mirror of
https://github.com/wiidev/usbloadergx.git
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![giantpune](/assets/img/avatar_default.png)
formatted the code to make it easier to read. no functional changes at all. i didn't put anything from the libwiigui folder or banner folder in the beautifier. my automated .bat seems to have done a good job. the only places i see it fucked up was on (GXColor){blablabla}. it treated the brackets in the color like all the other brackets and put the color on a new line and indented it. i think i fixed most of them. not sure if it messed up anywhere else. also not sure about how it handled different linebreaks. it looks fine on windows. if it looks messed up on linux, it can be reverted. the code still compiles and runs fine.
114 lines
3.3 KiB
C
114 lines
3.3 KiB
C
#include "dns.h"
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/**
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* Resolves a domainname to an ip address
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* It makes use of net_gethostbyname from libogc, which in turn makes use of a Wii BIOS function
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* Just like the net_gethostbyname function this function is NOT threadsafe!
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*
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* @param char* The domain name to resolve
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* @return u32 The ipaddress represented by four bytes inside an u32 (in network order)
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*/
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u32 getipbyname(char *domain) {
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//Care should be taken when using net_gethostbyname,
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//it returns a static buffer which makes it not threadsafe
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//TODO: implement some locking mechanism to make below code atomic
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struct hostent *host = net_gethostbyname(domain);
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if (host == NULL) {
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return 0;
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}
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u32 *ip = (u32*)host->h_addr_list[0];
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return *ip;
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}
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//Defines how many DNS entries should be cached by getipbynamecached()
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#define MAX_DNS_CACHE_ENTRIES 20
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//The cache is defined as a linked list,
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//The last resolved domain name will always be at the front
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//This will allow heavily used domainnames to always stay cached
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struct dnsentry {
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char *domain;
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u32 ip;
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struct dnsentry *nextnode;
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} ;
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static struct dnsentry *firstdnsentry = NULL;
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static int dnsentrycount = 0;
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/**
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* Performs the same function as getipbyname(),
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* except that it will prevent extremely expensive net_gethostbyname() calls by caching the result
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*/
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u32 getipbynamecached(char *domain) {
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//Search if this domainname is already cached
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struct dnsentry *node = firstdnsentry;
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struct dnsentry *previousnode = NULL;
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while (node != NULL) {
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if (strcmp(node->domain, domain) == 0) {
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//DNS node found in the cache, move it to the front of the list
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if (previousnode != NULL)
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previousnode->nextnode = node->nextnode;
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if (node != firstdnsentry)
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node->nextnode = firstdnsentry;
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firstdnsentry = node;
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return node->ip;
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}
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//Go to the next element in the list
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previousnode = node;
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node = node->nextnode;
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}
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u32 ip = getipbyname(domain);
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//No cache of this domain could be found, create a cache node and add it to the front of the cache
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struct dnsentry *newnode = malloc(sizeof(struct dnsentry));
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if (newnode == NULL) {
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return ip;
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}
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newnode->ip = ip;
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newnode->domain = malloc(strlen(domain)+1);
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if (newnode->domain == NULL) {
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free(newnode);
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return ip;
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}
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strcpy(newnode->domain, domain);
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newnode->nextnode = firstdnsentry;
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firstdnsentry = newnode;
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dnsentrycount++;
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//If the cache grows too big delete the last (and probably least important) node of the list
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if (dnsentrycount > MAX_DNS_CACHE_ENTRIES) {
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struct dnsentry *node = firstdnsentry;
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struct dnsentry *previousnode = NULL;
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//Fetch the last two elements of the list
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while (node->nextnode != NULL) {
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previousnode = node;
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node = node->nextnode;
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}
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if (node == NULL) {
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printf("Configuration error, MAX_DNS_ENTRIES reached while the list is empty\n");
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exit(1);
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} else if (previousnode == NULL) {
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firstdnsentry = NULL;
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} else {
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previousnode->nextnode = NULL;
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}
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free(node->domain);
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free(node);
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dnsentrycount--;
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}
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return newnode->ip;
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}
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