Related
linux 2.6
I am writing a LKM. I need to compress and decompress on the fly many different chunks of text.
I prefer to call kernel api, avoiding to include and compile external libraries.
Are there kernel Api to compress and decompress memory ?
source and destination buffers can be both in kernel memory or one in kernel the other in user space.
Not sure why kernel.org excludes the compression part.
One may need to mimic from its official skcipher example, in which the procedure is like below:
tfm = crypto_alloc_tfm("yourAlg",
CRYPTO_TFM_MODE_yourAlg);
req = skcipher_request_alloc(tfm, GFP_KERNEL);
skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
test_tfm_cb,
result);
crypto_cipher_setkey(tfm, key, keylength);
crypto_cipher_encrypt(tfm, &scatterlist,
numlists);
tfm_request_free(req);
crypto_free_tfm(tfm);
Notice kernel now is moving to async, however callback is not shown in latest header file.
/**
* acomp_request_set_callback() -- Sets an asynchronous callback
*
* Callback will be called when an asynchronous operation on a given
* request is finished.
*
* #req: request that the callback will be set for
* #flgs: specify for instance if the operation may backlog
* #cmlp: callback which will be called
* #data: private data used by the caller
*/
static inline void acomp_request_set_callback(struct acomp_req *req,
u32 flgs,
crypto_completion_t cmpl,
void *data)
{
req->base.complete = cmpl;
req->base.data = data;
req->base.flags = flgs;
}
Example code:
struct comp_testvec tv, int mode;
int ilen = tv.inlen;
char *str_input = tv.input;
int olen = tv.outlen;
char *str_output = tv.output;
struct scatterlist sg[2];
struct scatterlist sg2[2];
char *input;
char *output;
char *input2;
char *output2;
struct acomp_req *req;
struct crypto_acomp *tfm;
struct tcrypt_result result;
int ret = 0;
input = kmalloc(ilen, GFP_KERNEL);
output = kmalloc(olen, GFP_KERNEL);
input2 = kmalloc(olen, GFP_KERNEL);
output2 = kmalloc(ilen, GFP_KERNEL);
char *driver = tv.alg;
tfm = crypto_alloc_acomp(driver, CRYPTO_ALG_TYPE_ACOMPRESS,
CRYPTO_ALG_TYPE_ACOMPRESS_MASK);
if (IS_ERR(tfm)) {
printk(KERN_ERR "alg: acomp: Failed to load transform for "
"%s: %ld\n", driver, PTR_ERR(tfm));
return PTR_ERR(tfm);
}
init_completion(&result.completion);
if (mode == 0)
{
//zip
memcpy(input,str_input,ilen);
printk("input => %s\n", input);
print_hex_dump(KERN_CONT, "| ", DUMP_PREFIX_OFFSET, 16, 1, input, ilen, false);
printk("alg => %s\n",driver);
sg_init_one(&sg[0], input, ilen);
sg_init_one(&sg[1], output, COMP_BUF_SIZE);
req = acomp_request_alloc(tfm);
if(!req)
{
printk("error req = null\n");
crypto_free_acomp(tfm);
return -1;
}
acomp_request_set_params(req, &sg[0], &sg[1], ilen, COMP_BUF_SIZE);
acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
tcrypt_complete, &result);
ret = crypto_acomp_compress(req);
if(ret == -EINPROGRESS || ret == -EBUSY)
{
ret = wait_for_completion_interruptible(
&result.completion);
if (!ret && !((ret = result.err)))
{
reinit_completion(&result.completion);
}
}
else if(ret == 0)
{
printk("succ\n");
}
else
{
printk("error ret = %d\n",ret);
goto out;
}
printk("compress => \n");
print_hex_dump(KERN_CONT, "| ", DUMP_PREFIX_OFFSET, 16, 1, output, olen, false);
} else if (mode == 1) {
//unzip
memcpy(input2,str_output,olen);
printk("input => \n");
print_hex_dump(KERN_CONT, "| ", DUMP_PREFIX_OFFSET, 16, 1, input2, olen, false);
char *driver = tv.alg;
printk("alg => %s\n",driver);
//sg init
sg_init_one(&sg2[0], input2, ilen);
sg_init_one(&sg2[1], output2, COMP_BUF_SIZE);
req = acomp_request_alloc(tfm);
if(!req)
{
printk("error req = null\n");
crypto_free_acomp(tfm);
return -1;
}
acomp_request_set_params(req, &sg2[0], &sg2[1], ilen, COMP_BUF_SIZE);
acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
tcrypt_complete, &result);
ret = crypto_acomp_decompress(req);
if(ret == -EINPROGRESS || ret == -EBUSY)
{
ret = wait_for_completion_interruptible(
&result.completion);
if (!ret && !((ret = result.err)))
{
reinit_completion(&result.completion);
}
}
else if(ret == 0)
{
printk("succ\n");
}
else
{
printk("error ret = %d\n",ret);
goto out;
}
printk("decompress => %s\n", output2);
print_hex_dump(KERN_CONT, "| ", DUMP_PREFIX_OFFSET, 16, 1, output2, ilen, false);
Given an infinite stream of characters and a list L of strings, create a function that calls an external API when a word in L is recognized during the processing of the stream.
Example:
L = ["ok","test","one","try","trying"]
stream = a,b,c,o,k,d,e,f,t,r,y,i,n,g.............
