text_import: Allow fake IP headers with Raw IP encapsulation

In text2pcap and Import from Hex Dump, allow fake IP headers with
the appropriate versions when the Raw IP, Raw IPv4, and Raw IPv6
encapsulations are specified. In such cases, do not add a dummy
Ethernet header.

Continue to reject other encapsulations besides these, Ethernet,
and Wireshark Upper PDU when appropriate. Add some checks for the
encapsulation type in text_import as well, instead of just assuming
that the callers handle it correctly.

1 files changed, 45 insertions, 24 deletions

diff --git a/text2pcap.c b/text2pcap.c
index e1e45eafe7..627cbef61a 100644
--- a/text2pcap.c
+++ b/text2pcap.c
@@ -230,7 +230,8 @@ print_usage (FILE *output)
             "                         Example: -e 0x806 to specify an ARP packet.\n"
             "  -i <proto>             prepend dummy IP header with specified IP protocol\n"
             "                         (in DECIMAL).\n"
-            "                         Automatically prepends Ethernet header as well.\n"
+            "                         Automatically prepends Ethernet header as well if\n"
+            "                         link-layer type is Ethernet.\n"
             "                         Example: -i 46\n"
             "  -4 <srcip>,<destip>    prepend dummy IPv4 header with specified\n"
             "                         dest and source address.\n"
@@ -256,7 +257,6 @@ print_usage (FILE *output)
             "                         Automatically prepends a dummy SCTP DATA\n"
             "                         chunk header with payload protocol identifier ppi.\n"
             "                         Example: -S 30,40,34\n"
-            "\n"
             "  -P <dissector>         prepend EXPORTED_PDU header with specifieddissector\n"
             "                         as the payload PROTO_NAME tag.\n"
             "                         Automatically sets link type to Upper PDU Export.\n"
@@ -278,11 +278,6 @@ print_usage (FILE *output)
  * Set the hdr_ip_proto parameter, and set the flag indicate that the
  * parameter has been specified.
  *
- * Also indicate that we should add an Ethernet link-layer header.
- * (That's not an *inherent* requirement, as we could write a file
- * with a "raw IP packet" link-layer type, meaning that there *is*
- * no link-layer header, but it's the way text2pcap currently works.)
- *
  * XXX - catch the case where two different options set it differently?
  */
 static void
@@ -290,7 +285,6 @@ set_hdr_ip_proto(guint8 ip_proto)
 {
     have_hdr_ip_proto = TRUE;
     hdr_ip_proto = ip_proto;
-    hdr_ethernet = TRUE;
 }
 
 static void
@@ -695,15 +689,6 @@ parse_options(int argc, char *argv[], text_import_info_t * const info, wtap_dump
             return INVALID_OPTION;
         }
     }
-    if (pcap_link_type != 1 && hdr_ethernet) {
-        cmdarg_err("Dummy headers (-e, -i, -u, -s, -S -T) cannot be specified with link type override (-l)");
-        return INVALID_OPTION;
-    }
-
-    if (pcap_link_type != 252 && hdr_export_pdu) {
-        cmdarg_err("Export PDU (-P) requires WIRESHARK_UPPER_PDU link type (252)");
-        return INVALID_OPTION;
-    }
 
     if (have_hdr_ip_proto && !(hdr_ip || hdr_ipv6)) {
         /*
@@ -727,12 +712,49 @@ parse_options(int argc, char *argv[], text_import_info_t * const info, wtap_dump
         hdr_ip = TRUE;
     }
 
-    if (hdr_ip)
-    {
-        hdr_ethernet_proto = 0x0800;
-    } else if (hdr_ipv6)
-    {
-        hdr_ethernet_proto = 0x86DD;
+    wtap_encap_type = wtap_pcap_encap_to_wtap_encap(pcap_link_type);
+
+    if (hdr_export_pdu && wtap_encap_type != WTAP_ENCAP_WIRESHARK_UPPER_PDU) {
+        cmdarg_err("Export PDU (-P) requires WIRESHARK_UPPER_PDU link type (252)");
+        return INVALID_OPTION;
+    }
+
+    /* The other dummy headers require a IPv4 or IPv6 header. Allow
+     * encapsulation types of Ethernet (and add a Ethernet header in that
+     * case if we haven't already), or the appropriate raw IP types.
+     */
+    if (hdr_ip) {
+        switch (wtap_encap_type) {
+
+        case (WTAP_ENCAP_ETHERNET):
+            hdr_ethernet = TRUE;
+            hdr_ethernet_proto = 0x0800;
+            break;
+
+        case (WTAP_ENCAP_RAW_IP):
+        case (WTAP_ENCAP_RAW_IP4):
+            break;
+
+        default:
+            cmdarg_err("Dummy IPv4 header not supported with encapsulation %s (%s)", wtap_encap_description(wtap_encap_type), wtap_encap_name(wtap_encap_type));
+            return INVALID_OPTION;
+        }
+    } else if (hdr_ipv6) {
+        switch (wtap_encap_type) {
+
+        case (WTAP_ENCAP_ETHERNET):
+            hdr_ethernet = TRUE;
+            hdr_ethernet_proto = 0x86DD;
+            break;
+
+        case (WTAP_ENCAP_RAW_IP):
+        case (WTAP_ENCAP_RAW_IP6):
+            break;
+
+        default:
+            cmdarg_err("Dummy IPv6 header not supported with encapsulation %s (%s)", wtap_encap_description(wtap_encap_type), wtap_encap_name(wtap_encap_type));
+            return INVALID_OPTION;
+        }
     }
 
     if (strcmp(argv[ws_optind], "-") != 0) {
@@ -773,7 +795,6 @@ parse_options(int argc, char *argv[], text_import_info_t * const info, wtap_dump
 
     wtap_dump_params_init(params, NULL);
 
-    wtap_encap_type = wtap_pcap_encap_to_wtap_encap(pcap_link_type);
     params->encap = wtap_encap_type;
     params->snaplen = max_offset;
     if (file_type_subtype == WTAP_FILE_TYPE_SUBTYPE_UNKNOWN) {