PenTest/nmap
1
0
Fork 0
mirror of https://github.com/nmap/nmap.git synced 2025-12-17 21:19:01 +00:00
Code Issues Projects Releases Wiki Activity

Improve the efficiency of loading the nmap-services file. We now use an STL map

Browse Source 
instead of a custom hash table and an STL list instead of a custom linked list.
The biggest gain comes from using the list.sort method rather than inserting
ports in sorted order (equivalent to insertion sort). The new code passes
Doug's p-switch-tests.

Here are time comparisons, using the old and new services code, and using the
standard nmap-services file and the 65535-port nmap-services-huge. The times
are the duration of the call to nmap_services_init. Three trials were done for
each case, except for the old-code/nmap-services-huge case.

nmap-services:
old code:   0.215  0.201  0.227  (average   0.214 s)
new code:   0.025  0.022  0.023  (average   0.023 s)

nmap-services-huge:
old code: 441.014                (average 441.014 s)
new code:   0.984  0.975  0.978  (average   0.979 s)
This commit is contained in:
david
2008-08-13 01:19:09 +00:00
parent 931285f765
commit 3a67da3a7e
2 changed files with 127 additions and 121 deletions
Download Patch File Download Diff File Expand all files Collapse all files

210
services.cc
View File

@@ -99,17 +99,49 @@
/* $Id$ */
#include <list>
#include <map>
#include "services.h"
#include "NmapOps.h"
#include "charpool.h"
#include "nmap_error.h"
#include "utils.h"
/* This structure is the key for looking up services in the
port/proto -> service map. */
struct port_spec {
int portno; /* Network byte order */
std::string proto;
/* Sort in the usual nmap-services order. */
bool operator<(const port_spec& other) const {
if (this->portno < other.portno)
return true;
else if (this->portno > other.portno)
return false;
else
return this->proto < other.proto;
}
};
/* This is a servent augmented by a frequency ratio. */
struct service_node : public servent {
public:
double ratio;
};
/* Compare the ratios of two service nodes for top-ports purposes. Larger ratios
come before smaller. */
bool service_node_ratio_compare(const service_node& a, const service_node& b) {
return a.ratio > b.ratio;
}
extern NmapOps o;
static int numtcpports = 0;
static int numudpports = 0;
static struct service_list *service_table[SERVICE_TABLE_SIZE];
static struct service_list *sorted_services = NULL;
static std::map<port_spec, service_node> service_table;
static std::list<service_node> services_by_ratio;
static int services_initialized = 0;
static int ratio_format = 0; // 0 = /etc/services no-ratio format. 1 = new nmap format
@@ -123,7 +155,6 @@ static int nmap_services_init() {
char *p;
char line[1024];
int lineno = 0;
struct service_list *current, *previous, *sp;
int res;
double ratio;
int ratio_n, ratio_d;
@@ -159,8 +190,6 @@ static int nmap_services_init() {
/* Record where this data file was found. */
o.loaded_data_files["nmap-services"] = filename;
memset(service_table, 0, sizeof(service_table));
while(fgets(line, sizeof(line), fp)) {
lineno++;
p = line;
@@ -191,21 +220,18 @@ static int nmap_services_init() {
portno = htons(portno);
port_spec ps;
ps.portno = portno;
ps.proto = proto;
/* Now we make sure our service table doesn't have duplicates */
for(current = service_table[portno % SERVICE_TABLE_SIZE], previous = NULL;
current; current = current->next) {
if (portno == (u16) current->servent->s_port &&
strcasecmp(proto, current->servent->s_proto) == 0) {
if (o.debugging) {
std::map<port_spec, service_node>::iterator i;
i = service_table.find(ps);
if (i != service_table.end()) {
if (o.debugging)
error("Port %d proto %s is duplicated in services file %s", ntohs(portno), proto, filename);
}
break;
}
previous = current;
}
/* Current service in the file was a duplicate, get another one */
if (current)
continue;
}
if (strncasecmp(proto, "tcp", 3) == 0) {
numtcpports++;
@@ -223,41 +249,21 @@ static int nmap_services_init() {
continue;
}
current = (struct service_list *) cp_alloc(sizeof(struct service_list));
