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-rw-r--r--erts/epmd/src/epmd_srv.c270
1 files changed, 101 insertions, 169 deletions
diff --git a/erts/epmd/src/epmd_srv.c b/erts/epmd/src/epmd_srv.c
index a033fab244..3499ab2934 100644
--- a/erts/epmd/src/epmd_srv.c
+++ b/erts/epmd/src/epmd_srv.c
@@ -2,7 +2,7 @@
/*
* %CopyrightBegin%
*
- * Copyright Ericsson AB 1998-2010. All Rights Reserved.
+ * Copyright Ericsson AB 1998-2011. All Rights Reserved.
*
* The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
@@ -39,46 +39,16 @@
* server keeps the socket open where the request for registration was
* made.
*
- * The protocol is briefly documented in "erl_ext_dist.txt". All requests
- * to this server are done with a packet
+ * The protocol is briefly documented in the ERTS User's Guide, see
+ * http://www.erlang.org/doc/apps/erts/erl_dist_protocol.html
+ *
+ * All requests to this server are done with a packet
*
* 2 n
* +--------+---------+
* | Length | Request |
* +--------+---------+
*
- * In all but one case there is only one request for each connection made
- * to this server so we can safely close the socket after sending the
- * reply. The exception is ALIVE_REQ where we keep the connection
- * open without sending any data. When we receive a "close" this is
- * an indication that the Erlang node was terminated. The termination
- * may have been "normal" or caused by a crash. The operating system
- * ensure that the connection is closed either way.
- *
- * Reading is done non-blocking, i.e. we call a "read" only if we are
- * told by the "select" function that there are data to read.
- *
- * Two databases are used: One node database where the registered names
- * of the nodes are stored, and one connection database where the state
- * of sockets and the data buffers is stored.
- *
- * Incomplete packets are thrown away after a timout. The Erlang node
- * doing the request is responsible for completing in it in a reasonable time.
- *
- * Note that if the server gets busy it may not have time to
- * process all requests for connection. The "accept()" function
- * will on most operating systems silently refuse to accept more
- * than 5 outstanding requests. It is the client's responsibility
- * to retry the request a number of times with random time interval.
- * The "-debug" flag will insert a delay so you can test this
- * behaviour.
- *
- * FIXME: In this code we assume that the packets we send on each
- * socket is so small that a "write()" never block
- *
- * FIXME: We never restarts a read or write that was terminated
- * by an interrupt. Do we need to?
- *
*/
/* We use separate data structures for node names and connections
@@ -98,7 +68,6 @@ static int conn_open(EpmdVars*,int);
static int conn_close_fd(EpmdVars*,int);
static void node_init(EpmdVars*);
-static Node *node_reg(EpmdVars*,char*,int,int);
static Node *node_reg2(EpmdVars*,char*, int, int, unsigned char, unsigned char, int, int, int, char*);
static int node_unreg(EpmdVars*,char*);
static int node_unreg_sock(EpmdVars*,int);
@@ -138,7 +107,7 @@ void run(EpmdVars *g)
* because addresses will be reused even if they are still in use.
