Changeset 6ba84d9 for lib

Timestamp:

12/06/12 11:10:16 (8 years ago)

Author:

Shane Alcock <salcock@…>

Branches:

4.0.1-hotfixes, cachetimestamps, develop, dpdk-ndag, etsilive, getfragoff, help, libtrace4, master, ndag_format, pfring, rc-4.0.1, rc-4.0.2, rc-4.0.3, rc-4.0.4, ringdecrementfix, ringperformance, ringtimestampfixes

Children:

90e8d92

Parents:

a464de7

Message:

• Committed most of Perry's suggestions following a code review of the new ring: format

File:

• lib/format_linux.c (modified) (19 diffs)

lib/format_linux.c

@@ -77 +77 @@
  */
 #define MAX_ORDER 10
-static unsigned int max_order = MAX_ORDER;
 
 /* Cached page size, the page size shoudn't be changing */
@@ -142 +141 @@
  * support the format directly.
  */
+
+
 #define PACKET_RX_RING  5
 #define PACKET_VERSION  10
@@ -152 +153 @@
 #define TPACKET_ALIGNMENT       16
 #define TPACKET_ALIGN(x)        (((x)+TPACKET_ALIGNMENT-1)&~(TPACKET_ALIGNMENT-1))
-#define TPACKET2_HDRLEN         (TPACKET_ALIGN(sizeof(struct tpacket2_hdr)) + sizeof(struct sockaddr_ll))
+#define TPACKET_HDRLEN         (TPACKET_ALIGN(sizeof(struct tpacket2_hdr)) + sizeof(struct sockaddr_ll))
 
 enum tpacket_versions {
@@ -205 +206 @@
         /* The current frame number within the rx ring */       
         int rxring_offset;
-        /* The format this trace is using linuxring or linuxnative */
+        /* The actual format being used - ring vs int */
         libtrace_rt_types_t format;
         /* The current ring buffer layout */
         struct tpacket_req req;
+        /* Used to determine buffer size for the ring buffer */ 
+        uint32_t max_order;
 };
 
@@ -254 +257 @@
         /* The format this trace is using linuxring or linuxnative */
         libtrace_rt_types_t format;
+        /* Used to determine buffer size for the ring buffer */ 
+        uint32_t max_order;
 };
 
@@ -259 +264 @@
 #define GET_SOCKADDR_HDR(x)  ((struct sockaddr_ll *) (((char *) (x))\
         + TPACKET_ALIGN(sizeof(struct tpacket2_hdr))))
-
-#define TPACKET_HDRLEN TPACKET2_HDRLEN
 
 #define FORMAT(x) ((struct linux_format_data_t*)(x))
@@ -273 +276 @@
 
 #ifdef HAVE_NETPACKET_PACKET_H
-
 /*
  * Try figure out the best sizes for the ring buffer. Ensure that:
@@ -286 +288 @@
  * - Calculates based on max_order and buf_min
  */
-static void calculate_buffers(struct tpacket_req * req, int fd, char * uri){
+static void calculate_buffers(struct tpacket_req * req, int fd, char * uri,
+                uint32_t max_order){
         
         struct ifreq ifr;
-        unsigned mtu = LIBTRACE_PACKET_BUFSIZE;
+        unsigned max_frame = LIBTRACE_PACKET_BUFSIZE;
         pagesize = getpagesize();
 
+        strcpy(ifr.ifr_name, uri);
         /* Don't bother trying to set frame size above mtu linux will drop
-         * these anyway
+         * these anyway.
+         *
+         * Remember, that our frame also has to include a TPACKET header!
          */
-        strcpy(ifr.ifr_name, uri);
         if (ioctl(fd, SIOCGIFMTU, (caddr_t) &ifr) >= 0) 
-                mtu = ifr.ifr_mtu;
-        if(mtu > LIBTRACE_PACKET_BUFSIZE)
-                mtu = LIBTRACE_PACKET_BUFSIZE;
+                max_frame = ifr.ifr_mtu + sizeof(struct tpacket2_hdr);
+        if (max_frame > LIBTRACE_PACKET_BUFSIZE)
+                max_frame = LIBTRACE_PACKET_BUFSIZE;
 
