[syslinux:master] com32: add library function for DNS lookup

[syslinux-bot for H. Peter Anvin]

Commit-ID:  7d31294fd5966ba2a8d6e47f663a13d52eae9046
Gitweb:     http://syslinux.zytor.com/commit/7d31294fd5966ba2a8d6e47f663a13d52eae9046
Author:     H. Peter Anvin <hpa at zytor.com>
AuthorDate: Sat, 6 Feb 2010 16:31:26 -0800
Committer:  H. Peter Anvin <hpa at zytor.com>
CommitDate: Sat, 6 Feb 2010 16:31:26 -0800

com32: add library function for DNS lookup

Add a library function for DNS lookup

Signed-off-by: H. Peter Anvin <hpa at zytor.com>


---
 com32/lib/Makefile                              |    1 +
 com32/lib/syslinux/{pxe_get_nic.c => pxe_dns.c} |   31 ++++++++++++++--------
 2 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/com32/lib/Makefile b/com32/lib/Makefile
index ff5887b..9c0a113 100644
--- a/com32/lib/Makefile
+++ b/com32/lib/Makefile
@@ -108,6 +108,7 @@ LIBOBJS = \
 	syslinux/initramfs_archive.o					\
 	\
 	syslinux/pxe_get_cached.o syslinux/pxe_get_nic.o		\
+	syslinux/pxe_dns.o						\
 	\
 	syslinux/adv.o syslinux/advwrite.o syslinux/getadv.o		\
 	syslinux/setadv.o						\
diff --git a/com32/lib/syslinux/pxe_get_nic.c b/com32/lib/syslinux/pxe_dns.c
similarity index 76%
copy from com32/lib/syslinux/pxe_get_nic.c
copy to com32/lib/syslinux/pxe_dns.c
index 704a0d7..9ab9513 100644
--- a/com32/lib/syslinux/pxe_get_nic.c
+++ b/com32/lib/syslinux/pxe_dns.c
@@ -1,6 +1,6 @@
 /* ----------------------------------------------------------------------- *
  *
- *   Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
+ *   Copyright 2010 Intel Corporation; author: H. Peter Anvin
  *
  *   Permission is hereby granted, free of charge, to any person
  *   obtaining a copy of this software and associated documentation
@@ -26,11 +26,12 @@
  * ----------------------------------------------------------------------- */
 
 /*
- * pxe_get_cached.c
+ * pxe_dns.c
  *
- * PXE call "get cached info"
+ * Resolve a hostname via DNS
  */
 
+#include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
@@ -40,22 +41,30 @@
 
 /* Returns the status code from PXE (0 on success),
    or -1 on invocation failure */
-int pxe_get_nic_type(t_PXENV_UNDI_GET_NIC_TYPE * gnt)
+uint32_t pxe_dns(const char *hostname)
 {
     com32sys_t regs;
+    union {
+	unsigned char b[4];
+	uint32_t ip;
+    } q;
+
+    /* Is this a dot-quad? */
+    if (sscanf(hostname, "%hhu.%hhu.%hhu.%hhu",
+	       &q.b[0], &q.b[1], &q.b[2], &q.b[3]) == 4)
+	return q.ip;
 
     memset(&regs, 0, sizeof regs);
-    regs.eax.w[0] = 0x0009;
-    regs.ebx.w[0] = PXENV_UNDI_GET_NIC_TYPE;
+    regs.eax.w[0] = 0x0010;
     regs.es = SEG(__com32.cs_bounce);
-    regs.edi.w[0] = OFFS(__com32.cs_bounce);
+    regs.ebx.w[0] = OFFS(__com32.cs_bounce);
 
-    __intcall(0x22, &regs, &regs);
+    strcpy((char *)__com32.cs_bounce, hostname);
 
-    memcpy(gnt, __com32.cs_bounce, sizeof(t_PXENV_UNDI_GET_NIC_TYPE));
+    __intcall(0x22, &regs, &regs);
 
     if (regs.eflags.l & EFLAGS_CF)
-	return -1;
+	return 0;
 
-    return gnt->Status;
+    return regs.eax.l;
 }