMSG_DATA(cmsg);
*addr = sin->sin_addr;
}

#elif (NGX_HAVE_IP_PKTINFO)

if (c->local_sockaddr->sa_family == AF_INET) {
struct cmsghdr *cmsg;
struct in_pktinfo *pkt;
struct sockaddr_in *sin;

msg.msg_control = &msg_control;
msg.msg_controllen = sizeof(msg_control);

cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = IPPROTO_IP;
cmsg->cmsg_type = IP_PKTINFO;
cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));

sin = (struct sockaddr_in *) c->local_sockaddr;

pkt = (struct in_pktinfo *) CMSG_DATA(cmsg);
ngx_memzero(pkt, sizeof(struct in_pktinfo));
pkt->ipi_spec_dst = sin->sin_addr;
}

#endif

#if (NGX_HAVE_INET6 && NGX_HAVE_IPV6_RECVPKTINFO)

if (c->local_sockaddr->sa_family == AF_INET6) {
struct cmsghdr *cmsg;
struct in6_pktinfo *pkt6;
struct sockaddr_in6 *sin6;

msg.msg_control = &msg_control6;
msg.msg_controllen = sizeof(msg_control6);

cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = IPPROTO_IPV6;
cmsg->cmsg_type = IPV6_PKTINFO;
cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));

sin6 = (struct sockaddr_in6 *) c->local_sockaddr;

pkt6 = (struct in6_pktinfo *) CMSG_DATA(cmsg);
ngx_memzero(pkt6, sizeof(struct in6_pktinfo));
pkt6->ipi6_addr = sin6->sin6_addr;
}

#endif
}

#endif

eintr:

n = sendmsg(c->fd, &msg, 0);

ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0,
"sendto: fd:%d %z of %uz to \"%V\"",
c->fd, n, vec->size, &c->addr_text);
if (n == -1) {
err = ngx_errno;

switch (err) {
case NGX_EAGAIN:
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
"sendmsg() not ready");
return NGX_AGAIN;

case NGX_EINTR:
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
"sendmsg() was interrupted");
goto eintr;

default:
c->write->error = 1;
ngx_connection_error(c, err, "sendmsg() failed");
return NGX_ERROR;
}
}

return n;
}

/* vi:set ft=c ts=4 sw=4 et fdm=marker: */
40 changes: 40 additions & 0 deletions t/142-req-udp-socket.t
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Original file line number Diff line number Diff line change
Expand Up @@ -243,3 +243,43 @@ hello world! my
received: hello world! my
--- no_error_log
[error]



=== TEST 7: request on secondary ip address
sudo ip addr add 10.254.254.1/24 dev lo
sudo ip addr add 10.254.254.2/24 dev lo
nmap will be blocked by travis , use dig to send dns request.
--- dgram_server_config
content_by_lua_block {
local sock, err = ngx.req.socket()
if not sock then
ngx.log(ngx.ERR,"ngx.req.socket error : ", err)
return ngx.exit(ngx.ERROR)
end

local data = sock:receive()
local ok, err = sock:send(data)
if not ok then
ngx.log(ngx.ERR, "failed to send: ", err)
return ngx.exit(ngx.ERROR)
end
}
--- config
location = /dns {
content_by_lua_block {
local cmd = "dig -b 10.254.254.1 @10.254.254.2 www.baidu.com -p " .. tostring(ngx.var.server_port + 1)
local f = io.popen(cmd, "r")
ngx.sleep(0.2)
local result = f:read("*a")
f:close()
ngx.say("hello")
}
}
--- request
GET /dns
--- response_body
hello
--- grep_error_log eval: qr/sendto: fd.*$/
--- grep_error_log_out eval
qr/sendto: fd:\d+ \d+ of \d+ to "10.254.254.1"/
22 changes: 22 additions & 0 deletions valgrind.suppress
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Original file line number Diff line number Diff line change
Expand Up @@ -196,3 +196,25 @@
fun:ngx_set_environment
fun:ngx_single_process_cycle
}
{
<insert_a_suppression_name_here>
Memcheck:Param
sendmsg(msg.msg_control)
fun:sendmsg
fun:ngx_stream_lua_udp_sendmsg
fun:ngx_stream_lua_socket_udp_send
fun:lj_BC_FUNCC
fun:ngx_stream_lua_run_thread
fun:ngx_stream_lua_content_by_chunk
fun:ngx_stream_lua_content_handler_inline
fun:ngx_stream_lua_content_handler
fun:ngx_stream_core_content_phase
fun:ngx_stream_core_run_phases
fun:ngx_stream_session_handler
fun:ngx_stream_init_connection
fun:ngx_event_recvmsg
fun:ngx_epoll_process_events
fun:ngx_process_events_and_timers
fun:ngx_single_process_cycle
fun:main
}

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