The call to external API will happen when 'k' is encountered, again when the 'y' is encountered, and again at 'g'.
My idea:
Create trie out of the list and navigate the nodes as you read from stream in linear time. But there would be a bug if you just do simple trie search.
Assume you have words "abxyz" and "xyw" and your input is "abxyw".In this case you can't recognize "xyw" with trie.
So search should be modified as below:
let's take above use case "abxyw". We start the search and we find we have all the element till 'x'. Moment you get 'x' you have two options:
Check if the current element is equal to the head of trie and if it is equal to head of trie then call recursive search.
Continue till the end of current word. In this case for your given input it will return false but for the recursive search we started in point 1, it will return true.
Below is my modified search but I think it has bugs and can be improved. Any suggestions?
#define SIZE 26
struct tri{
int complete;
struct tri *child[SIZE];
};
void insert(char *c, struct tri **t)
{
struct tri *current = *t;
while(*c != '\0')
{
int i;
int letter = *c - 'a';
if(current->child[letter] == NULL) {
current->child[letter] = malloc(sizeof(*current));
memset(current->child[letter], 0, sizeof(struct tri));
}
current = current->child[letter];
c++;
}
current->complete = 1;
}
struct tri *t;
int flag = 0;
int found(char *c, struct tri *tt)
{
struct tri *current = tt;
if (current == NULL)
return 0;
while(*c != '\0')
{
int i;
int letter = *c - 'a';
/* if this is the first char then recurse from begining*/
if (t->child[letter] != NULL)
flag = found(c+1, t->child[letter]);
if (flag == 1)
return 1;
if(!flag && current->child[letter] == NULL) {
return 0;
}
current = current->child[letter];
c++;
}
return current->complete;
}
int main()
{
int i;
t = malloc(sizeof(*t));
t->complete = 0;
memset(t, 0, sizeof(struct tri));
insert("weathez", &t);
insert("eather", &t);
insert("weather", &t);
(1 ==found("weather", t))?printf("found\n"):printf("not found\n");
return 0;
}
What you want to do is exactly what Aho-Corasick algorithm does.
You can take a look at my Aho-Corasick implementation. It's contest-oriented, so maybe not focused on readability but I think it's quite clear:
typedef vector<int> VI;
struct Node {
int size;
Node *fail, *output;
VI id;
map<char, Node*> next;
};
typedef pair<Node*, Node*> P;
typedef map<char, Node*> MCP;
Node* root;
inline void init() {
root = new Node;
root->size = 0;
root->output = root->fail = NULL;
}
Node* add(string& s, int u, int c = 0, Node* p = root) {
if (p == NULL) {
p = new Node;
p->size = c;
p->fail = p->output = NULL;
}
if (c == s.size()) p->id.push_back(u);
else {
if (not p->next.count(s[c])) p->next[s[c]] = NULL;
p->next[s[c]] = add(s, u, c + 1, p->next[s[c]]);
}
return p;
}
void fill_fail_output() {
queue<pair<char, P> > Q;
for (MCP::iterator it=root->next.begin();
it!=root->next.end();++it)
Q.push(pair<char, P> (it->first, P(root, it->second)));
while (not Q.empty()) {
Node *pare = Q.front().second.first;
Node *fill = Q.front().second.second;
char c = Q.front().first; Q.pop();
while (pare != root && !pare->fail->next.count(c))
pare=pare->fail;
if (pare == root) fill->fail = root;
else fill->fail = pare->fail->next[c];
if (fill->fail->id.size() != 0)
fill->output = fill->fail;
else fill->output = fill->fail->output;
for (MCP::iterator it=fill->next.begin();
it!=fill->next.end();++it)
Q.push(pair<char,P>(it->first,P(fill,it->second)));
}
}
void match(int c, VI& id) {
for (int i = 0; i < id.size(); ++i) {
cout << "Matching of pattern " << id[i];
cout << " ended at " << c << endl;
}
}
void search(string& s) {
int i = 0, j = 0;
Node *p = root, *q;
while (j < s.size()) {
while (p->next.count(s[j])) {
p = p->next[s[j++]];
if (p->id.size() != 0) match(j - 1, p->id);
q = p->output;
while (q != NULL) {
match(j - 1, q->id);
q = q->output;
}
}
if (p != root) {
p = p->fail;
i = j - p->size;
}
else i = ++j;
}
}
void erase(Node* p = root) {
for (MCP::iterator it = p->next.begin();
it != p->next.end(); ++it)
erase(it->second);
delete p;
}
int main() {
init();
int n;
cin >> n;
for (int i = 0; i < n; ++i) {
string s;
cin >> s;
add(s, i);
}
fill_fail_output();
string text;
cin >> text;
search(text);
erase(root);
}
so... context: I'm doing a layer 2 protocol for flexible forwarding in vehicular environment (for now my testbed is in virtual machines), this should take in consideration a different number of interfaces (for multihoming) and multihop.
So what I have:
A way of broadcasting hop-by-hop the service provider.
What I'm triyng to do:
A way to register a session all the way from the client to the provider (And here is the problem)
Problem: I have two types of packets
1st is listened correctly and data payload starts with a 1
2nd for some reason is not detected but I can see the packet is sent and correct with tcpdump
Since I have to register in the application the interface where the connection is made I used select() which seems to be part of the problem since I only guessed how it was used and I'm kind of in the dark about this.
