Do the check for a valid direction value in pcap_setdirection().

That way, we don't have to do the check in the individual setdirection
op routines.

pcap-bpf.c

@@ -3283,18 +3283,18 @@ pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d)
 		direction_name = "\"outgoing only\"";
 		break;
 
-	case PCAP_D_INOUT:
+	default:
 		/*
 		 * Incoming and outgoing, so accept both
 		 * incoming and outgoing packets.
+		 *
+		 * It's guaranteed, at this point, that d is a valid
+		 * direction value, so we know that this is PCAP_D_INOUT
+		 * if it's not PCAP_D_IN or PCAP_D_OUT.
 		 */
 		direction = BPF_D_INOUT;
 		direction_name = "\"incoming and outgoing\"";
 		break;
-
-	default:
-		snprintf(p->errbuf, sizeof(p->errbuf), "Invalid direction");
-		return (-1);
 	}
 
 	if (ioctl(p->fd, BIOCSDIRECTION, &direction) == -1) {
@@ -3337,18 +3337,18 @@ pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d)
 		direction_name = "\"outgoing only\"";
 		break;
 
-	case PCAP_D_INOUT:
+	default:
 		/*
 		 * Incoming and outgoing, so don't filter out
 		 * any packets based on direction.
+		 *
+		 * It's guaranteed, at this point, that d is a valid
+		 * direction value, so we know that this is PCAP_D_INOUT
+		 * if it's not PCAP_D_IN or PCAP_D_OUT.
 		 */
 		dirfilt = 0;
 		direction_name = "\"incoming and outgoing\"";
 		break;
-
-	default:
-		snprintf(p->errbuf, sizeof(p->errbuf), "Invalid direction");
-		return (-1);
 	}
 	if (ioctl(p->fd, BIOCSDIRFILT, &dirfilt) == -1) {
 		pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
@@ -3386,18 +3386,18 @@ pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d)
 		    "Setting direction to \"outgoing only\" is not supported on this device");
 		return (-1);
 
-	case PCAP_D_INOUT:
+	default:
 		/*
 		 * Incoming and outgoing, so we want to see transmitted
 		 * packets.
+		 *
+		 * It's guaranteed, at this point, that d is a valid
+		 * direction value, so we know that this is PCAP_D_INOUT
+		 * if it's not PCAP_D_IN or PCAP_D_OUT.
 		 */
 		seesent = 1;
 		direction_name = "\"incoming and outgoing\"";
 		break;
-
-	default:
-		snprintf(p->errbuf, sizeof(p->errbuf), "Invalid direction");
-		return (-1);
 	}
 
 	if (ioctl(p->fd, BIOCSSEESENT, &seesent) == -1) {

pcap-bt-linux.c

@@ -430,17 +430,10 @@ bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 static int
 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 {
-	switch (d) {
-
-	case PCAP_D_IN:
-	case PCAP_D_OUT:
-	case PCAP_D_INOUT:
-		p->direction = d;
-		break;
-
-	default:
-		snprintf(p->errbuf, sizeof(p->errbuf), "Invalid direction");
-		return (-1);
-	}
+	/*
+	 * It's guaranteed, at this point, that d is a valid
+	 * direction value.
+	 */
+	p->direction = d;
 	return 0;
 }

pcap-linux.c

@@ -2610,19 +2610,11 @@ pcap_setfilter_linux(pcap_t *handle, struct bpf_program *filter)
 static int
 pcap_setdirection_linux(pcap_t *handle, pcap_direction_t d)
 {
-	switch (d) {
-
-	case PCAP_D_IN:
-	case PCAP_D_OUT:
-	case PCAP_D_INOUT:
-		handle->direction = d;
-		break;
-
-	default:
-		snprintf(handle->errbuf, sizeof(handle->errbuf),
-		    "Invalid direction");
-		return -1;
-	}
+	/*
+	 * It's guaranteed, at this point, that d is a valid
+	 * direction value.
+	 */
+	handle->direction = d;
 	return 0;
 }
 

pcap-usb-linux.c

@@ -1109,18 +1109,11 @@ usb_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 static int
 usb_setdirection_linux(pcap_t *p, pcap_direction_t d)
 {
-	switch (d) {
-
-	case PCAP_D_IN:
-	case PCAP_D_OUT:
-	case PCAP_D_INOUT:
-		p->direction = d;
-		break;
-
-	default:
-		snprintf(p->errbuf, sizeof(p->errbuf), "Invalid direction");
-		return -1;
-	}
+	/*
+	 * It's guaranteed, at this point, that d is a valid
+	 * direction value.
+	 */
+	p->direction = d;
 	return 0;
 }
 

pcap.c

@@ -3533,8 +3533,26 @@ pcap_setdirection(pcap_t *p, pcap_direction_t d)
 		snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 		    "Setting direction is not supported on this device");
 		return (-1);
-	} else
-		return (p->setdirection_op(p, d));
+	} else {
+		switch (d) {
+
+		case PCAP_D_IN:
+		case PCAP_D_OUT:
+		case PCAP_D_INOUT:
+			/*
+			 * Valid direction.
+			 */
+			return (p->setdirection_op(p, d));
+
+		default:
+			/*
+			 * Invalid direction.
+			 */
+			snprintf(p->errbuf, sizeof(p->errbuf),
+			    "Invalid direction");
+			return (-1);
+		}
+	}	
 }
 
 int