Github user SolidWallOfCode commented on a diff in the pull request:
https://github.com/apache/trafficserver/pull/843#discussion_r75874123
--- Diff: plugins/experimental/carp/Common.cc ---
@@ -0,0 +1,364 @@
+
+/** @file
+
+ Loads the CARP configuration
+
+ @section license License
+
+ Licensed to the Apache Software Foundation (ASF) under one
+ or more contributor license agreements. See the NOTICE file
+ distributed with this work for additional information
+ regarding copyright ownership. The ASF licenses this file
+ to you under the Apache License, Version 2.0 (the
+ "License"); you may not use this file except in compliance
+ with the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+#include "Common.h"
+
+#include <arpa/inet.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <netdb.h>
+#include <string.h>
+#include <memory.h>
+
+using namespace std;
+
+/************************************************************************/
+void stringExplode(string str, string separator, vector<string>* results)
+{
+ size_t found;
+ found = str.find_first_of(separator);
+ while (found != std::string::npos)
+ {
+ if (found > 0)
+ {
+ results->push_back(str.substr(0, found));
+ }
+ str = str.substr(found + 1);
+ found = str.find_first_of(separator);
+ }
+ if (str.length() > 0)
+ {
+ results->push_back(str);
+ }
+}
+
+/************************************************************************/
+/*
+ Parse /proc/{pid}/net/tcp
+ sl local_address rem_address st tx_queue rx_queue tr tm->when
retrnsmt uid timeout inode
+ 0: 00000000:036B 00000000:0000 0A 00000000:00000000 00:00000000
00000000 0 0 22272 1 ffff8801b7ecb700 299 0 0 2 -1
+ 1: 00000000:08AE 00000000:0000 0A 00000000:00000000 00:00000000
00000000 0 0 10621 1 ffff8801b7b9a080 299 0 0 2 -1
+ 2: 00000000:006F 00000000:0000 0A 00000000:00000000 00:00000000
00000000 0 0 22046 1 ffff8801b7b9b400 299 0 0 2 -1
+ Parse /proc/{pid}/net/tcp6
+ * sl local_address remote_address
st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode
+ 0: 00000000000000000000000000000000:08AE
00000000000000000000000000000000:0000 0A 00000000:00000000 00:00000000 00000000
0 0 10619 1 ffff8801b266d780 299 0 0 2 -1
+ 1: 00000000000000000000000000000000:006F
00000000000000000000000000000000:0000 0A 00000000:00000000 00:00000000 00000000
0 0 22051 1 ffff8801b3a51880 299 0 0 2 -1
+ 2: 00000000000000000000000000000000:0016
00000000000000000000000000000000:0000 0A 00000000:00000000 00:00000000 00000000
0 0 10656 1 ffff8801b266d040 299 0 0 2 -1
+ 3: 00000000000000000000000000000000:8E77
00000000000000000000000000000000:0000 0A 00000000:00000000 00:00000000 00000000
0 0 22300 1 ffff8801b2f5c780 299 0 0 2 -1
+
+ looking for local_address:PORT wher st = LISTEN (0x0A)
+ * ./include/net/tcp_states.h
+ * enum {
+ TCP_ESTABLISHED = 1,
+ TCP_SYN_SENT,
+ TCP_SYN_RECV,
+ TCP_FIN_WAIT1,
+ TCP_FIN_WAIT2,
+ TCP_TIME_WAIT,
+ TCP_CLOSE,
+ TCP_CLOSE_WAIT,
+ TCP_LAST_ACK,
+ TCP_LISTEN,
+ TCP_CLOSING,
+
+ TCP_MAX_STATES
+ */
+
+/************************************************************************/
+
+/* used internally */
+bool
+scanProcFileForPort(string sFilename, string sPid, unsigned int iPort)
+{
+ bool bMatch = false;
+ TSFile file;
+ int iLine = 0;
+ bool bParseDone = false;
+
+ // attempt to open file
+ TSDebug(DEBUG_TAG_INIT, "Trying to open proc file @ %s to determine
listening ports", sFilename.c_str());
+ file = TSfopen(sFilename.c_str(), "r");
+ if (file == NULL) {
+ TSError("Failed to open proc tcp file of %s. Error=%s",
sFilename.c_str(), strerror(errno));
+ return false;
+ }
+
