Enhance pid file support to detect running processes

problem: cannot build on openbsd

.gitignore

@@ -1,2 +1,5 @@
 /dpinger
+/dpinger.debug
+/dpinger.full
 /dpinger.o
+/.*.swp

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2015, Denny Page
+Copyright (c) 2015-2017, Denny Page
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without

Makefile

@@ -1,9 +1,9 @@
-PROG=	dpinger
-MAN=
+#CC=gcc
+#WARNINGS=-Wall -Wextra -Wformat=2 -Wno-unused-result
 
-BINDIR=	${PREFIX}/bin
-WARNS=	6
+CC=clang
+WARNINGS=-Weverything -Wno-padded -Wno-disabled-macro-expansion -Wno-reserved-id-macro
 
-LDADD=	-lpthread
+CFLAGS=${WARNINGS} -pthread -g -O2
 
-.include <bsd.prog.mk>
+all: dpinger

Makefile.freebsd

@@ -0,0 +1,9 @@
+PROG=	dpinger
+MAN=
+
+BINDIR=	${PREFIX}/bin
+WARNS=	6
+
+LDADD=	-lpthread
+
+.include <bsd.prog.mk>

NOTES.md

@@ -0,0 +1,13 @@
+<b>Loss accuracy</b>
+
+In general, dpinger works a bit differently than other latency monitors. Rather than a "probe" that fires off and processes a handful of echo request/replies all at once, dpinger maintains a rolling array of echo requests spaced on the send interval. In other words, instead of waking up every second and sending 4 echo requests at once, dpinger sends an echo request every 250 milliseconds. When dpinger receives an echo reply, the time difference between the request packet and reply packet (latency) is recorded. There is nothing that times out an echo request/reply and records it as permanently lost.
+
+When the alert check is made, or a report is generated, dpinger goes through the array and examines each echo request. If a reply has been received, it is used as part of the overall latency calculation. If a reply has not yet been received, the amount of time since the request is compared against the loss interval. If it is greater than the loss interval, the request/reply is counted as lost in the current report. However the concept of the request/reply being lost is not a permanent decision. In subsequent reports, if a the missing reply has been received, its latency will be used instead of being counted as lost.
+
+It's important to keep in mind that latency and loss are reported as averages across the entire request set. The default time period for dpinger is 30 seconds, with an echo request being sent every 250 milliseconds. This means that the latency and loss will be reported as averages across 115-120 samples. The alert check runs every second by default. So each time, the 4 oldest entries in the set have been replaced by the 4 newest ones.
+
+Note that if you want accurate loss reporting, it is important that the number of samples be sufficient. In order to achieve 1% loss resolution, you have need more than 100 samples in the set. The calculation for loss resolution is:
+
+  100 * send_interval / (time_period - loss_interval)
+
+The default settings for dpinger report loss with an accuracy of 0.87%.

dpinger.c

@@ -1,6 +1,6 @@
 
 //
-// Copyright (c) 2015, Denny Page
+// Copyright (c) 2015-2017, Denny Page
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
@@ -27,6 +27,11 @@
 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //
 
+
+// Silly that this is required for accept4 on Linux
+#define _GNU_SOURCE
+
+
 #include <stdio.h>
 #include <errno.h>
 #include <string.h>
@@ -39,10 +44,11 @@
 #include <signal.h>
 
 #include <netdb.h>
-#include <net/if.h>
 #include <sys/socket.h>
+#include <net/if.h>
 #include <sys/un.h>
 #include <sys/stat.h>
+#include <sys/file.h>
 #include <netinet/in.h>
 #include <netinet/ip.h>
 #include <netinet/ip_icmp.h>
@@ -52,17 +58,6 @@
 #include <pthread.h>
 #include <syslog.h>
 
-// TODO:
-//
-// After December 31st, 2016, review use of fcntl() for setting non blocking
-// and close on exec. It would be preferable to use accept4(), SOCK_CLOEXEC
-// and SOCK_NONBLOCK. These are currently avoided to allow use on older
-// systems such as FreeBSD 9.3, Linux 2.6.26.
-// For Linux accept4() currently requires defining _GNU_SOURCE which we would
-// like to avoid.
-// For FreeBSD, these definitions were introduced with FreeBSD 10.0 and are
-// not present in 9.3 which is supported through 2016.
-
 
 // Who we are
 static const char *             progname;
@@ -74,16 +69,17 @@ static const char *             pidfile_name = NULL;
 // Flags
 static unsigned int             flag_rewind = 0;
 static unsigned int             flag_syslog = 0;
+static unsigned int             flag_priority = 0;
 
 // String representation of target
 #define ADDR_STR_MAX            (INET6_ADDRSTRLEN + IF_NAMESIZE + 1)
 static char                     dest_str[ADDR_STR_MAX];
 
 // Time period over which we are averaging results in ms
-static unsigned long            time_period_msec = 30000;
+static unsigned long            time_period_msec = 60000;
 
 // Interval between sends in ms
-static unsigned long            send_interval_msec = 250;
+static unsigned long            send_interval_msec = 500;
 
 // Interval before a sequence is initially treated as lost
 // Input from command line in ms and used in us
@@ -150,8 +146,8 @@ static int                      recv_sock;
 
 // IPv4 / IPv6 parameters
 static uint16_t                 af_family = AF_INET;                    // IPv6: AF_INET6
-static uint16_t                 echo_request_type = ICMP_ECHO;          // IPv6: ICMP6_ECHO_REQUEST
-static uint16_t                 echo_reply_type = ICMP_ECHOREPLY;       // IPv6: ICMP6_ECHO_REPLY
+static uint8_t                  echo_request_type = ICMP_ECHO;          // IPv6: ICMP6_ECHO_REQUEST
+static uint8_t                  echo_reply_type = ICMP_ECHOREPLY;       // IPv6: ICMP6_ECHO_REPLY
 static int                      ip_proto = IPPROTO_ICMP;                // IPv6: IPPROTO_ICMPV6
 
 // Destination address
@@ -175,18 +171,29 @@ typedef struct
     uint16_t                    sequence;
 } icmphdr_t;
 
-// Echo request header for sendto
-static icmphdr_t                echo_request;
+// Echo request/reply packet buffers
+#define IPV4_ICMP_DATA_MAX      (IP_MAXPACKET - sizeof(struct ip) - sizeof(icmphdr_t))
+#define IPV6_ICMP_DATA_MAX      (IP_MAXPACKET - sizeof(icmphdr_t))
+#define PACKET_BUFLEN           (IP_MAXPACKET + 256)
+
+static unsigned long            echo_data_len = 0;
+static unsigned int             echo_request_len = sizeof(icmphdr_t);
+static unsigned int             echo_reply_len = IP_MAXPACKET;
+static icmphdr_t *              echo_request;
+static void *                   echo_reply;
 