*/
-#if (!defined(__WIN32__) && !defined(_OSE_))
+#if !defined(__WIN32__)
/* We ignore the SIGPIPE signal that is raised when we call write
twice on a socket closed by the other end. */
signal(SIGPIPE, SIG_IGN);
@@ -156,10 +125,6 @@ void run(EpmdVars *g)
accept function is called. We set the listen socket
to be non blocking to prevent us from being hanging
in accept() waiting for the next request. */
-#ifdef _OSE_
- opt = 1;
- if (ioctl(listensock, FIONBIO, (char*)&opt) != 0)
-#else
#if (defined(__WIN32__) || defined(NO_FCNTL))
opt = 1;
if (ioctl(listensock, FIONBIO, &opt) != 0) /* Gives warning in VxWorks */
@@ -167,7 +132,6 @@ void run(EpmdVars *g)
opt = fcntl(listensock, F_GETFL, 0);
if (fcntl(listensock, F_SETFL, opt | O_NONBLOCK) == -1)
#endif /* __WIN32__ || VXWORKS */
-#endif /* _OSE_ */
dbg_perror(g,"failed to set non-blocking mode of listening socket %d",
listensock);
@@ -176,18 +140,6 @@ void run(EpmdVars *g)
SET_ADDR_ANY(iserv_addr, FAMILY, sport);
}
-#ifdef _OSE_
- {
- int optlen = sizeof(opt);
- opt = 1;
- if(getsockopt(listensock, SOL_SOCKET, SO_REUSEADDR,
- (void*)&opt, &optlen) < 0)
- fprintf(stderr, "\n\nGETSOCKOPT FAILS! %d\n\n", errno);
- else if(opt == 1)
- fprintf(stderr, "SO_REUSEADDR is set!\n");
- }
-#endif
-
if(bind(listensock,(struct sockaddr*) &iserv_addr, sizeof(iserv_addr)) < 0 )
{
if (errno == EADDRINUSE)
@@ -205,8 +157,10 @@ void run(EpmdVars *g)
dbg_printf(g,2,"starting");
- listen(listensock, SOMAXCONN);
-
+ if(listen(listensock, SOMAXCONN) < 0) {
+ dbg_perror(g,"failed to listen on socket");
+ epmd_cleanup_exit(g,1);
+ }
FD_ZERO(&g->orig_read_mask);
FD_SET(listensock,&g->orig_read_mask);
@@ -227,8 +181,16 @@ void run(EpmdVars *g)
timeout.tv_sec = (g->packet_timeout < IDLE_TIMEOUT) ? 1 : IDLE_TIMEOUT;
timeout.tv_usec = 0;
- if ((ret = select(g->max_conn,&read_mask,(fd_set *)0,(fd_set *)0,&timeout)) < 0)
+ if ((ret = select(g->max_conn,&read_mask,(fd_set *)0,(fd_set *)0,&timeout)) < 0) {
dbg_perror(g,"error in select ");
+ switch (errno) {
+ case EAGAIN:
+ case EINTR:
+ break;
+ default:
+ epmd_cleanup_exit(g,1);
+ }
+ }
else {
time_t now;
if (ret == 0) {
@@ -312,11 +274,9 @@ static void do_read(EpmdVars *g,Connection *s)
s->fd,val);
dbg_print_buf(g,s->buf,val);
- /* FIXME: Shouldn't be needed to close down.... */
node_unreg_sock(g,s->fd);
epmd_conn_close(g,s);
}
- /* FIXME: We always close, probably the right thing to do */
return;
}
@@ -401,12 +361,21 @@ static int do_accept(EpmdVars *g,int listensock)
if (msgsock < 0) {
dbg_perror(g,"error in accept");
- return EPMD_FALSE;
+ switch (errno) {
+ case EAGAIN:
+ case ECONNABORTED:
+ case EINTR:
+ return EPMD_FALSE;
+ default:
+ epmd_cleanup_exit(g,1);
+ }
}
return conn_open(g,msgsock);
}
+/* buf is actually one byte larger than bsize,
+ giving place for null termination */
static void do_request(g, fd, s, buf, bsize)
EpmdVars *g;
int fd;
@@ -417,117 +386,23 @@ static void do_request(g, fd, s, buf, bsize)
char wbuf[OUTBUF_SIZE]; /* Buffer for writing */
int i;
- /*
- * Terminate packet as a C string. Needed for requests received from Erlang
- * nodes with lower version than R3A.