current->servent = (struct servent *) cp_alloc(sizeof(struct servent));
current->ratio = ratio;
current->next = NULL;
if (previous == NULL) {
service_table[portno % SERVICE_TABLE_SIZE] = current;
} else {
previous->next = current;
}
current->servent->s_name = cp_strdup(servicename);
current->servent->s_port = portno;
current->servent->s_proto = cp_strdup(proto);
current->servent->s_aliases = NULL;
struct service_node sn;
sp = (struct service_list *) cp_alloc(sizeof(struct service_list));
sp->servent = current->servent;
sp->ratio = current->ratio;
sp->next = NULL;
sn.s_name = cp_strdup(servicename);
sn.s_port = portno;
sn.s_proto = cp_strdup(proto);
sn.s_aliases = NULL;
sn.ratio = ratio;
if (sorted_services == NULL || sorted_services->ratio < sp->ratio) {
sp->next = sorted_services;
sorted_services = sp;
} else
for (current=sorted_services;;current=current->next) {
if (current->next == NULL) {
current->next = sp;
break;
} else if (current->next->ratio < sp->ratio) {
sp->next = current->next;
current->next = sp;
break;
}
service_table[ps] = sn;
services_by_ratio.push_back(sn);
}
}
/* Sort the list of ports sorted by frequency for top-ports purposes. */
services_by_ratio.sort(service_node_ratio_compare);
fclose(fp);
services_initialized = 1;
@@ -273,52 +279,47 @@ static int nmap_services_init() {
*/
int addportsfromservmask(char *mask, u8 *porttbl, int range_type) {
struct service_list *current;
int bucket,t=0;
std::map<port_spec, service_node>::iterator i;
int t = 0;
if (!services_initialized && nmap_services_init() == -1)
fatal("%s: Couldn't get port numbers", __func__);
for(bucket = 0; bucket < SERVICE_TABLE_SIZE; bucket++) {
for(current = service_table[bucket % SERVICE_TABLE_SIZE]; current; current = current->next) {
if (wildtest(mask, current->servent->s_name)) {
if ((range_type & SCAN_TCP_PORT) && strcmp(current->servent->s_proto, "tcp") == 0) {
porttbl[ntohs(current->servent->s_port)] |= SCAN_TCP_PORT;
for (i = service_table.begin(); i != service_table.end(); i++) {
service_node& current = i->second;
if (wildtest(mask, current.s_name)) {
if ((range_type & SCAN_TCP_PORT) && strcmp(current.s_proto, "tcp") == 0) {
porttbl[ntohs(current.s_port)] |= SCAN_TCP_PORT;
t++;
}
if ((range_type & SCAN_UDP_PORT) && strcmp(current->servent->s_proto, "udp") == 0) {
porttbl[ntohs(current->servent->s_port)] |= SCAN_UDP_PORT;
if ((range_type & SCAN_UDP_PORT) && strcmp(current.s_proto, "udp") == 0) {
porttbl[ntohs(current.s_port)] |= SCAN_UDP_PORT;
t++;
}
}
}
}
return t;
}
/* Port must be in network byte order. */
struct servent *nmap_getservbyport(int port, const char *proto) {
struct service_list *current;
std::map<port_spec, service_node>::iterator i;
port_spec ps;
if (nmap_services_init() == -1)
return NULL;
for(current = service_table[port % SERVICE_TABLE_SIZE];
current; current = current->next) {
if (((u16) port == (u16) current->servent->s_port) &&
strcmp(proto, current->servent->s_proto) == 0)
return current->servent;
}
ps.portno = port;
ps.proto = proto;
i = service_table.find(ps);
if (i != service_table.end())
return &i->second;
/* Couldn't find it ... oh well. */
return NULL;
}
@@ -336,18 +337,20 @@ static int port_compare(const void *a, const void *b) {
// called when you use a non-default top-ports or port-ratio value TOGETHER WITH
// a -p portlist.
static int is_port_member(struct scan_lists *ptsdata, struct service_list *serv) {
static bool is_port_member(const struct scan_lists *ptsdata, const struct service_node *serv) {
int i;
if (serv->servent->s_proto[0] == 't') {
if (strcmp(serv->s_proto, "tcp") == 0) {
for (i=0; i<ptsdata->tcp_count; i++)
if (ntohs(serv->servent->s_port) == ptsdata->tcp_ports[i]) return 1;
} else {
if (ntohs(serv->s_port) == ptsdata->tcp_ports[i])
return true;
} else if (strcmp(serv->s_proto, "udp") == 0) {
for (i=0; i<ptsdata->udp_count; i++)
if (ntohs(serv->servent->s_port) == ptsdata->udp_ports[i]) return 1;
if (ntohs(serv->s_port) == ptsdata->udp_ports[i])
return true;
}
return 0;
return false;
}
// gettoppts() sets its third parameter, a scan_list, with the most