 // Echo id and Sequence information
 static uint16_t                 echo_id;
 static uint16_t                 next_sequence = 0;
 static uint16_t                 sequence_limit;
 
+// Receive thread ready
+static unsigned int             recv_ready = 0;
 
 //
 // Termination handler
 //
+__attribute__ ((noreturn))
 static void
 term_handler(void)
 {
@@ -206,10 +213,7 @@ term_handler(void)
 //
 // Log for abnormal events
 //
-#ifdef __GNUC__
-static void logger(const char * format, ...) __attribute__ ((format (printf, 1, 2)));
-#endif
-
+__attribute__ ((format (printf, 1, 2)))
 static void
 logger(
     const char *                format,
@@ -254,7 +258,7 @@ cksum(
     sum = (sum >> 16) + (sum & 0xFFFF);
     sum += (sum >> 16);
 
-    return ~sum;
+    return (uint16_t) ~sum;
 }
 
 
@@ -280,7 +284,7 @@ llsqrt(
         }
     }
 
-    return s;
+    return (unsigned long) s;
 }
 
 
@@ -292,7 +296,7 @@ ts_elapsed_usec(
     const struct timespec *     old,
     const struct timespec *     new)
 {
-    unsigned long               r_usec;
+    long                        r_usec;
 
     // Note that we are using monotonic clock and time cannot run backwards
     if (new->tv_nsec >= old->tv_nsec)
@@ -304,24 +308,39 @@ ts_elapsed_usec(
         r_usec = (new->tv_sec - old->tv_sec - 1) * 1000000 + (1000000000 + new->tv_nsec - old->tv_nsec) / 1000;
     }
 
-    return r_usec;
+    return (unsigned long) r_usec;
 }
 
 
 //
 // Send thread
 //
+__attribute__ ((noreturn))
 static void *
 send_thread(
+    __attribute__ ((unused))
     void *                      arg)
 {
     struct timespec             sleeptime;
+    ssize_t                     len;
     int                         r;
 
     // Set up our echo request packet
-    echo_request.type = echo_request_type;
-    echo_request.code = 0;
-    echo_request.id = echo_id;
+    memset(echo_request, 0, echo_request_len);
+    echo_request->type = echo_request_type;
+    echo_request->code = 0;
+    echo_request->id = echo_id;
+
+    // Give the recv thread a moment to initialize
+    sleeptime.tv_sec = 0;
+    sleeptime.tv_nsec = 10000; // 10us
+    do {
+        r = nanosleep(&sleeptime, NULL);
+        if (r == -1)
+        {
+            logger("nanosleep error in send thread waiting for recv thread: %d\n", errno);
+        }
+    } while (recv_ready == 0);
 
     // Set up the timespec for nanosleep
     sleeptime.tv_sec = send_interval_msec / 1000;
@@ -329,57 +348,58 @@ send_thread(
 
     while (1)
     {
-        r = nanosleep(&sleeptime, NULL);
-        if (r == -1)
-        {
-            logger("nanosleep error in send thread: %d\n", errno);
-        }
-
         // Set sequence number and checksum
-        echo_request.sequence = htons(next_sequence);
-        echo_request.cksum = 0;
-        echo_request.cksum = cksum((uint16_t *) &echo_request, sizeof(icmphdr_t));
+        echo_request->sequence = htons(next_sequence);
+        echo_request->cksum = 0;
+        echo_request->cksum = cksum((uint16_t *) echo_request, sizeof(icmphdr_t));
 
         array[next_slot].status = PACKET_STATUS_EMPTY;
         sched_yield();
+
         clock_gettime(CLOCK_MONOTONIC, &array[next_slot].time_sent);
         array[next_slot].status = PACKET_STATUS_SENT;
-
-        r = sendto(send_sock, &echo_request, sizeof(icmphdr_t), 0, (struct sockaddr *) &dest_addr, dest_addr_len);
-        if (r == -1)
+        len = sendto(send_sock, echo_request, echo_request_len, 0, (struct sockaddr *) &dest_addr, dest_addr_len);
+        if (len == -1)
         {
             logger("%s%s: sendto error: %d\n", identifier, dest_str, errno);
         }
 
         next_slot = (next_slot + 1) % array_size;
         next_sequence = (next_sequence + 1) % sequence_limit;
-    }
 
-    // notreached
-    return arg;
+        r = nanosleep(&sleeptime, NULL);
+        if (r == -1)
+        {
+            logger("nanosleep error in send thread: %d\n", errno);
+        }
+    }
 }
 
 
 //
 // Receive thread
 //
+__attribute__ ((noreturn))
 static void *
 recv_thread(
+    __attribute__ ((unused))
     void *                      arg)
 {
-    char                        packet[1024];
-    unsigned int                packet_len;
     struct sockaddr_storage     src_addr;
     socklen_t                   src_addr_len;
+    ssize_t                     len;
     icmphdr_t *                 icmp;
     struct timespec             now;
     unsigned int                array_slot;
 
+    // Thread startup complete
+    recv_ready = 1;
+
     while (1)
     {
         src_addr_len = sizeof(src_addr);
-        packet_len = recvfrom(recv_sock, &packet, sizeof(packet), 0, (struct sockaddr *) &src_addr, &src_addr_len);
-        if (packet_len == (unsigned int) -1)
+        len = recvfrom(recv_sock, echo_reply, echo_reply_len, 0, (struct sockaddr *) &src_addr, &src_addr_len);
+        if (len == -1)
         {
             logger("%s%s: recvfrom error: %d\n", identifier, dest_str, errno);
             continue;
@@ -392,25 +412,25 @@ recv_thread(
             size_t              ip_len;
 
             // With IPv4, we get the entire IP packet
-            if (packet_len < sizeof(struct ip))
+            if (len < (ssize_t) sizeof(struct ip))
             {
                 logger("%s%s: received packet too small for IP header\n", identifier, dest_str);
                 continue;
             }
-            ip = (void *) packet;
-            ip_len = ip->ip_hl << 2;
+            ip = echo_reply;
+            ip_len = (size_t) ip->ip_hl << 2;
 
-            icmp = (void *) (packet + ip_len);
-            packet_len -= ip_len;
+            icmp = (void *) ((char *) ip + ip_len);
+            len -= ip_len;
         }
         else
         {
             // With IPv6, we just get the ICMP payload
-            icmp = (void *) (packet);
+            icmp = echo_reply;
         }
 
