slirp: Implement RFC2132 TFTP server name

This new usernet option can be used to add data for option 66 (tftp
server name) in the BOOTP reply, which is useful in PXE based automatic
OS install such as OpenBSD.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

5 files changed, 18 insertions, 0 deletions

diff --git a/slirp/bootp.c b/slirp/bootp.c
index 1e8185f..7b1af73 100644
--- a/slirp/bootp.c
+++ b/slirp/bootp.c
@@ -318,6 +318,19 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
             }
         }
 
+        if (slirp->tftp_server_name) {
+            val = strlen(slirp->tftp_server_name);
+            if (q + val + 2 >= end) {
+                g_warning("DHCP packet size exceeded, "
+                    "omitting tftp-server-name option.");
+            } else {
+                *q++ = RFC2132_TFTP_SERVER_NAME;
+                *q++ = val;
+                memcpy(q, slirp->tftp_server_name, val);
+                q += val;
+            }
+        }
+
         if (slirp->vdnssearch) {
             val = slirp->vdnssearch_len;
             if (q + val >= end) {
diff --git a/slirp/bootp.h b/slirp/bootp.h
index 3945257..4043489 100644
--- a/slirp/bootp.h
+++ b/slirp/bootp.h
@@ -70,6 +70,7 @@
 #define RFC2132_MAX_SIZE	57
 #define RFC2132_RENEWAL_TIME    58
 #define RFC2132_REBIND_TIME     59
+#define RFC2132_TFTP_SERVER_NAME 66
 
 #define DHCPDISCOVER		1
 #define DHCPOFFER		2
diff --git a/slirp/libslirp.h b/slirp/libslirp.h
index 740408a..42e42e9 100644
--- a/slirp/libslirp.h
+++ b/slirp/libslirp.h
@@ -13,6 +13,7 @@ Slirp *slirp_init(int restricted, bool in_enabled, struct in_addr vnetwork,
                   bool in6_enabled,
                   struct in6_addr vprefix_addr6, uint8_t vprefix_len,
                   struct in6_addr vhost6, const char *vhostname,
+                  const char *tftp_server_name,
                   const char *tftp_path, const char *bootfile,
                   struct in_addr vdhcp_start, struct in_addr vnameserver,
                   struct in6_addr vnameserver6, const char **vdnssearch,
diff --git a/slirp/slirp.c b/slirp/slirp.c
index 5c3bd61..51de41f 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -283,6 +283,7 @@ Slirp *slirp_init(int restricted, bool in_enabled, struct in_addr vnetwork,
                   bool in6_enabled,
                   struct in6_addr vprefix_addr6, uint8_t vprefix_len,
                   struct in6_addr vhost6, const char *vhostname,
+                  const char *tftp_server_name,
                   const char *tftp_path, const char *bootfile,
                   struct in_addr vdhcp_start, struct in_addr vnameserver,
                   struct in6_addr vnameserver6, const char **vdnssearch,
@@ -321,6 +322,7 @@ Slirp *slirp_init(int restricted, bool in_enabled, struct in_addr vnetwork,
     slirp->vdhcp_startaddr = vdhcp_start;
     slirp->vnameserver_addr = vnameserver;
     slirp->vnameserver_addr6 = vnameserver6;
+    slirp->tftp_server_name = g_strdup(tftp_server_name);
 
     if (vdnssearch) {
         translate_dnssearch(slirp, vdnssearch);
diff --git a/slirp/slirp.h b/slirp/slirp.h
index 10b4108..b80725a 100644
--- a/slirp/slirp.h
+++ b/slirp/slirp.h
@@ -212,6 +212,7 @@ struct Slirp {
     /* tftp states */
     char *tftp_prefix;
     struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX];
+    char *tftp_server_name;
 
     ArpTable arp_table;
     NdpTable ndp_table;