- */
-
- buf[bsize] = '\0';
+ buf[bsize] = '\0'; /* Needed for strcmp in PORT2 and STOP requests
+ buf is always large enough */
switch (*buf)
{
- case EPMD_ALIVE_REQ:
- dbg_printf(g,1,"** got ALIVE_REQ");
-
- /* The packet has the format "axxyyyyyy" where xx is port, given
- in network byte order, and yyyyyy is symname, possibly null
- terminated. */
-
- if (buf[bsize - 1] == '\000') /* Skip null termination */
- bsize--;
-
- if (bsize <= 3)
- {
- dbg_printf(g,0,"packet to small for request ALIVE_REQ (%d)", bsize);
- return;
- }
-
- for (i = 3; i < bsize; i++)
- if (buf[i] == '\000')
- {
- dbg_printf(g,0,"node name contains ascii 0 in ALIVE_REQ");
- return;
- }
-
- {
- Node *node;
- int eport;
- char *name = &buf[3]; /* points to node name */
-
- eport = get_int16(&buf[1]);
-
- if ((node = node_reg(g, name, fd, eport)) == NULL)
- return;
-
- wbuf[0] = EPMD_ALIVE_OK_RESP;
- put_int16(node->creation, wbuf+1);
-
- if (g->delay_write) /* Test of busy server */
- sleep(g->delay_write);
-
- if (reply(g, fd, wbuf, 3) != 3)
- {
- dbg_tty_printf(g,1,"failed to send ALIVE_OK_RESP for \"%s\"",name);
- return;
- }
-
- dbg_tty_printf(g,1,"** sent ALIVE_OK_RESP for \"%s\"",name);
- s->keep = EPMD_TRUE; /* Don't close on inactivity */
- }
- break;
-
- case EPMD_PORT_REQ:
- dbg_printf(g,1,"** got PORT_REQ");
-
- if (buf[bsize - 1] == '\000') /* Skip null termination */
- bsize--;
-
- if (bsize <= 1)
- {
- dbg_printf(g,0,"packet to small for request PORT_REQ (%d)", bsize);
- return;
- }
-
- for (i = 1; i < bsize; i++)
- if (buf[i] == '\000')
- {
- dbg_printf(g,0,"node name contains ascii 0 in PORT_REQ");
- return;
- }
-
- {
- char *name = &buf[1]; /* Points to node name */
- Node *node;
-
- for (node = g->nodes.reg; node; node = node->next)
- {
- if (strcmp(node->symname, name) == 0)
- {
- put_int16(node->port,wbuf);
- if (reply(g, fd, wbuf, 2) != 2)
- {
- dbg_tty_printf(g,1,"failed to send PORT_RESP for %s: %d",
- name,node->port);
- return;
- }
- dbg_tty_printf(g,1,"** sent PORT_RESP for %s: %d",
- name,node->port);
- return;
- }
- }
- dbg_tty_printf(g,1,"Closed on PORT_REQ for %s",name);
- }
- /* FIXME: How about an answer if no port? Is a close enough? */
- break;
-
case EPMD_ALIVE2_REQ:
dbg_printf(g,1,"** got ALIVE2_REQ");
+ if (!s->local_peer) {
+ dbg_printf(g,0,"ALIVE2_REQ from non local address");
+ return;
+ }
/* The packet has the format "axxyyyyyy" where xx is port, given
in network byte order, and yyyyyy is symname, possibly null
terminated. */
- if (bsize <= 13)
+ if (bsize <= 13) /* at least one character for the node name */
{
dbg_printf(g,0,"packet to small for request ALIVE2_REQ (%d)",bsize);
return;
@@ -550,7 +425,17 @@ static void do_request(g, fd, s, buf, bsize)
highvsn = get_int16(&buf[5]);
lowvsn = get_int16(&buf[7]);
namelen = get_int16(&buf[9]);
+ if (namelen + 13 > bsize) {
+ dbg_printf(g,0,"Node name size error in ALIVE2_REQ");
+ return;
+ }
extralen = get_int16(&buf[11+namelen]);
+
+ if (extralen + namelen + 13 > bsize) {
+ dbg_printf(g,0,"Extra info size error in ALIVE2_REQ");
+ return;
+ }
+
for (i = 11 ; i < 11 + namelen; i ++)
if (buf[i] == '\000') {
dbg_printf(g,0,"node name contains ascii 0 in ALIVE2_REQ");
@@ -593,7 +478,7 @@ static void do_request(g, fd, s, buf, bsize)
if (bsize <= 1)
{