         // This should never happen
-        if (packet_len < sizeof(icmphdr_t))
+        if (len < (ssize_t) sizeof(icmphdr_t))
         {
             logger("%s%s: received packet too small for ICMP header\n", identifier, dest_str);
             continue;
@@ -432,9 +452,6 @@ recv_thread(
         array[array_slot].latency_usec = ts_elapsed_usec(&array[array_slot].time_sent, &now);
         array[array_slot].status = PACKET_STATUS_RECEIVED;
     }
-
-    // notreached
-    return arg;
 }
 
 
@@ -450,6 +467,7 @@ report(
     struct timespec             now;
     unsigned long               packets_received = 0;
     unsigned long               packets_lost = 0;
+    unsigned long               latency_usec = 0;
     unsigned long               total_latency_usec = 0;
     unsigned long long          total_latency_usec2 = 0;
     unsigned int                slot;
@@ -463,8 +481,9 @@ report(
         if (array[slot].status == PACKET_STATUS_RECEIVED)
         {
             packets_received++;
-            total_latency_usec += array[slot].latency_usec;
-            total_latency_usec2 += array[slot].latency_usec * array[slot].latency_usec;
+            latency_usec = array[slot].latency_usec;
+            total_latency_usec += latency_usec;
+            total_latency_usec2 += (unsigned long long) latency_usec * latency_usec;
         }
         else if (array[slot].status == PACKET_STATUS_SENT &&
                  ts_elapsed_usec(&array[slot].time_sent, &now) > loss_interval_usec)
@@ -477,10 +496,12 @@ report(
 
     if (packets_received)
     {
-        *average_latency_usec = total_latency_usec / packets_received;
+        unsigned long           avg = total_latency_usec / packets_received;
+        unsigned long long      avg2 = total_latency_usec2 / packets_received;
 
-        // sqrt( (sum(rtt^2) / packets) - (sum(rtt) / packets)^2)
-        *latency_deviation = llsqrt((total_latency_usec2 / packets_received) - (total_latency_usec / packets_received) * (total_latency_usec / packets_received));
+        // stddev = sqrt((sum(rtt^2) / packets) - (sum(rtt) / packets)^2)
+        *average_latency_usec = avg;
+        *latency_deviation = llsqrt(avg2 - ((unsigned long long) avg * avg));
     }
     else
     {
@@ -502,8 +523,10 @@ report(
 //
 // Report thread
 //
+__attribute__ ((noreturn))
 static void *
 report_thread(
+    __attribute__ ((unused))
     void *                      arg)
 {
     char                        buf[OUTPUT_MAX];
@@ -511,7 +534,8 @@ report_thread(
     unsigned long               average_latency_usec;
     unsigned long               latency_deviation;
     unsigned long               average_loss_percent;
-    int                         len;
+    ssize_t                     len;
+    ssize_t                     rs;
     int                         r;
 
     // Set up the timespec for nanosleep
@@ -534,33 +558,32 @@ report_thread(
             logger("error formatting output in report thread\n");
         }
 
-        r = write(report_fd, buf, len);
-        if (r == -1)
+        rs = write(report_fd, buf, (size_t) len);
+        if (rs == -1)
         {
             logger("write error in report thread: %d\n", errno);
         }
-        else if (r != len)
+        else if (rs != len)
         {
-            logger("short write in report thread: %d/%d\n", r, len);
+            logger("short write in report thread: %zd/%zd\n", rs, len);
         }
 
         if (flag_rewind)
         {
-            ftruncate(report_fd, len);
-            lseek(report_fd, SEEK_SET, 0);
+            (void) ftruncate(report_fd, len);
+            (void) lseek(report_fd, SEEK_SET, 0);
         }
     }
-
-    // notreached
-    return arg;
 }
 
 
 //
 // Alert thread
 //
+__attribute__ ((noreturn))
 static void *
 alert_thread(
+    __attribute__ ((unused))
     void *                      arg)
 {
     struct timespec             sleeptime;
@@ -654,16 +677,15 @@ alert_thread(
             }
         }
     }
-
-    // notreached
-    return arg;
 }
 
 //
 // Unix socket thread
 //
+__attribute__ ((noreturn))
 static void *
 usocket_thread(
+    __attribute__ ((unused))
     void *                      arg)
 {
     char                        buf[OUTPUT_MAX];
@@ -671,14 +693,20 @@ usocket_thread(
     unsigned long               latency_deviation;
     unsigned long               average_loss_percent;
     int                         sock_fd;
-    int                         len;
+    ssize_t                     len;
+    ssize_t                     rs;
     int                         r;
 
     while (1)
     {
+#if defined(DISABLE_ACCEPT4)
+        // Legacy
         sock_fd = accept(usocket_fd, NULL, NULL);
         (void) fcntl(sock_fd, F_SETFL, FD_CLOEXEC);
         (void) fcntl(sock_fd, F_SETFL, fcntl(sock_fd, F_GETFL, 0) | O_NONBLOCK);
+#else
+        sock_fd = accept4(usocket_fd, NULL, NULL, SOCK_NONBLOCK | SOCK_CLOEXEC);
+#endif
 
         report(&average_latency_usec, &latency_deviation, &average_loss_percent);
 
@@ -688,14 +716,14 @@ usocket_thread(
             logger("error formatting output in usocket thread\n");
         }
 
-        r = write(sock_fd, buf, len);
-        if (r == -1)
+        rs = write(sock_fd, buf, (size_t) len);
+        if (rs == -1)
         {
             logger("write error in usocket thread: %d\n", errno);
         }
-        else if (r != len)
+        else if (rs != len)
         {
-            logger("short write in usocket thread: %d/%d\n", r, len);
+            logger("short write in usocket thread: %zd/%zd\n", rs, len);
         }
 
         r = close(sock_fd);
@@ -704,9 +732,6 @@ usocket_thread(
             logger("close error in usocket thread: %d\n", errno);
         }
     }
-
-    // notreached
-    return arg;
 }
 
 
@@ -719,10 +744,10 @@ get_time_arg_msec(
     const char *                arg,
     unsigned long *             value)
 {
-    unsigned long               t;
+    long                        t;
     char *                      suffix;
 
-    t = strtoul(arg, &suffix, 10);
+    t = strtol(arg, &suffix, 10);
     if (*suffix == 'm')
     {
         // Milliseconds
@@ -731,17 +756,17 @@ get_time_arg_msec(
     else if (*suffix == 's')
     {
         // Seconds
-        *value *= 1000;
+        t *= 1000;
         suffix++;
     }
 
-    // Garbage in the number?
-    if (*suffix != 0)
+    // Invalid specification?
+    if (t < 0 || *suffix != 0)
     {
         return 1;
     }
 
-    *value = t;
+    *value = (unsigned long) t;
     return 0;
 }
 
@@ -754,22 +779,57 @@ get_percent_arg(
     const char *                arg,
     unsigned long *             value)
 {
-    unsigned long               t;
+    long                        t;
     char *                      suffix;
 