UPDATED v3:
Okay so as soon as I removed most of the stuff about only sending on a specific interface all the stuff worked perfectly (I still need to clean this code... it's kind of messy). Here is code if someone is interested:
#define __STDC_FORMAT_MACROS
#include <inttypes.h>
#include <time.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <ifaddrs.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <arpa/inet.h>
#include <linux/if_packet.h>
#include <net/ethernet.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <netinet/in.h>
#define ETH_P_CUSTOM 0x0801 /* EtherType of Current Used Protocol*/
#define BUF_SIZE 1024
typedef enum {
false, true
} Bool; /* Boolean Definition*/
typedef struct Stat {
uint8_t maxSocket; /*Number of sockets to use in receive*/
uint8_t nInterfaces; /*Number of interfaces owned by this machine*/
uint8_t nSession; /*Number of Sessions Known in the linked list*/
uint8_t upMac[ETH_ALEN]; /*MAC of this host upstream parent*/
uint8_t nHops; /*Hops to Provider*/
char ifName[IF_NAMESIZE + 1]; /*Interface to Provider*/
} Stat;
typedef struct Node {
uint64_t session; /*Client Session*/
uint8_t nextHop[ETH_ALEN]; /*Next-Hop to Client*/
char ifName[IF_NAMESIZE + 1]; /*Outgoing Interface that connects to Next-Hop*/
struct Node * next; /*Next Session*/
} Node;
typedef struct ifNode {
uint8_t ifIndex; /*Interface index*/
uint8_t sock; /*Index in array of sockets*/
uint8_t mac[ETH_ALEN]; /*Interface MAC*/
char ifName[IF_NAMESIZE + 1]; /*Interface Name*/
struct ifNode * next; /*Next Session*/
} ifNode;
Stat * op; /* Variable which tracks status of certain structures/variables*/
Node * first = NULL, *last = NULL; /* Edges of linked list */
ifNode * iffirst = NULL, *iflast = NULL; /* Edges of interface linked list */
int cargc;
char **cargv;
int receiveP();
int broadServ();
int announceSelf();
Node* create(uint64_t sess, uint8_t n[ETH_ALEN], char interface[IF_NAMESIZE]);
void insert_node(Node * p);
Node* search(uint64_t session);
void update(uint64_t session, Node * p);
ifNode* createif(uint8_t idx, uint8_t sock, uint8_t ifmac[ETH_ALEN],
char interface[IF_NAMESIZE]);
void insert_ifnode(ifNode * p);
ifNode* searchif(uint8_t idx, uint8_t mode);
void updateif(uint8_t idx, ifNode * p);
void display();
void displayif();
void ctrlcoverride(int sig) {
printf("\nCtrl-C - Signal Caught - Exiting\n\n");
printf(
"Current Upstream MAC: %02x:%02x:%02x:%02x:%02x:%02x - NHops : %u - At Interface %s\n\n",
op->upMac[0], op->upMac[1], op->upMac[2], op->upMac[3],
op->upMac[4], op->upMac[5], op->nHops, op->ifName);
display();
exit(EXIT_SUCCESS);
}
Node* create(uint64_t sess, uint8_t n[ETH_ALEN], char interface[IF_NAMESIZE]) {
Node * new = (Node *) malloc(sizeof(Node));
if (new == NULL) {
printf("Could not create new node\n");
return NULL;
} else {
strcpy(new->ifName, interface);
new->session = sess;
int i;
for (i = 0; i < ETH_ALEN; i++)
new->nextHop[i] = n[i];
new->next = NULL;
return new;
}
}
ifNode* createif(uint8_t idx, uint8_t sock, uint8_t ifmac[ETH_ALEN],
char interface[IF_NAMESIZE]) {
ifNode * new = (ifNode *) malloc(sizeof(ifNode));
if (new == NULL) {
printf("Could not create new interface node\n");
return NULL;
} else {
new->ifIndex = idx;
new->sock = sock;
strcpy(new->ifName, interface);
int i;
for (i = 0; i < ETH_ALEN; i++)
new->mac[i] = ifmac[i];
new->next = NULL;
return new;
}
}
void insert_node(Node * p) {
if (first == last && last == NULL) {
first = last = p;
first->next = NULL;
last->next = NULL;
} else {
last->next = p;
last = last->next;
last->next = NULL;
}
}
void insert_ifnode(ifNode * p) {
if (iffirst == iflast && iflast == NULL) {
iffirst = iflast = p;
iffirst->next = NULL;
iflast->next = NULL;
} else {
iflast->next = p;
iflast = iflast->next;
iflast->next = NULL;
}
}
Node* search(uint64_t session) {
if (first == last && last == NULL) {
return NULL;
} else {
Node * temp;
for (temp = first; temp != NULL; temp = temp->next) {
if (temp->session == session) {
return temp;
}
}
return NULL;
}
}
ifNode* searchif(uint8_t idx, uint8_t mode) {
if (iffirst == iflast && iflast == NULL) {
return NULL;
} else {
ifNode * temp;
for (temp = iffirst; temp != NULL; temp = temp->next) {
if (temp->ifIndex == idx && mode == 0) {
return temp;
} else if (temp->sock == idx && mode == 1) {
return temp;
}
}
return NULL;
}
}
void update(uint64_t session, Node * p) {
if (first == last && last == NULL) {