         /* Calculate frame size */
         req->tp_frame_size = pagesize;
-        while(req->tp_frame_size < mtu && req->tp_frame_size < LIBTRACE_PACKET_BUFSIZE){
+        while(req->tp_frame_size < max_frame && 
+                        req->tp_frame_size < LIBTRACE_PACKET_BUFSIZE){
                 req->tp_frame_size <<= 1;
         }
@@ -326 +332 @@
                         (req->tp_block_size / req->tp_frame_size);
 
-        /*printf("MaxO 0x%x BS 0x%x BN 0x%x FS 0x%x FN 0x%x\n", 
+        /*
+        printf("MaxO 0x%x BS 0x%x BN 0x%x FS 0x%x FN 0x%x\n", 
                 max_order, 
                 req->tp_block_size, 
                 req->tp_block_nr, 
                 req->tp_frame_size, 
-                req->tp_frame_nr);*/
+                req->tp_frame_nr);
+        */
         
         /* In case we have some silly values*/
@@ -519 +527 @@
                                         int fd, 
                                         struct tpacket_req * req,
-                                        char ** ring_location){
+                                        char ** ring_location,
+                                        uint32_t *max_order){
         socklen_t len;
         int val;
@@ -547 +556 @@
          */
         while(1) {      
-                if (max_order <= 0) {
+                if (*max_order <= 0) {
                         return -1;
                 }
-                calculate_buffers(req, fd, uridata);
+                calculate_buffers(req, fd, uridata, *max_order);
                 if (setsockopt(fd, 
                                 SOL_PACKET, 
@@ -557 +566 @@
                                 sizeof(struct tpacket_req)) == -1) {
                         if(errno == ENOMEM){
-                                max_order--;
+                                (*max_order)--;
                         } else {
                                 return -1;
@@ -584 +593 @@
 
         /* Make it a packetmmap */
-        if(socket_to_packetmmap(libtrace->uridata, PACKET_RX_RING, FORMAT(libtrace->format_data)->fd,
-                 &FORMAT(libtrace->format_data)->req, &FORMAT(libtrace->format_data)->rx_ring) != 0){
+        if(socket_to_packetmmap(libtrace->uridata, PACKET_RX_RING, 
+                        FORMAT(libtrace->format_data)->fd,
+                        &FORMAT(libtrace->format_data)->req, 
+                        &FORMAT(libtrace->format_data)->rx_ring,
+                        &FORMAT(libtrace->format_data)->max_order) != 0){
                 trace_set_err(libtrace, TRACE_ERR_INIT_FAILED, 
                         "TPACKET2 not supported or ring buffer is too large");
@@ -592 +604 @@
                 return -1;
         }
-                
+
         return 0;
 }
@@ -614 +626 @@
 
         /* Make it a packetmmap */
-        if(socket_to_packetmmap(libtrace->uridata, PACKET_TX_RING, DATAOUT(libtrace)->fd,
-                 &DATAOUT(libtrace)->req, &DATAOUT(libtrace)->tx_ring) != 0){
+        if(socket_to_packetmmap(libtrace->uridata, PACKET_TX_RING, 
+                        DATAOUT(libtrace)->fd,
+                        &DATAOUT(libtrace)->req, 
+                        &DATAOUT(libtrace)->tx_ring,
+                        &DATAOUT(libtrace)->max_order) != 0){
                 trace_set_err_out(libtrace, TRACE_ERR_INIT_FAILED, 
                         "TPACKET2 not supported or ring buffer is too large");
@@ -834 +849 @@
                                         TO_TP_HDR(packet->header)->tp_mac, 
                                         TO_TP_HDR(packet->header)->tp_net, 
-                                        TPACKET2_HDRLEN);
+                                        TPACKET_HDRLEN);
         packet->type = rt_type;
 
@@ -1024 +1039 @@
                 if (ret < 0) {
                         if (errno != EINTR)
-                        trace_set_err(libtrace,errno,"poll()");
+                                trace_set_err(libtrace,errno,"poll()");
                         return -1;
                 }
@@ -1333 +1348 @@
 {       
         /* 
-         * Need to make frame_length + capture_length = compelete capture length 
+         * Need to make frame_length + capture_length = complete capture length 
          * so include alligment whitespace. So reverse calculate from packet.
          */
@@ -1656 +1671 @@
 
 void linuxnative_constructor(void) {
+        /* TODO: once we're happy with ring:, it would be a good idea to 
+         * swap the order of these calls so that ring: is preferred over
+         * int: if the user just gives an interface name as an input without
+         * explicitly choosing a format.
+         */
         register_format(&linuxnative);
         register_format(&linuxring);