+ TSDebug(DEBUG_TAG_INIT, "Successfully opened %s file",
sFilename.c_str());
+
+ char buffer[1024];
+ memset(buffer, 0, sizeof (buffer));
+
+ while (TSfgets(file, buffer, sizeof (buffer) - 1) != NULL &&
!bParseDone) {
+ char *eol = strstr(buffer, "\r\n");
+ if (!eol)
+ eol = strchr(buffer, '\n');
+ if (eol)
+ *eol = 0; // remove ending LF or CRLF
+
+ // TSDebug(DEBUG_TAG_INIT, "Parsing line: %s", buffer);
+ ++iLine;
+ if (iLine == 1) { // ignore header line
+ continue;
+ }
+ vector<string> vParts;
+ stringExplode(string(buffer), string(" "), &vParts);
+ // part 3 is status
+ unsigned int iStatus = 0;
+ sscanf(vParts[3].c_str(), "%x", &iStatus);
+ if (iStatus == TCP_LISTEN) {
+ vector<string> vLocalParts;
+ stringExplode(vParts[1], string(":"), &vLocalParts); // part 1 is
localaddr
+ unsigned int iLPort = 0;
+ sscanf(vLocalParts[1].c_str(), "%x", &iLPort);
+ TSDebug(DEBUG_TAG_INIT, "Found listening port %d", iLPort);
+ if (iLPort == iPort) {
+ string sLabel = string("socket:[" + vParts[9] + "]");
+ // find inode in /proc/{pid}/fd/
+ string sDir = "/proc/" + string(sPid) + "/fd";
+
+ DIR *dp;
+ struct dirent *dirp;
+ if ((dp = opendir(sDir.c_str())) == NULL) {
+ TSDebug(DEBUG_TAG_INIT, "Failed to open directory %s, %s",
sDir.c_str(), strerror(errno));
+ continue;
+ }
+
+ while ((dirp = readdir(dp)) != NULL && !bParseDone) {
+ //TSDebug(DEBUG_TAG_INIT, "File in %s = %s inode=%d",
sDir.c_str(),dirp->d_name,dirp->d_ino);
+ string sPath = sDir + "/" + dirp->d_name;
+ char sBuf[256];
+ ssize_t iCount = readlink(sPath.c_str(), sBuf, sizeof (sBuf));
+ if (iCount > 0) {
+ string sLink(sBuf, iCount);
+ if (sLink.compare(sLabel) == 0) {
+ TSDebug(DEBUG_TAG_INIT, "Found that port %d is opened for
listening by pid %s", iLPort, sPid.c_str());
+ bParseDone = true;
+ bMatch = true;
+ }
+ }
+ }
+ closedir(dp);
+ }
+ }
+ /*
+ for(int i=0;i<vParts.size();i++)
+ {
+ TSDebug(DEBUG_TAG_INIT, "part[%d]='%s'", i, vParts[i].c_str());
+ }
+ */
+ }
+
+ TSfclose(file);
+
+ return bMatch;
+}
+
+/************************************************************************/
+bool
+isPortSelf(unsigned int iPort)
+{
+ pid_t pid = getpid();
+ char sPid[10];
+ bool bMatch = false;
+
+ string sFileName;
+ // open file @ /proc/{pid}/net/tcp
+
+
+ sprintf(sPid,"%d",pid);
+
+ // look for IPv4 listener first
+ sFileName = "/proc/" + string(sPid) + "/net/tcp";
+ bMatch = scanProcFileForPort(sFileName,sPid, iPort);
+ if(!bMatch) { // did not find IPv4 listener, check for IPv6
+ sFileName = "/proc/" + string(sPid) + "/net/tcp6";
+ bMatch = scanProcFileForPort(sFileName,sPid, iPort);
+ }
+ return bMatch;
+}
+
+/************************************************************************/
+struct hostent *
+getHostIp(string hName, struct hostent *h, char *buf, int buflen)
+{
+ int res, err;
+ struct hostent *hp = NULL;
+
+ res = gethostbyname_r(hName.c_str(), h, buf, buflen, &hp, &err);
+ if ((res == 0) && (hp != NULL)) {
+ return hp;
+ } else {
+ TSDebug(DEBUG_TAG_INIT, "gethostbyname_r failed for %s. Error=%s",
hName.c_str(), strerror(err));
+ }
+ return NULL;
+}
+
+
+/************************************************************************/
+/*
+ * *** WARNING *** You will need to run the carp plugin with
traffic_manager for it to detect
+ * itself and to forward directly to the origin. It will not work by
running traffic_server directly!
+ */
--- End diff --
Why? Because `traffic_manager` opens the ports and so only if it is running
will the port scan work? In that case, why not wait until
`TS_LIFECYCLE_PORTS_READY_HOOK`?
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