return;
} else {
Node * temp;
for (temp = first; temp != NULL; temp = temp->next) {
if (temp->session == session) {
strcpy(temp->ifName, p->ifName);
temp->next = p->next;
int i;
for (i = 0; i < ETH_ALEN; i++)
temp->nextHop[i] = p->nextHop[i];
return;
}
}
}
}
void updateif(uint8_t idx, ifNode * p) {
if (iffirst == iflast && iflast == NULL) {
return;
} else {
ifNode * temp;
for (temp = iffirst; temp != NULL; temp = temp->next) {
if (temp->ifIndex == idx) {
strcpy(temp->ifName, p->ifName);
temp->sock = p->sock;
temp->next = p->next;
int i;
for (i = 0; i < ETH_ALEN; i++)
temp->mac[i] = p->mac[i];
return;
}
}
}
}
void display() {
Node * temp = first;
while (temp != NULL) {
printf("Session %" PRIu64 " Through %s - NextHop at ", temp->session,
temp->ifName);
int i;
for (i = 0; i < ETH_ALEN; i++)
printf("%02x ", temp->nextHop[i]);
printf("\n");
temp = temp->next;
}
}
void displayif() {
ifNode * temp = iffirst;
while (temp != NULL) {
printf("Interface Index %u Socket Number %u - Name %s with MAC: ",
temp->ifIndex, temp->sock, temp->ifName);
int i;
for (i = 0; i < ETH_ALEN; i++)
printf("%02x ", temp->mac[i]);
printf("\n");
temp = temp->next;
}
}
uint8_t counter() {
Node * temp = first;
uint8_t counter = 0;
while (temp != NULL) {
counter++;
temp = temp->next;
}
return counter;
}
fd_set rfds;
int rec;
int main(int argc, char **argv) {
setbuf(stdout, NULL);
signal(SIGINT, ctrlcoverride);
cargc = argc;
cargv = argv;
/*Setting Base Variables to Initial Values*/
op = (Stat*) malloc(sizeof(Stat));
op->nSession = 0;
memset(op->ifName, 0, IF_NAMESIZE);
op->maxSocket = 0;
op->nHops = UINT8_MAX - 1;
int i;
for (i = 0; i < ETH_ALEN; i++) {
op->upMac[i] = 0x00;
}
memset(&rfds, 0, sizeof(fd_set));
FD_ZERO(&rfds);
if (argc != 2) {
printf("USAGE: sudo %s {provider|node|nodekey}\n", cargv[0]);
exit(EXIT_FAILURE);
} else if (!(strcmp(cargv[1], "provider") == 0
|| strcmp(cargv[1], "node") == 0 || strcmp(cargv[1], "nodekey") == 0)) {
printf("USAGE: sudo %s {provider|node|nodekey}\n", cargv[0]);
exit(EXIT_FAILURE);
}
if (strcmp(cargv[1], "nodekey") == 0) {
srand(time(NULL));
uint8_t myArray[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
insert_node(
create((uint64_t) (100 * ((float) rand() / RAND_MAX)), myArray,
"SOURCE"));
}
struct ifaddrs *ifaddr, *ifa;
if (getifaddrs(&ifaddr) == -1) {
perror("getifaddrs");
exit(EXIT_FAILURE);
}
for (ifa = ifaddr, op->nInterfaces = 0; ifa != NULL; ifa = ifa->ifa_next) {
if (ifa->ifa_addr == NULL)
continue;
if (ifa->ifa_addr->sa_family == AF_PACKET
&& strncmp(ifa->ifa_name, "lo", strlen("lo")) != 0
&& strncmp(ifa->ifa_name, "tap", strlen("tap")) != 0) {
op->nInterfaces++;
}
}
rec = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_CUSTOM));
int sockopt;
char ifName[IFNAMSIZ];
struct ifreq ifr;
for (i = 1, ifa = ifaddr; ifa != NULL;
ifa = ifa->ifa_next, i++) {
if (ifa->ifa_addr == NULL)
continue;
if (ifa->ifa_addr->sa_family == AF_PACKET
&& strncmp(ifa->ifa_name, "lo", strlen("lo")) != 0
&& strncmp(ifa->ifa_name, "tap", strlen("tap")) != 0) {
uint8_t sock;
if ((sock = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_CUSTOM)))
== -1) {
printf("socket() error: %u - %s\n", errno, strerror(errno));
return EXIT_FAILURE;
}
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &sockopt,
sizeof sockopt) == -1) {
printf("SO_REUSEADDR error: %u - %s\n", errno, strerror(errno));
close(sock);
return EXIT_FAILURE;
}
memset(&ifr, 0, sizeof(struct ifreq));
ifr.ifr_ifindex = i;
strcpy(ifr.ifr_name, ifa->ifa_name);
if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifa->ifa_name,
IF_NAMESIZE) == -1) {
printf("SO_BINDTODEVICE error: %u - %s\n", errno,
strerror(errno));
close(sock);
return EXIT_FAILURE;
}
struct sockaddr_ll sll;
sll.sll_family = AF_PACKET;
sll.sll_ifindex = i;
sll.sll_protocol = htons(ETH_P_CUSTOM);
if ((bind(sock, (struct sockaddr *) &sll, sizeof(sll))) == -1) {
perror("Error binding raw socket to interface\n");
exit(-1);
}
if ((ioctl(sock, SIOCGIFHWADDR, &ifr)) != 0) {
printf("SIOCGIFHWADDR error: %u - %s\n", errno,
strerror(errno));
return EXIT_FAILURE;
}
int j;
uint8_t ifmac[ETH_ALEN];
for (j = 0; j < ETH_ALEN; j++) {
ifmac[j] = (uint8_t) (ifr.ifr_hwaddr.sa_data)[j];
}
FD_SET(sock, &rfds);
op->maxSocket = (op->maxSocket < sock) ? sock : op->maxSocket;
insert_ifnode(createif(i, sock, ifmac, ifr.ifr_name));
}
}
displayif();
if (strcmp(cargv[1], "provider") == 0) {
