added hand-coded inode-to-process mapping

inode2prog.cpp

@@ -0,0 +1,183 @@
+#include <sys/types.h>
+#include <errno.h>
+#include <string.h>
+#include <dirent.h>
+#include <ctype.h>
+#include <iostream.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string>
+#include <map>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "inode2prog.h"
+
+/* maps from inode to program-struct */
+std::map <unsigned long, prg_node *> inodeproc;
+
+bool is_number (char * string) {
+	while (*string) {
+		if (!isdigit (*string))
+			return false;
+		string++;
+	}
+	return true;
+}
+
+unsigned long str2ulong (char * ptr) {
+	unsigned long retval = 0;
+
+	while ((*ptr >= '0') && (*ptr <= '9')) {
+		retval *= 10;
+		retval += *ptr - '0';
+		ptr++;
+	}
+	return retval;
+}
+int str2int (char * ptr) {
+	int retval = 0;
+
+	while ((*ptr >= '0') && (*ptr <= '9')) {
+		retval *= 10;
+		retval += *ptr - '0';
+		ptr++;
+	}
+	return retval;
+}
+
+char * getprogname (char * pid) {
+	int filenamelen = 14 + strlen(pid) + 1; 
+	int bufsize = 80;
+	char buffer [bufsize];
+	char * filename = (char *) malloc (filenamelen);
+	snprintf (filename, filenamelen, "/proc/%s/cmdline", pid);
+	int fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		fprintf (stderr, "Error opening %s: %s\n", filename, strerror(errno));
+		exit(3);
+		return NULL;
+	}
+	int length = read (fd, buffer, bufsize);
+	if (close (fd)) {
+		cout << "Error closing file: " << strerror(errno) << endl;
+		exit(34);
+	}
+	if (length < bufsize - 1)
+		buffer[length]='\0';
+
+	char * retval;
+
+	if ((retval = strrchr(buffer, '/')))
+		retval++;
+	else 
+		retval = buffer; 
+
+	return strdup(retval);
+}
+
+void get_info_by_linkname (char * pid, char * linkname) {
+	if (strncmp(linkname, "socket:[", 8) == 0) {
+		char * ptr = linkname + 8;
+		unsigned long inode = str2ulong(ptr);
+
+		char * progname = getprogname (pid);
+
+		//std::cout << "Found socket with inode " << inode << " and pid " << pid << " and progname " << progname << "\n";
+		prg_node * newnode = (prg_node *) malloc (sizeof (struct prg_node));
+		newnode->inode = inode;
+		newnode->pid = str2int(pid);
+		// TODO progname could be more memory-efficient
+		strncpy (newnode->name, progname, PROGNAME_WIDTH);
+		free (progname);
+		inodeproc[inode] = newnode;
+	} else {
+		//std::cout << "Linkname looked like: " << linkname << endl;
+	}
+}
+
+void get_info_for_pid(char * pid) {
+	size_t dirlen = 10 + strlen(pid);
+	char * dirname = (char *) malloc (dirlen * sizeof(char));
+	snprintf(dirname, dirlen, "/proc/%s/fd", pid);
+
+	//std::cout << "Entering directory " << dirname << std::endl;
+
+	DIR * dir = opendir(dirname);
+
+	if (!dir)
+	{
+		std::cout << "Couldn't open dir " << dirname << ": " << strerror(errno) << "\n";
+		free (dirname);
+		return;
+	}
+
+	/* walk through /proc/%s/fd/... */
+	dirent * entry;
+	while ((entry = readdir(dir))) {
+		if (entry->d_type != DT_LNK)
+			continue;
+		//std::cout << "Looking at: " << entry->d_name << std::endl;
+
+		int fromlen = dirlen + strlen(entry->d_name) + 1;
+		char * fromname = (char *) malloc (fromlen * sizeof(char));
+		snprintf (fromname, fromlen, "%s/%s", dirname, entry->d_name);
+
+		//std::cout << "Linking from: " << fromname << std::endl;
+
+		int linklen = 80;
+		char linkname [linklen];
+		int usedlen = readlink(fromname, linkname, linklen-1);
+		if (ROBUST)
+			assert (usedlen < linklen);
+		linkname[usedlen] = '\0';
+		//std::cout << "Linking to: " << linkname << std::endl;
+		get_info_by_linkname (pid, linkname);
+		free (fromname);
+	}
+	closedir(dir);
+	free (dirname);
+}
+
+void reread_mapping () {
+	DIR * proc = opendir ("/proc");
+
+	if (proc == 0) {
+		std::cerr << "Error getting inode-to-pid mapping\n";
+		exit(1);
+	}
+
+	dirent * entry;
+
+	while ((entry = readdir(proc))) {
+		if (entry->d_type != DT_DIR) continue;
+
+		if (! is_number (entry->d_name)) continue;
+
+		//std::cout << "Getting info for " << entry->d_name << std::endl;
+		get_info_for_pid(entry->d_name);
+	}
+	//std::cout << "End...\n";
+	closedir(proc);
+}
+
+struct prg_node * findPID (unsigned long inode)
+{
+	/* we first look in inodeproc */
+	struct prg_node * node = inodeproc[inode];
+	
+	if (node != NULL)
+		return node;
+
+	reread_mapping();
+	
+	return inodeproc[inode];
+}
+
+void prg_cache_clear() {};
+
+/*void main () {
+	std::cout << "Fooo\n";
+	reread_mapping();
+	std::cout << "Haihai\n";
+}*/

inode2prog.h

@@ -0,0 +1,16 @@
+/* this should be called quickly after the packet
+ * arrived, since the inode may disappear from the table
+ * quickly, too :) */
+
+#include "nethogs.h"
+// #define PROGNAME_WIDTH 200
+
+struct prg_node {
+    long inode;
+    int pid;
+    char name[PROGNAME_WIDTH];
+};
+
+struct prg_node * findPID (unsigned long inode);
+
+void prg_cache_clear();