-    t = strtoul(arg, &suffix, 10);
+    t = strtol(arg, &suffix, 10);
     if (*suffix == '%')
     {
         suffix++;
     }
 
-    // Garbage in the number?
-    if (*suffix != 0 || t > 100)
+    // Invalid specification?
+    if (t < 0 || t > 100 || *suffix != 0)
     {
         return 1;
     }
 
-    *value = t;
+    *value = (unsigned long) t;
+    return 0;
+}
+
+
+//
+// Decode a byte length argument
+//
+static int
+get_length_arg(
+    const char *                arg,
+    unsigned long *             value)
+{
+    long                        t;
+    char *                      suffix;
+
+    t = strtol(arg, &suffix, 10);
+    if (*suffix == 'b')
+    {
+        // Bytes
+        suffix++;
+    }
+    else if (*suffix == 'k')
+    {
+        // Kilobytes
+        t *= 1024;
+        suffix++;
+    }
+
+    // Invalid specification?
+    if (t < 0 || *suffix != 0)
+    {
+        return 1;
+    }
+
+    *value = (unsigned long) t;
     return 0;
 }
 
@@ -781,16 +841,18 @@ static void
 usage(void)
 {
     fprintf(stderr, "Usage:\n");
-    fprintf(stderr, "  %s [-f] [-R] [-S] [-B bind_addr] [-s send_interval] [-l loss_interval] [-t time_period] [-r report_interval] [-o output_file] [-A alert_interval] [-D latency_alarm] [-L loss_alarm] [-C alert_cmd] [-i identifier] [-u usocket] [-p pidfile] dest_addr\n\n", progname);
+    fprintf(stderr, "  %s [-f] [-R] [-S] [-P] [-B bind_addr] [-s send_interval] [-l loss_interval] [-t time_period] [-r report_interval] [-d data_length] [-o output_file] [-A alert_interval] [-D latency_alarm] [-L loss_alarm] [-C alert_cmd] [-i identifier] [-u usocket] [-p pidfile] dest_addr\n\n", progname);
     fprintf(stderr, "  options:\n");
     fprintf(stderr, "    -f run in foreground\n");
     fprintf(stderr, "    -R rewind output file between reports\n");
     fprintf(stderr, "    -S log warnings via syslog\n");
+    fprintf(stderr, "    -P priority scheduling for receive thread (requires root)\n");
     fprintf(stderr, "    -B bind (source) address\n");
-    fprintf(stderr, "    -s time interval between echo requests (default 250ms)\n");
-    fprintf(stderr, "    -l time interval before packets are treated as lost (default 5x send interval)\n");
-    fprintf(stderr, "    -t time period over which results are averaged (default 30s)\n");
+    fprintf(stderr, "    -s time interval between echo requests (default 500ms)\n");
+    fprintf(stderr, "    -l time interval before packets are treated as lost (default 4x send interval)\n");
+    fprintf(stderr, "    -t time period over which results are averaged (default 60s)\n");
     fprintf(stderr, "    -r time interval between reports (default 1s)\n");
+    fprintf(stderr, "    -d data length (default 0)\n");
     fprintf(stderr, "    -o output file for reports (default stdout)\n");
     fprintf(stderr, "    -A time interval between alerts (default 1s)\n");
     fprintf(stderr, "    -D time threshold for latency alarm (default none)\n");
@@ -816,19 +878,17 @@ usage(void)
 //
 // Fatal error
 //
+__attribute__ ((noreturn, format (printf, 1, 2)))
 static void
 fatal(
     const char *                format,
     ...)
 {
-    if (format)
-    {
-        va_list                 args;
+    va_list                 args;
 
-        va_start(args, format);
-        vfprintf(stderr, format, args);
-        va_end(args);
-    }
+    va_start(args, format);
+    vfprintf(stderr, format, args);
+    va_end(args);
 
     exit(EXIT_FAILURE);
 }
@@ -852,7 +912,7 @@ parse_args(
 
     progname = argv[0];
 
-    while((opt = getopt(argc, argv, "fRSB:s:l:t:r:o:A:D:L:C:i:u:p:")) != -1)
+    while((opt = getopt(argc, argv, "fRSPB:s:l:t:r:d:o:A:D:L:C:i:u:p:")) != -1)
     {
         switch (opt)
         {
@@ -868,6 +928,10 @@ parse_args(
             flag_syslog = 1;
             break;
 
+        case 'P':
+            flag_priority = 1;
+            break;
+
         case 'B':
             bind_arg = optarg;
             break;
@@ -904,6 +968,14 @@ parse_args(
             }
             break;
 
+        case 'd':
+            r = get_length_arg(optarg, &echo_data_len);
+            if (r)
+            {
+                fatal("invalid data length %s\n", optarg);
+            }
+            break;
+
         case 'o':
             report_name = optarg;
             break;
@@ -918,7 +990,7 @@ parse_args(
 
         case 'D':
             r = get_time_arg_msec(optarg, &latency_alarm_threshold_msec);
-            if (r || latency_alarm_threshold_msec == 0)
+            if (r)
             {
                 fatal("invalid latency alarm threshold %s\n", optarg);
             }
@@ -927,7 +999,7 @@ parse_args(
 
         case 'L':
             r = get_percent_arg(optarg, &loss_alarm_threshold_percent);
-            if (r || loss_alarm_threshold_percent == 0)
+            if (r)
             {
                 fatal("invalid loss alarm threshold %s\n", optarg);
             }
@@ -935,7 +1007,7 @@ parse_args(
 
         case 'C':
             alert_cmd_offset = strlen(optarg);
-            alert_cmd = malloc (alert_cmd_offset + OUTPUT_MAX);
+            alert_cmd = malloc(alert_cmd_offset + OUTPUT_MAX);
             if (alert_cmd == NULL)
             {
                 fatal("malloc of alert command buffer failed\n");
@@ -947,7 +1019,7 @@ parse_args(
             len = strlen(optarg);
             if (len >= sizeof(identifier) - 1)
             {
-                fatal("identifier argument too large (max %u bytes)\n", sizeof(identifier) - 1);
+                fatal("identifier argument too large (max %u bytes)\n", (unsigned) sizeof(identifier) - 1);
             }
             // optarg with a space appended
             memcpy(identifier, optarg, len);
@@ -965,7 +1037,7 @@ parse_args(
 
         default:
             usage();
-            fatal(NULL);
+            exit(EXIT_FAILURE);
         }
     }
 
@@ -973,7 +1045,7 @@ parse_args(
     if (argc != optind + 1)
     {
         usage();
-        fatal(NULL);
+        exit(EXIT_FAILURE);
     }
     dest_arg = argv[optind];
 