struct ifreq if_mac; // interface
char * interface = "eth1";
int sockfd;
if ((sockfd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_CUSTOM))) == -1) {
printf("socket() error: %u - %s\n", errno, strerror(errno));
return EXIT_FAILURE;
}
memset(&if_mac, 0, sizeof(struct ifreq));
strncpy(if_mac.ifr_name, interface, IFNAMSIZ - 1);
if ((ioctl(sockfd, SIOCGIFHWADDR, &if_mac)) != 0) {
printf("SIOCGIFHWADDR error: %u - %s\n", errno, strerror(errno));
return EXIT_FAILURE;
}
int i;
for (i = 0; i < ETH_ALEN; i++)
op->upMac[i] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[i];
op->nHops = 0;
close(sockfd);
}
freeifaddrs(ifaddr);
int stat = 0;
while (1) {
if (strcmp(cargv[1], "provider") == 0) {
if ((stat = receiveP()) != 0)
return stat;
if ((stat = broadServ()) != 0)
return stat;
display();
usleep(100000);
} else if (strcmp(cargv[1], "node") == 0
|| strcmp(cargv[1], "nodekey") == 0) {
if ((stat = receiveP()) != 0)
return stat;
if ((stat = announceSelf()) != 0){
return stat;
}
if ((stat = broadServ()) != 0)
return stat;
display();
usleep(100000);
}
}
ifNode * temp = iffirst;
while (temp != NULL) {
close(temp->sock);
temp = temp->next;
}
exit(stat);
}
int receiveP() {
int stat = 0;
struct ifreq ifr;
struct sockaddr saddr;
long unsigned int numbytes = 0;
char buf[BUF_SIZE];
memset(buf, 0, BUF_SIZE);
struct ether_header *eh = (struct ether_header *) buf;
unsigned int saddr_size = sizeof saddr;
struct timeval tv;
tv.tv_sec = 3; /* 3 Secs Timeout */
tv.tv_usec = 0;
setsockopt(rec, SOL_SOCKET, SO_RCVTIMEO, (char *) &tv,
sizeof(struct timeval));
numbytes = recvfrom(rec, buf, BUF_SIZE, 0, &saddr, &saddr_size);
int len;
int ntable;
switch (buf[sizeof(struct ether_header)]) {
case 1:
if (buf[sizeof(struct ether_header) + 1] < op->nHops) {
op->upMac[0] = eh->ether_shost[0];
op->upMac[1] = eh->ether_shost[1];
op->upMac[2] = eh->ether_shost[2];
op->upMac[3] = eh->ether_shost[3];
op->upMac[4] = eh->ether_shost[4];
op->upMac[5] = eh->ether_shost[5];
op->nHops = buf[sizeof(struct ether_header) + 1] + 1;
memset(&ifr, 0, sizeof(struct ifreq));
memset(&ifr.ifr_name, 0, IF_NAMESIZE);
printf(
"Server %u Hops Away - Through %02x:%02x:%02x:%02x:%02x:%02x At Interface %s\n",
op->nHops, eh->ether_shost[0], eh->ether_shost[1],
eh->ether_shost[2], eh->ether_shost[3], eh->ether_shost[4],
eh->ether_shost[5], op->ifName);
printf("\n\n");
}
break;
case 2:
len = sizeof(struct ether_header) + 1;
ntable = buf[len++];
int j;
for (j = 0; j < ntable; j++, len++) {
if (search(buf[len]) == NULL) {
insert_node(create(buf[len], eh->ether_shost, ""));
}
}
break;
}
return stat;
}
int broadServ() {
int stat = 0;
int tx_len = 0;
char sendbuf[BUF_SIZE];
char ifName[IF_NAMESIZE - 1];
struct ether_header *eh = (struct ether_header *) sendbuf;
struct sockaddr_ll socket_address;
int i;
struct ifreq ifr, if_mac;
ifNode * temp = iffirst;
while (temp != NULL) {
/* Get the index of the interface to send on */
memset(&ifr, 0, sizeof(struct ifreq));
ifr.ifr_ifindex = temp->ifIndex;
if (ioctl(temp->sock, SIOCGIFNAME, &ifr) < 0)
perror("SIOCGIFINDEX");
memset(ifName, 0, IF_NAMESIZE - 1);
strncpy(ifName, ifr.ifr_name, IF_NAMESIZE - 1);
/* Get the MAC address of the interface to send on */
memset(&if_mac, 0, sizeof(struct ifreq));
strncpy(if_mac.ifr_name, ifName, IFNAMSIZ - 1);
if (ioctl(temp->sock, SIOCGIFHWADDR, &if_mac) < 0)
perror("SIOCGIFHWADDR");
if (((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[0] == 0x00
&& ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[1] == 0x00
&& ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[2] == 0x00
&& ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[3] == 0x00
&& ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[4] == 0x00
&& ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[5] == 0x00)
continue;
memset(sendbuf, 0, BUF_SIZE);
/* Ethernet header */
eh->ether_shost[0] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[0];
eh->ether_shost[1] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[1];
eh->ether_shost[2] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[2];
eh->ether_shost[3] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[3];
eh->ether_shost[4] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[4];
eh->ether_shost[5] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[5];
eh->ether_dhost[0] = 0xff;
eh->ether_dhost[1] = 0xff;
eh->ether_dhost[2] = 0xff;
eh->ether_dhost[3] = 0xff;
