Have separate "find device" and "find or add device" routines.

Use the "find device" routine for CSPi's Myricom adapters; those
adapters can appear as regular network interfaces, but, when we
enumerate the Myricom adapters, we want to update the description for
those adapters, rather than adding separate entries for them.  While
we're at it, add comments to packet-snf.c explaining this.

Fix some comments and some indentation while we're at it.

1 files changed, 67 insertions, 127 deletions

diff --git a/pcap-snf.c b/pcap-snf.c
index d914a5e7..1679d4df 100644
--- a/pcap-snf.c
+++ b/pcap-snf.c
@@ -321,11 +321,11 @@ snf_activate(pcap_t* p)
 int
 snf_findalldevs(pcap_if_t **devlistp, char *errbuf)
 {
-	pcap_if_t *devlist = NULL,*curdev,*prevdev,*nextdev;
-	pcap_addr_t *curaddr;
+	pcap_if_t *dev;
 	struct snf_ifaddrs *ifaddrs, *ifa;
+	char name[MAX_DESC_LENGTH];
 	char desc[MAX_DESC_LENGTH];
-	int ret, found, allports = 0, merge = 0;
+	int ret, allports = 0, merge = 0;
 	const char *nr = NULL;
 
 	if (snf_init(SNF_VERSION_API)) {
@@ -351,88 +351,72 @@ snf_findalldevs(pcap_if_t **devlistp, char *errbuf)
 	}
 