@@ -983,17 +1055,17 @@ parse_args(
         fatal("no activity enabled\n");
     }
 
-    // Ensure we have something to average over
-    if (time_period_msec < send_interval_msec)
+    // Ensure there is a minimum of one resolved slot at all times
+    if (time_period_msec <= send_interval_msec * 2 + loss_interval_msec)
     {
-        fatal("time period cannot be less than send interval\n");
+        fatal("the time period must be greater than twice the send interval plus the loss interval\n");
     }
 
     // Ensure we don't have sequence space issues. This really should only be hit by
     // complete accident. Even a ratio of 16384:1 would be excessive.
     if (time_period_msec / send_interval_msec > 65536)
     {
-        fatal("ratio of time period to send interval cannot exceed 65536:1\n");
+        fatal("the ratio of time period to send interval cannot exceed 65536:1\n");
     }
 
     // Check destination address
@@ -1041,6 +1113,27 @@ parse_args(
         memcpy(&bind_addr, addr_info->ai_addr, bind_addr_len);
         freeaddrinfo(addr_info);
     }
+
+    // Check requested data length
+    if (echo_data_len)
+    {
+        if (af_family == AF_INET)
+        {
+            if (echo_data_len > IPV4_ICMP_DATA_MAX)
+            {
+                fatal("data length too large for IPv4 - maximum is %u bytes\n", (unsigned) IPV4_ICMP_DATA_MAX);
+            }
+        }
+        else
+        {
+            if (echo_data_len > IPV6_ICMP_DATA_MAX)
+            {
+                fatal("data length too large for IPv6 - maximum is %u bytes\n", (unsigned) IPV6_ICMP_DATA_MAX);
+            }
+        }
+
+        echo_request_len += echo_data_len;
+    }
 }
 
 
@@ -1053,9 +1146,14 @@ main(
     char                        *argv[])
 {
     char                        bind_str[ADDR_STR_MAX] = "(none)";
+    char                        pidbuf[64];
     int                         pidfile_fd = -1;
+    pid_t                       pid;
     pthread_t                   thread;
     struct                      sigaction act;
+    int                         buflen = PACKET_BUFLEN;
+    ssize_t                     len;
+    ssize_t                     rs;
     int                         r;
 
     // Handle command line args
@@ -1069,6 +1167,7 @@ main(
         fatal("cannot create send socket\n");
     }
     (void) fcntl(send_sock, F_SETFL, FD_CLOEXEC);
+    (void) setsockopt(send_sock, SOL_SOCKET, SO_SNDBUF, &buflen, sizeof(buflen));
 
     recv_sock = socket(af_family, SOCK_RAW, ip_proto);
     if (recv_sock == -1)
@@ -1077,6 +1176,7 @@ main(
         fatal("cannot create recv socket\n");
     }
     (void) fcntl(recv_sock, F_SETFL, FD_CLOEXEC);
+    (void) setsockopt(recv_sock, SOL_SOCKET, SO_RCVBUF, &buflen, sizeof(buflen));
 
     // Bind our sockets to an address if requested
     if (bind_addr_len)
@@ -1096,8 +1196,68 @@ main(
     }
 
     // Drop privileges
-    r = setgid(getgid());
-    r = setuid(getuid());
+    (void) setgid(getgid());
+    (void) setuid(getuid());
+
+    // Create pid file
+    if (pidfile_name)
+    {
+        pidfile_fd = open(pidfile_name, O_WRONLY | O_CREAT | O_EXCL | O_CLOEXEC, 0644);
+        if (pidfile_fd != -1)
+        {
+            // Lock the pid file
+            r = flock(pidfile_fd, LOCK_EX | LOCK_NB);
+            if (r == -1)
+            {
+                perror("flock");
+                fatal("error locking pid file\n");
+            }
+        }
+        else
+        {
+            // Pid file already exists?
+            pidfile_fd = open(pidfile_name, O_RDWR | O_CREAT | O_CLOEXEC, 0644);
+            if (pidfile_fd == -1)
+            {
+                perror("open");
+                fatal("cannot create/open pid file %s\n", pidfile_name);
+            }
+
+            // Lock the pid file
+            r = flock(pidfile_fd, LOCK_EX | LOCK_NB);
+            if (r == -1)
+            {
+                fatal("pid file %s is in use by another process\n", pidfile_name);
+            }
+
+            // Check for existing pid
+            rs = read(pidfile_fd, pidbuf, sizeof(pidbuf) - 1);
+            if (rs > 0)
+            {
+                pidbuf[rs] = 0;
+
+                pid = (pid_t) strtol(pidbuf, NULL, 10);
+                if (pid > 0)
+                {
+                    // Is the pid still alive?
+                    r = kill(pid, 0);
+                    if (r == 0)
+                    {
+                        fatal("pid file %s is in use by process %u\n", pidfile_name, (unsigned int) pid);
+                    }
+                }
+            }
+
+            // Reset the pid file
+            (void) lseek(pidfile_fd, 0, 0);
+            r = ftruncate(pidfile_fd, 0);
+            if (r == -1)
+            {
+                perror("ftruncate");
+                fatal("cannot write pid file %s\n", pidfile_name);
+            }
+        }
+    }
 
     // Create report file
     if (report_name)
@@ -1131,7 +1291,6 @@ main(
             fatal("cannot create unix domain socket\n");
         }
         (void) fcntl(usocket_fd, F_SETFL, FD_CLOEXEC);
-
         (void) unlink(usocket_name);
 
         memset(&uaddr, 0, sizeof(uaddr));
@@ -1159,31 +1318,20 @@ main(
         }
     }
 
-    // Create pid file
-    if (pidfile_name)
-    {
-        pidfile_fd = open(pidfile_name, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, 0644);
-        if (pidfile_fd == -1)
-        {
-            perror("open");
-            fatal("cannot open/create pid file %s\n", pidfile_name);
-        }
-    }
-
     // End of general errors from command line options
 
     // Self background
     if (foreground == 0)
     {
-        r = fork();
+        pid = fork();
 
-        if (r == -1)
+        if (pid == -1)
         {
             perror("fork");
             fatal("cannot background\n");
         }
 
-        if (r)
+        if (pid)
         {
             _exit(EXIT_SUCCESS);
         }
@@ -1194,23 +1342,20 @@ main(
     // Termination handler
     memset(&act, 0, sizeof(act));
     act.sa_handler = (void (*)(int)) term_handler;
-    sigaction(SIGTERM, &act, NULL);
-    sigaction(SIGINT, &act, NULL);
+    (void) sigaction(SIGTERM, &act, NULL);
+    (void) sigaction(SIGINT, &act, NULL);
 