eh->ether_dhost[4] = 0xff;
eh->ether_dhost[5] = 0xff;
/* Ethertype field */
eh->ether_type = htons(ETH_P_CUSTOM);
tx_len = sizeof(struct ether_header);
/* Packet data */
sendbuf[tx_len++] = 1;
sendbuf[tx_len++] = op->nHops; //+1;
/* Index of the network device */
socket_address.sll_ifindex = temp->ifIndex;
/* Address length*/
socket_address.sll_halen = ETH_ALEN;
/* Destination MAC */
socket_address.sll_addr[0] = 0xff;
socket_address.sll_addr[1] = 0xff;
socket_address.sll_addr[2] = 0xff;
socket_address.sll_addr[3] = 0xff;
socket_address.sll_addr[4] = 0xff;
socket_address.sll_addr[5] = 0xff;
/* Send packet */
if (sendto(temp->sock, sendbuf, tx_len, 0,
(struct sockaddr*) &socket_address, sizeof(struct sockaddr_ll))
< 0)
printf("Send failed\n");
temp = temp->next;
}
return stat;
}
int announceSelf() {
if (op->upMac[0] == 0x00 && op->upMac[1] == 0x00 && op->upMac[2] == 0x00
&& op->upMac[3] == 0x00 && op->upMac[4] == 0x00
&& op->upMac[5] == 0x00)
return EXIT_SUCCESS;
int stat = 0;
int tx_len = 0;
char sendbuf[BUF_SIZE];
char ifName[IF_NAMESIZE - 1];
struct ether_header *eh = (struct ether_header *) sendbuf;
struct sockaddr_ll socket_address;
int i;
struct ifreq ifr, if_mac;
ifNode * temp = iffirst;
while (temp != NULL) {
memset(&ifr, 0, sizeof(struct ifreq));
ifr.ifr_ifindex = temp->ifIndex;
if (ioctl(temp->sock, SIOCGIFNAME, &ifr) < 0)
perror("SIOCGIFINDEX");
memset(ifName, 0, IF_NAMESIZE - 1);
strncpy(ifName, ifr.ifr_name, IF_NAMESIZE - 1);
/* Get the MAC address of the interface to send on */
memset(&if_mac, 0, sizeof(struct ifreq));
strncpy(if_mac.ifr_name, ifName, IFNAMSIZ - 1);
if (ioctl(temp->sock, SIOCGIFHWADDR, &if_mac) < 0)
perror("SIOCGIFHWADDR");
if (((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[0] == 0x00
&& ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[1] == 0x00
&& ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[2] == 0x00
&& ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[3] == 0x00
&& ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[4] == 0x00
&& ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[5] == 0x00)
continue;
memset(sendbuf, 0, BUF_SIZE);
/* Ethernet header */
eh->ether_shost[0] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[0];
eh->ether_shost[1] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[1];
eh->ether_shost[2] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[2];
eh->ether_shost[3] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[3];
eh->ether_shost[4] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[4];
eh->ether_shost[5] = ((uint8_t *) &if_mac.ifr_hwaddr.sa_data)[5];
eh->ether_dhost[0] = op->upMac[0];
eh->ether_dhost[1] = op->upMac[1];
eh->ether_dhost[2] = op->upMac[2];
eh->ether_dhost[3] = op->upMac[3];
eh->ether_dhost[4] = op->upMac[4];
eh->ether_dhost[5] = op->upMac[5];
/* Ethertype field */
eh->ether_type = htons(ETH_P_CUSTOM);
tx_len = sizeof(struct ether_header);
/* Packet data */
sendbuf[tx_len++] = 2;
sendbuf[tx_len++] = counter();
Node *temp1 = first;
for (; temp1 != NULL; temp1 = temp1->next) {
sendbuf[tx_len++] = temp1->session;
}
socket_address.sll_ifindex = temp->ifIndex;
/* Address length*/
socket_address.sll_halen = ETH_ALEN;
/* Destination MAC */
socket_address.sll_addr[0] = op->upMac[0];
socket_address.sll_addr[1] = op->upMac[1];
socket_address.sll_addr[2] = op->upMac[2];
socket_address.sll_addr[3] = op->upMac[3];
socket_address.sll_addr[4] = op->upMac[4];
socket_address.sll_addr[5] = op->upMac[5];
/* Send packet */
if (sendto(temp->sock, sendbuf, tx_len, 0,
(struct sockaddr*) &socket_address, sizeof(struct sockaddr_ll))
< 0)
printf("Send failed\n");
temp = temp->next;
}
return stat;
}
So to test this you can have VM with linux connected like this (for example):
Provider ----- Node ----- Node ----- Nodekey
I still had a problem when creating multiple sessions, i wasn't incrementing the buffer when reading and I was reading multiple times the same position. Now it's working good
OK, let's begin with the easiest recommendations but I'm not sure this is going to resolve the problem at once. I did a system like this many years ago for different boards with different processor architectures communicating with each other. All the boards were running within a telecommunication switch. It's a very nice problem and you are facing it in the proper way with a peer-to-peer distributed solution.
