[syslinux] [PATCH] efi/pxe.c: Allow ipv4 host names

[Lincoln Thurlow]

EFI devices should be allowed to use host names for remote servers.
Only adds ipv4 host name functionality for efi devices.
Reuses core/fs/pxe/dnsresolv.c parse_dotquad code to implement.

Signed-off-by: Lincoln Thurlow <lincoln at isi.edu>
---
  efi/pxe.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
  1 file changed, 49 insertions(+)

diff --git a/efi/pxe.c b/efi/pxe.c
index 5b552b39..366f30fd 100644
--- a/efi/pxe.c
+++ b/efi/pxe.c
@@ -35,8 +35,52 @@ int reset_pxe(void)
  #define DNS_MAX_SERVERS 4        /* Max no of DNS servers */
  uint32_t dns_server[DNS_MAX_SERVERS] = {0, };

+
+/*
+ * parse the ip_str and return the ip address with *res.
+ * return true if the whole string was consumed and the result
+ * was valid.
+ *
+ */
+static bool parse_quad(const char *ip_str, uint32_t *res)
+{
+    const char *p = ip_str;
+    uint8_t part = 0;
+    uint32_t ip = 0;
+    int i;
+
+    for (i = 0; i < 4; i++) {
+        while (is_digit(*p)) {
+            part = part * 10 + *p - '0';
+            p++;
+        }
+        if (i != 3 && *p != '.')
+            return false;
+
+        ip = (ip << 8) | part;
+        part = 0;
+        p++;
+    }
+    p--;
+
+    *res = htonl(ip);
+    return *p == '\0';
+}
+
+
+/*
+ * Similar implementation as core/fs/pxe/dnsresolv.c
+ *
+ * Allow ipv4 host names to be used. Do not support
+ * DNS names or ipv6.
+ *
+ */
+
  __export uint32_t pxe_dns(const char *name)
  {
+
+    uint32_t ip;
+
      /*
       * Return failure on an empty input... this can happen during
       * some types of URL parsing, and this is the easiest place to
@@ -45,6 +89,11 @@ __export uint32_t pxe_dns(const char *name)
      if (!name || !*name)
      return 0;

+    /* If it is a valid dot quad, just return that value */
+    if (parse_quad(name, &ip)){
+        return ip;
+    }
+
      return 0;
  }

-- 
2.17.1