     // Write pid file
     if (pidfile_fd != -1)
     {
-        char                    buf[64];
-        int                     len;
-
-        len = snprintf(buf, sizeof(buf), "%u\n", (unsigned) getpid());
-        if (len < 0 || (size_t) len > sizeof(buf))
+        len = snprintf(pidbuf, sizeof(pidbuf), "%u\n", (unsigned) getpid());
+        if (len < 0 || (size_t) len > sizeof(pidbuf))
         {
             fatal("error formatting pidfile\n");
         }
 
-        r = write(pidfile_fd, buf, len);
-        if (r == -1)
+        rs = write(pidfile_fd, pidbuf, (size_t) len);
+        if (rs == -1)
         {
             perror("write");
             fatal("error writing pidfile\n");
@@ -1225,17 +1370,25 @@ main(
     }
 
     // Create the array
-    array_size = time_period_msec / send_interval_msec;
+    array_size = (unsigned int) (time_period_msec / send_interval_msec);
     array = calloc(array_size, sizeof(*array));
     if (array == NULL)
     {
         fatal("calloc of packet array failed\n");
     }
 
+    // Allocate the echo request/reply packet buffers
+    echo_request = (icmphdr_t *) malloc(echo_request_len);
+    echo_reply = malloc(echo_reply_len);
+    if (echo_request == NULL || echo_reply == NULL)
+    {
+        fatal("malloc of packet buffers failed\n");
+    }
+
     // Set the default loss interval
     if (loss_interval_msec == 0)
     {
-        loss_interval_msec = send_interval_msec * 5;
+        loss_interval_msec = send_interval_msec * 4;
     }
     loss_interval_usec = loss_interval_msec * 1000;
 
@@ -1255,19 +1408,19 @@ main(
         }
     }
 
-    logger("send_interval %lums  loss_interval %lums  time_period %lums  report_interval %lums  alert_interval %lums  latency_alarm %lums  loss_alarm %lu%%  dest_addr %s  bind_addr %s  identifier \"%s\"\n",
-           send_interval_msec, loss_interval_msec, time_period_msec, report_interval_msec,
+    logger("send_interval %lums  loss_interval %lums  time_period %lums  report_interval %lums  data_len %lu  alert_interval %lums  latency_alarm %lums  loss_alarm %lu%%  dest_addr %s  bind_addr %s  identifier \"%s\"\n",
+           send_interval_msec, loss_interval_msec, time_period_msec, report_interval_msec, echo_data_len,
            alert_interval_msec, latency_alarm_threshold_msec, loss_alarm_threshold_percent,
            dest_str, bind_str, identifier);
 
     // Set my echo id
-    echo_id = htons(getpid());
+    echo_id = htons((uint16_t) getpid());
 
     // Set the limit for sequence number to ensure a multiple of array size
-    sequence_limit = array_size;
+    sequence_limit = (uint16_t) array_size;
     while ((sequence_limit & 0x8000) == 0)
     {
-        sequence_limit = sequence_limit << 1;
+        sequence_limit <<= 1;
     }
 
     // Create recv thread
@@ -1278,6 +1431,27 @@ main(
         fatal("cannot create recv thread\n");
     }
 
+    // Set priority on recv thread if requested
+    if (flag_priority)
+    {
+        struct sched_param          thread_sched_param;
+
+        r = sched_get_priority_min(SCHED_RR);
+        if (r == -1)
+        {
+            perror("sched_get_priority_min");
+            fatal("cannot determin minimum shceduling priority for SCHED_RR\n");
+        }
+        thread_sched_param.sched_priority = r;
+
+        r = pthread_setschedparam(thread, SCHED_RR, &thread_sched_param);
+        if (r != 0)
+        {
+            perror("pthread_setschedparam");
+            fatal("cannot set receive thread priority\n");
+        }
+    }
+
     // Create send thread
     r = pthread_create(&thread, NULL, &send_thread, NULL);
     if (r != 0)

rrd/README.md

@@ -0,0 +1,25 @@
+Example scripts for creating RRD graphs with dpinger
+
+<br>
+
+Files and Usage:
+
+    dpinger_rrd_create <name>
+
+Create the rrd initial file.
+
+    dpinger_rrd_update <name> <target> <additional dpinger options>
+
+Daemon updater script. Runs dpinger and feeds the rrd file.
+
+    dpinger_rrd_gencgi <name>
+
+Generate a cgi script that displays graphs.
+
+    dpinger_rrd_graph <name>
+
+Generate png files for use with static html
+
+    sample.html
+
+Sample static html to display graphs.

rrd/dpinger_rrd_create

@@ -0,0 +1,30 @@
+#!/bin/sh
+
+if [ $# -ne 1 ]
+then
+    echo "usage: $0 name"
+    exit 1
+fi
+name="$1"
+
+rrdfile="${name}.rrd"
+echo "Creating rrd file ${rrdfile}"
+
+
+# Time duration method doesn't work in all versions of rrdtool
+#rrdtool create "${rrdfile}" --step 1m \
+#    DS:latency:GAUGE:5m:0:U \
+#    DS:stddev:GAUGE:5m:0:U \
+#    DS:loss:GAUGE:5m:0:100 \
+#    RRA:AVERAGE:0.5:1m:15d \
+#    RRA:AVERAGE:0.5:5m:90d \
+#    RRA:AVERAGE:0.5:1h:3y
+
+# This method works in all versions
+rrdtool create "${rrdfile}" --step 60 \
+    DS:latency:GAUGE:300:0:U \
+    DS:stddev:GAUGE:300:0:U \
+    DS:loss:GAUGE:300:0:100 \
+    RRA:AVERAGE:0.5:1:21600 \
+    RRA:AVERAGE:0.5:5:25920 \
+    RRA:AVERAGE:0.5:60:26352