@@ -367,7 +370,8 @@ void gettoppts(double level, char *portlist, struct scan_lists * ports) {
int ti=0, ui=0;
struct scan_lists ptsdata = { 0 };
bool ptsdata_initialized = false;
struct service_list *current;
const struct service_node *current;
std::list<service_node>::iterator i;
if (!services_initialized && nmap_services_init() == -1)
fatal("%s: Couldn't get port numbers", __func__);
@@ -403,13 +407,18 @@ void gettoppts(double level, char *portlist, struct scan_lists * ports) {
ptsdata_initialized = true;
}
if (level < 1) {
for (current=sorted_services; current; current=current->next) {
if (ptsdata_initialized && !is_port_member(&ptsdata, current)) continue;
for (i = services_by_ratio.begin(); i != services_by_ratio.end(); i++) {
current = &(*i);
if (ptsdata_initialized && !is_port_member(&ptsdata, current))
continue;
if (current->ratio >= level) {
if (o.TCPScan() && current->servent->s_proto[0] == 't') ports->tcp_count++;
else if (o.UDPScan() && current->servent->s_proto[0] == 'u') ports->udp_count++;
} else break;
if (o.TCPScan() && strcmp(current->s_proto, "tcp") == 0)
ports->tcp_count++;
else if (o.UDPScan() && strcmp(current->s_proto, "udp") == 0)
ports->udp_count++;
} else {
break;
}
}
if (ports->tcp_count)
@@ -420,15 +429,18 @@ void gettoppts(double level, char *portlist, struct scan_lists * ports) {
ports->prots = NULL;
for (current=sorted_services;current;current=current->next) {
if (ptsdata_initialized && !is_port_member(&ptsdata, current)) continue;
for (i = services_by_ratio.begin(); i != services_by_ratio.end(); i++) {
current = &(*i);
if (ptsdata_initialized && !is_port_member(&ptsdata, current))
continue;
if (current->ratio >= level) {
if (o.TCPScan() && current->servent->s_proto[0] == 't')
ports->tcp_ports[ti++] = ntohs(current->servent->s_port);
else if (o.UDPScan() && current->servent->s_proto[0] == 'u')
ports->udp_ports[ui++] = ntohs(current->servent->s_port);
} else break;
if (o.TCPScan() && strcmp(current->s_proto, "tcp") == 0)
ports->tcp_ports[ti++] = ntohs(current->s_port);
else if (o.UDPScan() && strcmp(current->s_proto, "udp") == 0)
ports->udp_ports[ui++] = ntohs(current->s_port);
} else {
break;
}
}
} else if (level >= 1) {
if (level > 65536)
@@ -438,7 +450,6 @@ void gettoppts(double level, char *portlist, struct scan_lists * ports) {
ports->tcp_count = MIN((int) level, numtcpports);
ports->tcp_ports = (unsigned short *)safe_zalloc(ports->tcp_count * sizeof(unsigned short));
}
if (o.UDPScan()) {
ports->udp_count = MIN((int) level, numudpports);
ports->udp_ports = (unsigned short *)safe_zalloc(ports->udp_count * sizeof(unsigned short));
@@ -446,13 +457,14 @@ void gettoppts(double level, char *portlist, struct scan_lists * ports) {
ports->prots = NULL;
for (current=sorted_services;current && (ti < ports->tcp_count || ui < ports->udp_count);current=current->next) {
if (ptsdata_initialized && !is_port_member(&ptsdata, current)) continue;
if (o.TCPScan() && current->servent->s_proto[0] == 't' && ti < ports->tcp_count)
ports->tcp_ports[ti++] = ntohs(current->servent->s_port);
else if (o.UDPScan() && current->servent->s_proto[0] == 'u' && ui < ports->udp_count)
ports->udp_ports[ui++] = ntohs(current->servent->s_port);
for (i = services_by_ratio.begin(); i != services_by_ratio.end(); i++) {
current = &(*i);
if (ptsdata_initialized && !is_port_member(&ptsdata, current))
continue;
if (o.TCPScan() && strcmp(current->s_proto, "tcp") == 0 && ti < ports->tcp_count)
ports->tcp_ports[ti++] = ntohs(current->s_port);
else if (o.UDPScan() && strcmp(current->s_proto, "udp") == 0 && ui < ports->udp_count)
ports->udp_ports[ui++] = ntohs(current->s_port);
}
if (ti < ports->tcp_count) ports->tcp_count = ti;

6
services.h
View File

@@ -122,12 +122,6 @@
#define SCAN_UDP_PORT (1 << 1)
#define SCAN_PROTOCOLS (1 << 2)
struct service_list {
struct servent *servent;
double ratio;
struct service_list *next;
};
int addportsfromservmask(char *mask, u8 *porttbl, int range_type);
struct servent *nmap_getservbyport(int port, const char *proto);
void gettoppts(double level, char *portlist, struct scan_lists * ports);