I didn't go through all code but it seems each node is discovering the neighbour nodes in the network and everyone is creating a tree.
In select, the first argument should not be FD_SETSIZE but the highest-numbered file descriptor in any of the three sets (in this case the read set), plus 1.
The infinite loop is calling receiveSession which is creating all sockets again and then it reads. If a frame with your specific layer-2 protocol arrives in the middle and there is no socket listening for it, it will be discarded. Maybe your problem could be here.
When you send Ethernet frames directly, the hardware will complete the frame to the minimum Ethernet size: 64 octets (so you might receive padding data up to 46 octets - Octets not Bytes)
Please read here:
http://en.wikipedia.org/wiki/Ethernet_frame
It is good you chose an EtherType ETH_P_CUSTOM higher than 1536 that is not already in use but maybe you want to use a much higher number in order to minimize possibilities of collision with other protocols.
Something important. Your testbed now is with VM's which are usually x86 architectures, 64 bits. When you run your software in real devices with different processors, that might not be the situation. This is very important because you might have different architectures with different endianship and different integer size. That will affect the integer numbers you send, especially in ether_header, and the size of your structures. You have to use the the macros ntohs, ntohl, htons, htonl to change between host and network endianship (session is uint64_t). You should send data in network endianship. This is not solving your very current problem but you might have this problem in the future.
I am working on an application that will trigger a UAC prompt in whatever program is opened by ShellExecute.
I can't figure out how to hard-code a path for the ShellExecute to run. As of now this program uses whatever path is in arg[0]. How can I build a string to put in the place of arg[0] on the line sinfo.lpFile = arg[0];?
I am very new so if you can't see why making a string to put in that line will solve my problem then you are most likely right.
#include "stdafx.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <shellapi.h>
#include <process.h>
#include "uac-example.h"
int WINAPI WinMain(HINSTANCE inst, HINSTANCE prevInst,LPSTR cmdLine, int nCmdShow){
LPWSTR *arg;
int argc = 0;
HRESULT ret = SUCCESS;
WCHAR imagePath[MAXPATHLEN];
WCHAR workingDir[MAXPATHLEN];
WCHAR uacDir[MAXPATHLEN];
WCHAR uacRunningLockFilePath[MAXPATHLEN];
HANDLE uacRunningLockFileHandle = INVALID_HANDLE_VALUE;
WCHAR elevatedLockFilePath[MAXPATHLEN];
HANDLE elevatedLockFileHandle = INVALID_HANDLE_VALUE;
arg = CommandLineToArgvW(GetCommandLineW(),&argc);
//if(arg == NULL || argc < 2) {
// ERRORBOX("Missing required program arguments.\n\nUsage:\nuac-example.exe <working directory>");
// return FAILURE;
//}
GetModuleFileName(NULL, imagePath, MAXPATHLEN);
arg[0] = imagePath;
wcscpy_s((wchar_t *)uacDir, MAXPATHLEN, arg[1]);
_snwprintf_s(uacRunningLockFilePath, MAXPATHLEN, MAXPATHLEN,
_T("%s/") _T(RUNNING_LOCK_FILE), uacDir);
wcscpy_s(workingDir, MAXPATHLEN, imagePath);
WCHAR *slash = wcsrchr(workingDir, '\\');
wcscpy_s(slash, MAXPATHLEN, _T(""));
_snwprintf_s(elevatedLockFilePath, MAXPATHLEN, MAXPATHLEN,_T("%s/") _T(ELEVATE_LOCK_FILE), workingDir);
uacRunningLockFileHandle = CreateFileW(uacRunningLockFilePath,(GENERIC_READ | GENERIC_WRITE),0,NULL,OPEN_ALWAYS,FILE_FLAG_DELETE _ON_CLOSE,NULL);
if (uacRunningLockFileHandle == INVALID_HANDLE_VALUE) {
if (_waccess(elevatedLockFilePath, F_OK) == 0 &&
_wremove(elevatedLockFilePath) != 0) {
return FAILURE;
}
elevatedLockFileHandle = CreateFileW(elevatedLockFilePath,(GENERIC_READ | GENERIC_WRITE),0,NULL,OPEN_ALWAYS,FILE_FLAG_DELETE _ON_CLOSE,NULL);
if(elevatedLockFileHandle == INVALID_HANDLE_VALUE){
ERRORBOX("Unable to acquire the necessary permissions to run demo app.");
return FAILURE;
}
LPWSTR spawnCmdLine = BuildCommandLine(argc - 1, arg + 1);
if(!spawnCmdLine){
CloseHandle(elevatedLockFileHandle);
ERRORBOX("An error occured while respawning self.");
return FAILURE;
}
SHELLEXECUTEINFO sinfo;
memset(&sinfo, 0, sizeof(SHELLEXECUTEINFO));
sinfo.cbSize = sizeof(SHELLEXECUTEINFO);
sinfo.fMask = SEE_MASK_FLAG_DDEWAIT | SEE_MASK_NOCLOSEPROCESS;
sinfo.hwnd = NULL;
sinfo.lpFile = arg[0];
sinfo.lpParameters = spawnCmdLine;
sinfo.lpVerb = L"runas"; // <<-- this is what makes a UAC prompt show up
sinfo.nShow = SW_SHOWMAXIMIZED;
BOOL result = ShellExecuteEx(&sinfo);
LocalFree(spawnCmdLine);
if(result){
WaitForSingleObject(sinfo.hProcess, INFINITE);
CloseHandle(sinfo.hProcess);
return SUCCESS;
}else{
return FAILURE;
}
}
EXIT_IF_ELEVATED(elevatedLockFilePath,uacRunningLo ckFileHandle,SUCCESS);
LocalFree(arg);
return SUCCESS;
}
// ----------------------------------------------------------------------
// The following code was taken directly from the Mozilla Firefox Updater
// source tree, and slightly modified to support "Wide" strings in
// Visual C++.