rrd/dpinger_rrd_gencgi

@@ -0,0 +1,140 @@
+#!/bin/sh
+
+if [ $# -ne 2 ]
+then
+    echo "usage: $0 rrdname pngname"
+    exit 1
+fi
+rrdname="${1}"
+pngname="${2}"
+
+# Prefixes for rrd and png files. Note that if the prefix is a directory, it must incldue the trailing slash
+# If no value is set, the files are located in the current directory when the cgi script runs
+rrdprefix=
+pngprefix=/tmp/
+
+
+# Graph dimensions
+#graph_height=240
+#graph_width=720
+graph_height=280
+graph_width=840
+
+# Preferred font
+font="DejaVuSansMono"
+
+# Latency breakpoints in milliseconds
+latency_s0=20
+latency_s1=40
+latency_s2=80
+latency_s3=160
+latency_s4=320
+
+# Latency colors
+latency_c0="dddddd"
+latency_c1="ddbbbb"
+latency_c2="d4aaaa"
+latency_c3="cc9999"
+latency_c4="c38888"
+latency_c5="bb7777"
+
+# Standard deviation color & opacity
+stddev_c="55333355"
+
+# Loss color
+loss_c="ee0000"
+
+
+gen_graph()
+{
+    png=$1
+    rrd=$2
+    start=$3
+    end=$4
+    step=$5
+    description=$6
+
+    echo "<RRD::GRAPH \"${png}\""
+        echo "--lazy"
+        echo "--start \"${start}\" --end \"${end}\" --step \"${step}\""
+        echo "--height ${graph_height} --width ${graph_width}"
+        echo "--title \"Average Latency and Packet Loss - ${description}\""
+        echo "--disable-rrdtool-tag"
+        echo "--color BACK#ffffff"
+        echo "--font DEFAULT:9:\"${font}\""
+        echo "--font AXIS:8:\"${font}\""
+
+        echo "DEF:latency_us=\"${rrd}\":latency:AVERAGE:step=\"${step}\""
+        echo "CDEF:latency=latency_us,1000,/"
+        echo "CDEF:latency_s0=latency,${latency_s0},MIN"
+        echo "CDEF:latency_s1=latency,${latency_s1},MIN"
+        echo "CDEF:latency_s2=latency,${latency_s2},MIN"
+        echo "CDEF:latency_s3=latency,${latency_s3},MIN"
+        echo "CDEF:latency_s4=latency,${latency_s4},MIN"
+        echo "VDEF:latency_min=latency,MINIMUM"
+        echo "VDEF:latency_max=latency,MAXIMUM"
+        echo "VDEF:latency_avg=latency,AVERAGE"
+        echo "VDEF:latency_last=latency,LAST"
+
+        echo "DEF:stddev_us=\"${rrd}\":stddev:AVERAGE:step=\"${step}\""
+        echo "CDEF:stddev=stddev_us,1000,/"
+        echo "VDEF:stddev_min=stddev,MINIMUM"
+        echo "VDEF:stddev_max=stddev,MAXIMUM"
+        echo "VDEF:stddev_avg=stddev,AVERAGE"
+        echo "VDEF:stddev_last=stddev,LAST"
+
+        echo "DEF:loss=\"${rrd}\":loss:AVERAGE:step=\"${step}\""
+        echo "CDEF:loss_neg=loss,-1,*"
+        echo "VDEF:loss_min=loss,MINIMUM"
+        echo "VDEF:loss_max=loss,MAXIMUM"
+        echo "VDEF:loss_avg=loss,AVERAGE"
+        echo "VDEF:loss_last=loss,LAST"
+
+        echo "COMMENT:\"                         Min              Max              Avg             Last\n\""
+
+        echo "COMMENT:\"     \""
+        echo "AREA:latency#${latency_c5}"
+        echo "AREA:latency_s4#${latency_c4}"
+        echo "AREA:latency_s3#${latency_c3}"
+        echo "AREA:latency_s2#${latency_c2}"
+        echo "AREA:latency_s1#${latency_c1}"
+        echo "AREA:latency_s0#${latency_c0}"
+        echo "LINE1:latency#000000:\"Latency  \""
+        echo "GPRINT:\"latency_min:%8.3lf ms\t\""
+        echo "GPRINT:\"latency_max:%8.3lf ms\t\""
+        echo "GPRINT:\"latency_avg:%8.3lf ms\t\""
+        echo "GPRINT:\"latency_last:%8.3lf ms\n\""
+
+        echo "COMMENT:\"     \""
+        echo "LINE1:stddev#${stddev_c}:\"Stddev   \""
+        echo "GPRINT:\"stddev_min:%8.3lf ms\t\""
+        echo "GPRINT:\"stddev_max:%8.3lf ms\t\""
+        echo "GPRINT:\"stddev_avg:%8.3lf ms\t\""
+        echo "GPRINT:\"stddev_last:%8.3lf ms\n\""
+
+        echo "COMMENT:\"     \""
+        echo "AREA:loss_neg#${loss_c}:\"Loss         \""
+        echo "GPRINT:\"loss_min:%4.1lf %%\t\t\""
+        echo "GPRINT:\"loss_max:%4.1lf %%\t\t\""
+        echo "GPRINT:\"loss_avg:%4.1lf %%\t\t\""
+        echo "GPRINT:\"loss_last:%4.1lf %%\n\""
+        echo "COMMENT:\" \n\""
+        echo "GPRINT:\"latency_last:Ending at %H\\:%M on %B %d, %Y\\r:strftime\""
+
+        echo ">"
+        echo "<p>"
+}
+
+(
+    echo "#!/usr/bin/rrdcgi"
+    echo "<html> <head> <title>Latency Statistics for ${rrdname}</title> </head> <body>"
+
+    gen_graph "${pngprefix}${pngname}-1.png" "${rrdprefix}${rrdname}.rrd" "now-8h" "now" "60" "Last 8 hours - 1 minute intervals"
+    gen_graph "${pngprefix}${pngname}-2.png" "${rrdprefix}${rrdname}.rrd" "now-36h" "now" "300" "Last 36 hours - 5 minute intervals"
+    gen_graph "${pngprefix}${pngname}-3.png" "${rrdprefix}${rrdname}.rrd" "now-8d" "now" "1800" "Last 8 days - 30 minute intervals"
+    gen_graph "${pngprefix}${pngname}-4.png" "${rrdprefix}${rrdname}.rrd" "now-60d" "now" "14400" "Last 60 days - 4 hour intervals"
+    gen_graph "${pngprefix}${pngname}-5.png" "${rrdprefix}${rrdname}.rrd" "now-1y" "now" "86400" "Last 1 year - 1 day intervals"
+    gen_graph "${pngprefix}${pngname}-6.png" "${rrdprefix}${rrdname}.rrd" "now-4y" "now" "86400" "Last 4 years - 1 day intervals"
+
+    echo "</body> </html>"
+) > "${pngname}.cgi"

