Initial revision

1 files changed, 115 insertions, 0 deletions

diff --git a/mdk-stage1/dietlibc/libcruft/dnscruft.c b/mdk-stage1/dietlibc/libcruft/dnscruft.c
new file mode 100644
index 000000000..d7a0efa50
--- /dev/null
+++ b/mdk-stage1/dietlibc/libcruft/dnscruft.c
@@ -0,0 +1,115 @@
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdlib.h>
+
+int __dns_fd=-1;
+
+void __dns_make_fd() {
+  int tmp;
+  struct sockaddr_in si;
+  if (__dns_fd>0) return;
+  tmp=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP);
+  if (tmp<0) {
+	  perror("__dns_make_fd!socket");
+	  return;
+  }
+  si.sin_family=AF_INET;
+  si.sin_port=0;
+  si.sin_addr.s_addr=INADDR_ANY;
+  if (bind(tmp,(struct sockaddr*)&si,sizeof(si))) {
+	  perror("__dns_make_fd!bind");
+	  return;
+  }
+  __dns_fd=tmp;
+}
+
+int __dns_servers=0;
+struct sockaddr __dns_server_ips[8];
+
+int __dns_search=0;
+char *__dns_domains[8];
+
+void __dns_readstartfiles() {
+  int fd;
+  char *buf=alloca(4096);
+  int len;
+  if (__dns_servers>0) return;
+  {
+    struct sockaddr_in to;
+    char *cacheip=getenv("DNSCACHEIP");
+    if (cacheip) {
+      to.sin_port=htons(53);
+      to.sin_family=AF_INET;
+      if (inet_aton(cacheip,&to.sin_addr)) {
+	memmove(__dns_server_ips,&to,sizeof(struct sockaddr));
+	++__dns_servers;
+      }
+    }
+  }
+  if ((fd=open("/etc/resolv.conf",O_RDONLY))<0) return;
+  len=read(fd,buf,4096);
+  close(fd);
+  {
+    char *last=buf+len;
+    for (; buf<last;) {
+      if (!strncmp(buf,"nameserver",10)) {
+	buf+=10;
+	while (buf<last && *buf!='\n') {
+	  while (buf<last && isblank(*buf)) ++buf;
+	  {
+	    char *tmp=buf;
+	    struct sockaddr_in i;
+	    while (buf<last && !isspace(*buf)) ++buf;
+	    if (buf>=last) break;
+	    *buf=0;
+	    if (inet_aton(tmp,&i.sin_addr)) {
+	      i.sin_family=AF_INET;
+	      i.sin_port=htons(53);
+	      memmove(&__dns_server_ips[__dns_servers],&i,sizeof(struct sockaddr));
+	      if (__dns_servers<8) ++__dns_servers;
+	    }
+	  }
+	}
+      }
+      if (!strncmp(buf,"search",6) || !strncmp(buf,"domain",6)) {
+	buf+=6;
+      }
+      while (buf<last && *buf!='\n') ++buf;
+      while (buf<last && *buf=='\n') ++buf;
+    }
+  }
+}
+
+/* return length of decoded data or -1 */
+int __dns_decodename(unsigned char *packet,int offset,unsigned char *dest,int maxlen) {
+  unsigned char *tmp;
+  unsigned char *max=dest+maxlen;
+  unsigned char *after=packet+offset;
+  int ok=0;
+  for (tmp=after; maxlen>0&&*tmp; ) {
+    if ((*tmp>>6)==3) {		/* goofy DNS decompression */
+      unsigned int ofs=((unsigned int)(*tmp&0x3f)<<8)|*(tmp+1);
+      if (ofs>=offset) return -1;	/* RFC1035: "pointer to a _prior_ occurrance" */
+      if (after<tmp+2) after=tmp+2;
+      tmp=packet+ofs;
+      ok=0;
+    } else {
+      unsigned int duh;
+      if (dest+*tmp+1>max) return -1;
+      for (duh=*tmp; duh>0; --duh)
+	*dest++=*++tmp;
+      *dest++='.'; ok=1;
+      ++tmp;
+      if (tmp>after) { after=tmp; if (!*tmp) ++after; }
+    }
+  }
+  if (ok) --dest;
+  *dest=0;
+  return after-packet;
+}