// ----------------------------------------------------------------------
LPWSTR
BuildCommandLine(int argc, LPWSTR *argv){
int i;
int len = 0;
// The + 1 of the last argument handles the
// allocation for null termination
for (i = 0; i < argc; ++i) {
len += ArgStrLen(argv[i]) + 1;
}
// Protect against callers that pass 0 arguments
if (len == 0) {
len = 1;
}
LPWSTR s = (LPWSTR)malloc(len * sizeof(LPWSTR));
if (!s) {
return NULL;
}
LPWSTR c = s;
for (i = 0; i < argc; ++i) {
c = ArgToString(c, argv[i]);
if (i + 1 != argc) {
*c = ' ';
++c;
}
}
*c = '\0';
return s;
}
int
ArgStrLen(LPWSTR s) {
int backslashes = 0;
int i = wcslen(s);
BOOL hasDoubleQuote = wcschr(s, L'"') != NULL;
// Only add doublequotes if the string contains a space or a tab
BOOL addDoubleQuotes = wcspbrk(s, L" \t") != NULL;
if (addDoubleQuotes) {
i += 2; // initial and final duoblequote
}
if (hasDoubleQuote) {
while (*s) {
if (*s == '\\') {
++backslashes;
} else {
if (*s == '"') {
// Escape the doublequote and all backslashes preceding the doublequote
i += backslashes + 1;
}
backslashes = 0;
}
++s;
}
}
return i;
}
LPWSTR
ArgToString(LPWSTR d, LPWSTR s) {
int backslashes = 0;
BOOL hasDoubleQuote = wcschr(s, L'"') != NULL;
// Only add doublequotes if the string contains a space or a tab
BOOL addDoubleQuotes = wcspbrk(s, L" \t") != NULL;
if (addDoubleQuotes) {
*d = '"'; // initial doublequote
++d;
}
if (hasDoubleQuote) {
int i;
while (*s) {
if (*s == '\\') {
++backslashes;
} else {
if (*s == '"') {
// Escape the doublequote and all backslashes\
// preceding the doublequote
for (i = 0; i <= backslashes; ++i) {
*d = '\\';
++d;
}
}
backslashes = 0;
}
*d = *s;
++d; ++s;
}
} else {
wcscpy(d, s);
d += wcslen(s);
}
if (addDoubleQuotes) {
*d = '"'; // final doublequote
++d;
}
return d;
}
Simply as:
char path[] = "C:\\program.exe";
sinfo.lpFile = path;
I have got MAC address as under.
struct ifreq ifr;
struct ifreq *IFR;
struct ifconf ifc;
char buf[1024];
int s, i;
int ok = 0;
string macAddr = "";
s = socket(AF_INET, SOCK_DGRAM, 0);
if (s==-1) {
return;
}
ifc.ifc_len = sizeof(buf);
ifc.ifc_buf = buf;
ioctl(s, SIOCGIFCONF, &ifc);
IFR = ifc.ifc_req;
for (i = ifc.ifc_len / sizeof(struct ifreq); --i >= 0; IFR++) {
strcpy(ifr.ifr_name, IFR->ifr_name);
if (ioctl(s, SIOCGIFFLAGS, &ifr) == 0) {
if (! (ifr.ifr_flags & IFF_LOOPBACK)) {
if (ioctl(s, SIOCGIFHWADDR, &ifr) == 0) {
ok = 1;
break;
}
}
}
}
close(s);
int p = sizeof(ifr.ifr_hwaddr.sa_data);
cout<<"\n Size:"<<p<<"\n";
for(int i = 0; i < p; i++)
macAddr += ifr.ifr_hwaddr.sa_data[i];
cout<<"\n MAC Address:"<<macAddr<<"\n";
I got ifr.ifr_hwaddr.sa_data data proper, but when I print out I am not getting proper value. What can be the issue for it.
The address in sa_data isn't in text form, it's the raw binary form, so you need to format it as hex yourself. You also can't use sizeof to get the size of the address as sa_data is a generically sized array - you need to look at the sa_len member to get the length of this address. In C you want something like this:
char *separator = "";
for (int i = 0; i < ifr.ifr_hwaddr.sa_len; i++)
{
printf("%s%02x", separator, ifr.ifr_hwaddr.sa_data[i]);
separator = ":";
}
printf("\n");