rrd/dpinger_rrd_graph

@@ -0,0 +1,131 @@
+#!/bin/sh
+
+if [ $# -ne 2 ]
+then
+    echo "usage: $0 rrdname pngname"
+    exit 1
+fi
+rrdname="${1}"
+pngname="${2}"
+
+# Prefixes for rrd and png files. Note that if the prefix is a directory, it must incldue the trailing slash
+# If no value is set, the files are located in the current directory
+rrdprefix=
+pngprefix=/tmp/
+
+# Graph dimensions
+graph_height=240
+graph_width=720
+#graph_height=280
+#graph_width=840
+
+# Preferred font
+font="DejaVuSansMono"
+
+# Latency breakpoints in milliseconds
+latency_s0=20
+latency_s1=40
+latency_s2=80
+latency_s3=160
+latency_s4=320
+
+# Latency colors
+latency_c0="dddddd"
+latency_c1="ddbbbb"
+latency_c2="d4aaaa"
+latency_c3="cc9999"
+latency_c4="c38888"
+latency_c5="bb7777"
+
+# Standard deviation color & opacity
+stddev_c="55333355"
+
+# Loss color
+loss_c="ee0000"
+
+
+gen_graph()
+{
+    png=$1
+    rrd=$2
+    start=$3
+    end=$4
+    step=$5
+    description=$6
+
+    rrdtool graph "${png}" \
+        --lazy \
+        --start "${start}" --end "${end}" --step "${step}" \
+        --height "${graph_height}" --width "${graph_width}" \
+        --title "Average Latency and Packet Loss - ${description}" \
+        --disable-rrdtool-tag \
+        --color BACK#ffffff \
+        --font DEFAULT:9:"${font}" \
+        --font AXIS:8:"${font}" \
+        \
+        DEF:latency_us="${rrd}":latency:AVERAGE:step="${step}" \
+        CDEF:latency=latency_us,1000,/ \
+        CDEF:latency_s0=latency,${latency_s0},MIN \
+        CDEF:latency_s1=latency,${latency_s1},MIN \
+        CDEF:latency_s2=latency,${latency_s2},MIN \
+        CDEF:latency_s3=latency,${latency_s3},MIN \
+        CDEF:latency_s4=latency,${latency_s4},MIN \
+        VDEF:latency_min=latency,MINIMUM \
+        VDEF:latency_max=latency,MAXIMUM \
+        VDEF:latency_avg=latency,AVERAGE \
+        VDEF:latency_last=latency,LAST \
+        \
+        DEF:stddev_us="${rrd}":stddev:AVERAGE:step="${step}" \
+        CDEF:stddev=stddev_us,1000,/ \
+        VDEF:stddev_min=stddev,MINIMUM \
+        VDEF:stddev_max=stddev,MAXIMUM \
+        VDEF:stddev_avg=stddev,AVERAGE \
+        VDEF:stddev_last=stddev,LAST \
+        \
+        DEF:loss="${rrd}":loss:AVERAGE:step="${step}" \
+        CDEF:loss_neg=loss,-1,* \
+        VDEF:loss_min=loss,MINIMUM \
+        VDEF:loss_max=loss,MAXIMUM \
+        VDEF:loss_avg=loss,AVERAGE \
+        VDEF:loss_last=loss,LAST \
+        \
+        COMMENT:"                         Min              Max              Avg             Last\n" \
+        \
+        COMMENT:"     " \
+        AREA:latency#${latency_c5} \
+        AREA:latency_s4#${latency_c4} \
+        AREA:latency_s3#${latency_c3} \
+        AREA:latency_s2#${latency_c2} \
+        AREA:latency_s1#${latency_c1} \
+        AREA:latency_s0#${latency_c0} \
+        LINE1:latency#000000:"Latency  " \
+        GPRINT:"latency_min:%8.3lf ms\t" \
+        GPRINT:"latency_max:%8.3lf ms\t" \
+        GPRINT:"latency_avg:%8.3lf ms\t" \
+        GPRINT:"latency_last:%8.3lf ms\n" \
+        \
+        COMMENT:"     " \
+        LINE1:stddev#${stddev_c}:"Stddev   " \
+        GPRINT:"stddev_min:%8.3lf ms\t" \
+        GPRINT:"stddev_max:%8.3lf ms\t" \
+        GPRINT:"stddev_avg:%8.3lf ms\t" \
+        GPRINT:"stddev_last:%8.3lf ms\n" \
+        \
+        COMMENT:"     " \
+        AREA:loss_neg#${loss_c}:"Loss         " \
+        GPRINT:"loss_min:%4.1lf %%\t\t" \
+        GPRINT:"loss_max:%4.1lf %%\t\t" \
+        GPRINT:"loss_avg:%4.1lf %%\t\t" \
+        GPRINT:"loss_last:%4.1lf %%\n" \
+        \
+        COMMENT:" \n" \
+        GPRINT:"latency_last:Ending at %H\:%M on %B %d, %Y\r:strftime"
+}
+
+
+gen_graph "${pngprefix}${pngname}-1.png" "${rrdprefix}${rrdname}.rrd" "now-8h" "now" "60" "Last 8 hours - 1 minute intervals"
+gen_graph "${pngprefix}${pngname}-2.png" "${rrdprefix}${rrdname}.rrd" "now-36h" "now" "300" "Last 36 hours - 5 minute intervals"
+gen_graph "${pngprefix}${pngname}-3.png" "${rrdprefix}${rrdname}.rrd" "now-8d" "now" "1800" "Last 8 days - 30 minute intervals"
+gen_graph "${pngprefix}${pngname}-4.png" "${rrdprefix}${rrdname}.rrd" "now-60d" "now" "14400" "Last 60 days - 4 hour intervals"
+gen_graph "${pngprefix}${pngname}-5.png" "${rrdprefix}${rrdname}.rrd" "now-1y" "now" "86400" "Last 1 year - 1 day intervals"
+gen_graph "${pngprefix}${pngname}-6.png" "${rrdprefix}${rrdname}.rrd" "now-4y" "now" "86400" "Last 4 years - 1 day intervals"

rrd/dpinger_rrd_update

@@ -0,0 +1,27 @@
+#!/bin/sh
+
+if [ $# -lt 2 ]
+then
+    echo "usage: $0 rrdname targetip [dpinger options]"
+    exit 1
+fi
+name="$1"
+targetip="$2"
+shift 2
+options=$*
+
+# Where the dpinger executable is located
+dpinger=/usr/local/bin/dpinger
+
+
+rrdfile="${name}.rrd"
+if [ \! -w ${rrdfile} ]
+then
+    echo "$0: file \"${rrdfile}\" does not exist or is not writable"
+    exit 1
+fi
+
+${dpinger} -f ${options} -s 500m -t 60s -r 60s ${targetip} |
+while read -r latency stddev loss; do
+    rrdtool update "${rrdfile}" -t latency:stddev:loss "N:$latency:$stddev:$loss"
+done

rrd/sample.html

@@ -0,0 +1,16 @@
+<html>
+    <head><title>>Latency Statistics for WAN</title></head>
+    <body>
+        <img src="/tmp/wan-1.png" alt="wan-1">
+        <p>
+        <img src="/tmp/wan-2.png" alt="wan-2">
+        <p>
+        <img src="/tmp/wan-3.png" alt="wan-3">
+        <p>
+        <img src="/tmp/wan-4.png" alt="wan-4">
+        <p>
+        <img src="/tmp/wan-5.png" alt="wan-5">
+        <p>
+        <img src="/tmp/wan-6.png" alt="wan-6">
+    </body>
+</html>