- dbg_printf(g,0,"packet to small for request PORT2_REQ (%d)", bsize);
+ dbg_printf(g,0,"packet too small for request PORT2_REQ (%d)", bsize);
return;
}
@@ -681,6 +566,10 @@ static void do_request(g, fd, s, buf, bsize)
case EPMD_DUMP_REQ:
dbg_printf(g,1,"** got DUMP_REQ");
+ if (!s->local_peer) {
+ dbg_printf(g,0,"DUMP_REQ from non local address");
+ return;
+ }
{
Node *node;
@@ -730,7 +619,19 @@ static void do_request(g, fd, s, buf, bsize)
break;
case EPMD_KILL_REQ:
+ if (!s->local_peer) {
+ dbg_printf(g,0,"KILL_REQ from non local address");
+ return;
+ }
dbg_printf(g,1,"** got KILL_REQ");
+
+ if (!g->brutal_kill && (g->nodes.reg != NULL)) {
+ dbg_printf(g,0,"Disallowed KILL_REQ, live nodes");
+ if (reply(g, fd,"NO",2) != 2)
+ dbg_printf(g,0,"failed to send reply to KILL_REQ");
+ return;
+ }
+
if (reply(g, fd,"OK",2) != 2)
dbg_printf(g,0,"failed to send reply to KILL_REQ");
dbg_tty_printf(g,1,"epmd killed");
@@ -740,9 +641,18 @@ static void do_request(g, fd, s, buf, bsize)
case EPMD_STOP_REQ:
dbg_printf(g,1,"** got STOP_REQ");
+ if (!s->local_peer) {
+ dbg_printf(g,0,"STOP_REQ from non local address");
+ return;
+ }
+ if (!g->brutal_kill) {
+ dbg_printf(g,0,"Disallowed STOP_REQ, no relaxed_command_check");
+ return;
+ }
+
if (bsize <= 1 )
{
- dbg_printf(g,0,"packet to small for request STOP_REQ (%d)",bsize);
+ dbg_printf(g,0,"packet too small for request STOP_REQ (%d)",bsize);
return;
}
@@ -827,6 +737,14 @@ static int conn_open(EpmdVars *g,int fd)
for (i = 0; i < g->max_conn; i++) {
if (g->conn[i].open == EPMD_FALSE) {
+ struct sockaddr_in si;
+#ifdef HAVE_SOCKLEN_T
+ socklen_t st;
+#else
+ int st;
+#endif
+ st = sizeof(si);
+
g->active_conn++;
s = &g->conn[i];
@@ -836,6 +754,20 @@ static int conn_open(EpmdVars *g,int fd)
s->fd = fd;
s->open = EPMD_TRUE;
s->keep = EPMD_FALSE;
+
+ /* Determine if connection is from localhost */
+ if (getpeername(s->fd,(struct sockaddr*) &si,&st) ||
+ st < sizeof(si)) {
+ /* Failure to get peername is regarder as non local host */
+ s->local_peer = EPMD_FALSE;
+ } else {
+ s->local_peer =
+ ((((unsigned) ntohl(si.sin_addr.s_addr)) & 0xFF000000U) ==
+ 0x7F000000U); /* Only 127.x.x.x allowed, no false positives */
+ }
+ dbg_tty_printf(g,2,(s->local_peer) ? "Local peer connected" :
+ "Non-local peer connected");
+
s->want = 0; /* Currently unknown */
s->got = 0;
s->mod_time = current_time(g); /* Note activity */
@@ -904,7 +836,7 @@ static void node_init(EpmdVars *g)
/* We have got a close on a connection and it may be a
- EPMD_ALIVE_CLOSE_REQ. Note that this call shouild be called
+ EPMD_ALIVE_CLOSE_REQ. Note that this call should be called
*before* calling conn_close() */
static int node_unreg(EpmdVars *g,char *name)
@@ -992,11 +924,6 @@ static int node_unreg_sock(EpmdVars *g,int fd)
* Perhaps use the oldest or something.
*/
-static Node *node_reg(EpmdVars *g,char *name,int fd, int port)
-{
- return node_reg2(g, name, fd, port, 0, 0, 0, 0, 0, NULL);
-}
-
static Node *node_reg2(EpmdVars *g,
char* name,
int fd,
@@ -1022,6 +949,11 @@ static Node *node_reg2(EpmdVars *g,
dbg_printf(g,0,"node name is too long (%d) %s", strlen(name), name);
return NULL;
}
+ if (extralen > MAXSYMLEN)
+ {
+ dbg_printf(g,0,"extra data is too long (%d) %s", strlen(name), name);
+ return NULL;
+ }
/* Fail if it is already registered */