From: Denis Ovsienko <denis@ovsienko.info>
Date: Fri, 21 Mar 2025 12:34:10 +0000 (+0000)
Subject: Factor fail_kw_on_dlt() out.
X-Git-Url: https://git.tcpdump.org/libpcap/commitdiff_plain/c26a0aa6709490e1670edb3f0f7f2572c9f38031

Factor fail_kw_on_dlt() out.

Replace seven hard-coded error messages with one parametrised message.
---

diff --git a/gencode.c b/gencode.c
index 167e0051..57652be9 100644
--- a/gencode.c
+++ b/gencode.c
@@ -857,6 +857,13 @@ syntax(compiler_state_t *cstate)
 	bpf_error(cstate, "syntax error in filter expression");
 }
 
+static PCAP_NORETURN_DEF void
+fail_kw_on_dlt(compiler_state_t *cstate, const char *keyword)
+{
+	bpf_error(cstate, "'%s' not supported on %s", keyword,
+	    pcap_datalink_val_to_description_or_dlt(cstate->linktype));
+}
+
 int
 pcap_compile(pcap_t *p, struct bpf_program *program,
 	     const char *buf, int optimize, bpf_u_int32 mask)
@@ -3865,8 +3872,7 @@ gen_llc_internal(compiler_state_t *cstate)
 			IEEE80211_FC0_TYPE_MASK);
 
 	default:
-		bpf_error(cstate, "'llc' not supported for %s",
-			  pcap_datalink_val_to_description_or_dlt(cstate->linktype));
+		fail_kw_on_dlt(cstate, "llc");
 		/*NOTREACHED*/
 	}
 }
@@ -8363,9 +8369,8 @@ gen_broadcast(compiler_state_t *cstate, int proto)
 			return gen_wlanhostop(cstate, ebroadcast, Q_DST);
 		case DLT_IP_OVER_FC:
 			return gen_ipfchostop(cstate, ebroadcast, Q_DST);
-		default:
-			bpf_error(cstate, "not a broadcast link");
 		}
+		fail_kw_on_dlt(cstate, "broadcast");
 		/*NOTREACHED*/
 
 	case Q_IP:
@@ -8571,8 +8576,8 @@ gen_multicast(compiler_state_t *cstate, int proto)
 		default:
 			break;
 		}
-		/* Link not known to support multicasts */
-		break;
+		fail_kw_on_dlt(cstate, "multicast");
+		/*NOTREACHED*/
 
 	case Q_IP:
 		b0 = gen_linktype(cstate, ETHERTYPE_IP);
@@ -8636,8 +8641,7 @@ gen_ifindex(compiler_state_t *cstate, int ifindex)
 		b0 = gen_cmp(cstate, OR_LINKHDR, SKF_AD_OFF + SKF_AD_IFINDEX, BPF_W,
 		             ifindex);
 #else /* defined(__linux__) */
-		bpf_error(cstate, "ifindex not supported on %s",
-		    pcap_datalink_val_to_description_or_dlt(cstate->linktype));
+		fail_kw_on_dlt(cstate, "ifindex");
 		/*NOTREACHED*/
 #endif /* defined(__linux__) */
 	}
@@ -8759,8 +8763,7 @@ gen_inbound_outbound(compiler_state_t *cstate, const int outbound)
 			gen_not(b0);
 		}
 #else /* defined(__linux__) */
-		bpf_error(cstate, "inbound/outbound not supported on %s",
-		    pcap_datalink_val_to_description_or_dlt(cstate->linktype));
+		fail_kw_on_dlt(cstate, outbound ? "outbound" : "inbound");
 		/*NOTREACHED*/
 #endif /* defined(__linux__) */
 	}
@@ -8942,7 +8945,7 @@ gen_p80211_type(compiler_state_t *cstate, bpf_u_int32 type, bpf_u_int32 mask)
 		break;
 
 	default:
-		bpf_error(cstate, "802.11 link-layer types supported only on 802.11");
+		fail_kw_on_dlt(cstate, "type/subtype");
 		/*NOTREACHED*/
 	}
 
@@ -8971,7 +8974,7 @@ gen_p80211_fcdir(compiler_state_t *cstate, bpf_u_int32 fcdir)
 		break;
 
 	default:
-		bpf_error(cstate, "frame direction supported only with 802.11 headers");
+		fail_kw_on_dlt(cstate, "dir");
 		/*NOTREACHED*/
 	}
 
diff --git a/testprogs/TESTrun b/testprogs/TESTrun
index 73301806..b289366b 100755
--- a/testprogs/TESTrun
+++ b/testprogs/TESTrun
@@ -10983,7 +10983,7 @@ my @reject_tests = (
 		name => 'wlan_on_eth',
 		DLT => 'EN10MB',
 		expr => 'type data',
-		errstr => '802.11 link-layer types supported only on 802.11',
+		errstr => '\'type/subtype\' not supported on Ethernet',
 	},
 	{
 		name => 'wlan_type',
@@ -11059,13 +11059,13 @@ my @reject_tests = (
 		name => 'broadcast_not_supported',
 		DLT => 'SLIP',
 		expr => 'broadcast',
-		errstr => 'not a broadcast link',
+		errstr => '\'broadcast\' not supported on SLIP',
 	},
 	{
 		name => 'multicast_not_supported',
 		DLT => 'SLIP',
 		expr => 'multicast',
-		errstr => 'link-layer multicast filters supported only on',
+		errstr => '\'multicast\' not supported on SLIP',
 	},
 # This test has been flaky because it depends on an external effect (DNS
 # lookup), which sometimes times out.  Let's disable it until there is a good