pxe: stop using trackbuf for DHCP packets

Get rid of yet another trackbuf usage.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

3 files changed, 23 insertions, 15 deletions

diff --git a/core/fs/pxe/dhcp_option.c b/core/fs/pxe/dhcp_option.c
index 50f2de04..f63d4a91 100644
--- a/core/fs/pxe/dhcp_option.c
+++ b/core/fs/pxe/dhcp_option.c
@@ -227,12 +227,10 @@ static void parse_dhcp_options(const void *option, int size, uint8_t opt_filter)
  * LocalDomain	- Local domain name
  * MAC_len, MAC	- Client identifier, if MAC_len == 0
  *
- * This assumes the DHCP packet is in "trackbuf".
- *
  */
-void parse_dhcp(int pkt_len)
+void parse_dhcp(const void *pkt, size_t pkt_len)
 {
-    struct bootp_t *dhcp = (struct bootp_t *)trackbuf;
+    const struct bootp_t *dhcp = (const struct bootp_t *)pkt;
     int opt_len;
 
     IPInfo.ipv4 = 4;		/* This is IPv4 only for now... */
diff --git a/core/fs/pxe/pxe.c b/core/fs/pxe/pxe.c
index 7b63d17b..b8156afc 100644
--- a/core/fs/pxe/pxe.c
+++ b/core/fs/pxe/pxe.c
@@ -340,13 +340,13 @@ static void ack_packet(struct inode *inode, uint16_t ack_num)
 
 
 /**
- * Get a DHCP packet from the PXE stack into the trackbuf
+ * Get a DHCP packet from the PXE stack into a lowmem buffer
  *
  * @param:  type,  packet type
  * @return: buffer size
  *
  */
-static int pxe_get_cached_info(int type)
+static int pxe_get_cached_info(int type, char *buf, size_t bufsiz)
 {
     int err;
     static __lowmem struct s_PXENV_GET_CACHED_INFO get_cached_info;
@@ -354,8 +354,8 @@ static int pxe_get_cached_info(int type)
 
     get_cached_info.Status      = 0;
     get_cached_info.PacketType  = type;
-    get_cached_info.BufferSize  = 8192;
-    get_cached_info.Buffer      = FAR_PTR(trackbuf);
+    get_cached_info.BufferSize  = bufsiz;
+    get_cached_info.Buffer      = FAR_PTR(buf);
     err = pxe_call(PXENV_GET_CACHED_INFO, &get_cached_info);
     if (err) {
         printf("PXE API call failed, error  %04x\n", err);
@@ -1450,6 +1450,14 @@ static void network_init(void)
 {
     struct bootp_t *bp = (struct bootp_t *)trackbuf;
     int pkt_len;
+    char *dhcp_packet;
+    const size_t dhcp_max_packet = 4096;
+
+    dhcp_packet = lmalloc(dhcp_max_packet);
+    if (!dhcp_packet) {
+	printf("Out of low memory\n");
+	kaboom();
+    }
 
     *LocalDomain = 0;   /* No LocalDomain received */
 
@@ -1457,8 +1465,8 @@ static void network_init(void)
      * Get the DHCP client identifiers (query info 1)
      */
     printf("Getting cached packet ");
-    pkt_len = pxe_get_cached_info(1);
-    parse_dhcp(pkt_len);
+    pkt_len = pxe_get_cached_info(1, dhcp_packet, dhcp_max_packet);
+    parse_dhcp(dhcp_packet, pkt_len);
     /*
      * We don't use flags from the request packet, so
      * this is a good time to initialize DHCPMagic...
@@ -1474,8 +1482,8 @@ static void network_init(void)
      * Get the BOOTP/DHCP packet that brought us file (and an IP
      * address). This lives in the DHCPACK packet (query info 2)
      */
-    pkt_len = pxe_get_cached_info(2);
-    parse_dhcp(pkt_len);
+    pkt_len = pxe_get_cached_info(2, dhcp_packet, dhcp_max_packet);
+    parse_dhcp(dhcp_packet, pkt_len);
     /*
      * Save away MAC address (assume this is in query info 2. If this
      * turns out to be problematic it might be better getting it from
@@ -1489,10 +1497,12 @@ static void network_init(void)
      * Get the boot file and other info. This lives in the CACHED_REPLY
      * packet (query info 3)
      */
-    pkt_len = pxe_get_cached_info(3);
-    parse_dhcp(pkt_len);
+    pkt_len = pxe_get_cached_info(3, dhcp_packet, dhcp_max_packet);
+    parse_dhcp(dhcp_packet, pkt_len);
     printf("\n");
 
+    lfree(dhcp_packet);
+
     make_bootif_string();
     make_sysuuid_string();
     ip_init();
diff --git a/core/fs/pxe/pxe.h b/core/fs/pxe/pxe.h
index 1e6fa76a..47ed8f06 100644
--- a/core/fs/pxe/pxe.h
+++ b/core/fs/pxe/pxe.h
@@ -235,7 +235,7 @@ bool ip_ok(uint32_t);
 int pxe_call(int, void *);
 
 /* dhcp_options.c */
-void parse_dhcp(int);
+void parse_dhcp(const void *, size_t);
 
 /* dnsresolv.c */
 int dns_mangle(char **, const char *);