 	for (ifa = ifaddrs; ifa != NULL; ifa = ifa->snf_ifa_next) {
-		found = 0;
-		nextdev = *devlistp;
 		/*
- 		 * Is there already a device with this name in the list
- 		 * of devices?
+		 * Myricom SNF adapter ports may appear as regular
+		 * network interfaces, which would already have been
+		 * added to the list of adapters by pcap_platform_finddevs()
+		 * if this isn't an SNF-only version of libpcap.
+		 *
+		 * Our create routine intercepts pcap_create() calls for
+		 * those interfaces and arranges that they will be
+		 * opened using the SNF API instead.
+		 *
+		 * So if we already have an entry for the device, we
+		 * don't add an additional entry for it, we just
+		 * update the description for it, if any, to indicate
+		 * which snfN device it is.  Otherwise, we add an entry
+		 * for it.
+		 *
+		 * In either case, if SNF_F_AGGREGATE_PORTMASK is set
+		 * in SNF_FLAGS, we add this port to the bitmask
+		 * of ports, which we use to generate a device
+		 * we can use to capture on all ports.
+		 *
+		 * Generate the description string.  If port aggregation
+		 * is set, use 2^{port number} as the unit number,
+		 * rather than {port number}.
+		 *
+		 * XXX - do entries in this list have IP addresses for
+		 * the port?  If so, should we add them to the
+		 * entry for the device, if they're not already in the
+		 * list of IP addresses for the device?
  		 */
-		while (nextdev != NULL) {
-			if (strcmp(nextdev->name,ifa->snf_ifa_name) == 0) {
-				/*
-				 * Yes.  Update the description for the
-				 * device.
-				 * If port aggregation is set, unit is
-				 * power of 2
-				 */
-				char *desc_str;
-
-				(void)pcap_snprintf(desc,MAX_DESC_LENGTH,"Myricom %ssnf%d",
-					merge ? "Merge Bitmask Port " : "",
-					merge ? 1 << ifa->snf_ifa_portnum : ifa->snf_ifa_portnum);
-				if (merge)
-					allports |= 1 << ifa->snf_ifa_portnum;
-				desc_str = strdup(desc);
-				if (desc_str == NULL) {
-					(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
-					    "snf_findalldevs strdup: %s", pcap_strerror(errno));
-					return (-1);
-				}
-				free(nextdev->description);
-				nextdev->description = desc_str;
-				found = 1;
-				break;
-			}
-			nextdev = nextdev->next;
-		}
-		if (!found) {
-			/*
-			 * Allocate a new entry
-			 */
-			curdev = (pcap_if_t *)malloc(sizeof(pcap_if_t));
-			if (curdev == NULL) {
-				(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
-				    "snf_findalldevs malloc: %s", pcap_strerror(errno));
-				return (-1);
-			}
-			if (devlist == NULL) /* save first entry */
-				devlist = curdev;
-			else
-				prevdev->next = curdev;
+		(void)pcap_snprintf(desc,MAX_DESC_LENGTH,"Myricom %ssnf%d",
+			merge ? "Merge Bitmask Port " : "",
+			merge ? 1 << ifa->snf_ifa_portnum : ifa->snf_ifa_portnum);
+		/*
+		 * Add the port to the bitmask.
+		 */
+		if (merge)
+			allports |= 1 << ifa->snf_ifa_portnum;
+		/*
+		 * See if there's already an entry for the device
+		 * with the name ifa->snf_ifa_name.
+		 */
+		dev = find_dev(alldevs, ifa->snf_ifa_name);
+		if (dev != NULL) {
 			/*
-			 * Fill in the entry.
+			 * Yes.  Update its description.
 			 */
-			curdev->next = NULL;
-			curdev->name = strdup(ifa->snf_ifa_name);
-			if (curdev->name == NULL) {
+			char *desc_str;
+
+			desc_str = strdup(desc);
+			if (desc_str == NULL) {
 				(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
 				    "snf_findalldevs strdup: %s", pcap_strerror(errno));
-				free(curdev);
-				return (-1);
-			}
-			(void)pcap_snprintf(desc,MAX_DESC_LENGTH,"Myricom %ssnf%d",
-				merge ? "Merge Bitmask Port " : "",
-				merge ? 1 << ifa->snf_ifa_portnum : ifa->snf_ifa_portnum);
-			if (merge)
-				allports |= 1 << ifa->snf_ifa_portnum;
-			curdev->description = strdup(desc);
-			if (curdev->description == NULL) {
-				(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
-				    "snf_findalldevs strdup1: %s", pcap_strerror(errno));
-				free(curdev->name);
-				free(curdev);
-				return (-1);
+				return -1;
 			}
-			curdev->addresses = NULL;
-			curdev->flags = 0;
-
+			free(dev->description);
+			dev->description = desc_str;
+		} else {
 			/*
-			 * XXX - are there any actual IP addresses for
-			 * these devices?
+			 * No.  Add an entry for it.
 			 */
-
-			prevdev = curdev;
-		} // end of if entry !found
+			dev = add_dev(alldevs, ifa->snf_ifa_name, 0, desc,
+			    errbuf);
+			if (dev == NULL)
+				return -1;
+		}
 	}
 	snf_freeifaddrs(ifaddrs);
 	/*
@@ -440,62 +424,18 @@ snf_findalldevs(pcap_if_t **devlistp, char *errbuf)
        	 */
 	if (merge) {
 		/*
-		 * Allocate a new entry with all ports bitmask
+		 * Add a new entry with all ports bitmask
 		 */
-		curdev = (pcap_if_t *)malloc(sizeof(pcap_if_t));
-		if (curdev == NULL) {
-			(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
-			    "snf_findalldevs malloc: %s", pcap_strerror(errno));
-			return (-1);
-		}
-		if (devlist == NULL) /* save first entry */
-			devlist = curdev;
-		else
-			prevdev->next = curdev;
-		/*
-		 * Fill in the entry.
-		 */
-		curdev->next = NULL;
-		(void)pcap_snprintf(desc,MAX_DESC_LENGTH,"snf%d",allports);
-		curdev->name = strdup(desc);
-		if (curdev->name == NULL) {
-			(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
-			    "snf_findalldevs strdup: %s", pcap_strerror(errno));
-			free(curdev);
-			return (-1);
-		}
+		(void)pcap_snprintf(name,MAX_DESC_LENGTH,"snf%d",allports);
 		(void)pcap_snprintf(desc,MAX_DESC_LENGTH,"Myricom Merge Bitmask All Ports snf%d",
 			allports);
-		curdev->description = strdup(desc);
-		if (curdev->description == NULL) {
-			(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
-			    "snf_findalldevs strdup1: %s", pcap_strerror(errno));
-			free(curdev->name);
-			free(curdev);
+		if (add_dev(alldevs, name, 0, desc, errbuf) == NULL)
 			return (-1);
-		}
-		curdev->addresses = NULL;
-		curdev->flags = 0;
-
 		/*
-		 * XXX - are there any actual IP addresses for
-		 * these devices?
+		 * XXX - should we give it a list of addresses with all
+		 * the addresses for all the ports?
 		 */
 	}
-	if (*devlistp == NULL)
-		/*
-		 * The passed in list was empty
-		 */
-		*devlistp = devlist;
-	else {
-		/*
-		 * Find last member of list and append our devlist to it.
-		 */
-		nextdev = *devlistp;
-		while (nextdev->next != NULL)
-			nextdev = nextdev->next;
-		nextdev->next = devlist;
-	}
 
 	return 0;
 }
@@ -545,7 +485,7 @@ snf_create(const char *device, char *ebuf, int *is_ours)
 			/* Nope, not a supported name */
 			*is_ours = 0;
 			return NULL;
-		    }
+		}
 	}
 
 	/* OK, it's probably ours. */
@@ -582,7 +522,7 @@ snf_create(const char *device, char *ebuf, int *is_ours)
  */
 
 /*
- * There are no regular interfaces, just DAG interfaces.
+ * There are no regular interfaces, just SNF interfaces.
  */
 int
 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)