/* tap-icmpv6stat.c * icmpv6stat 2011 Christopher Maynard * * $Id$ * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* This module provides icmpv6 echo request/reply SRT statistics to tshark. * It is only used by tshark and not wireshark * * It was based on tap-icmptat.c, which itself was based on tap-rpcstat.c and * doc/README.tapping. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #ifdef HAVE_SYS_TYPES_H # include #endif #include #include "epan/packet_info.h" #include #include #include #include /* used to keep track of the ICMPv6 statistics */ typedef struct _icmpv6stat_t { char *filter; GSList *rt_list; guint num_rqsts; guint num_resps; guint min_frame; guint max_frame; double min_msecs; double max_msecs; double tot_msecs; } icmpv6stat_t; /* This callback is never used by tshark but it is here for completeness. When * registering below, we could just have left this function as NULL. * * When used by wireshark, this function will be called whenever we would need * to reset all state, such as when wireshark opens a new file, when it starts * a new capture, when it rescans the packetlist after some prefs have changed, * etc. * * So if your application has some state it needs to clean up in those * situations, here is a good place to put that code. */ static void icmpv6stat_reset(void *tapdata) { icmpv6stat_t *icmpv6stat = tapdata; g_slist_free(icmpv6stat->rt_list); memset(icmpv6stat, 0, sizeof(icmpv6stat_t)); icmpv6stat->min_msecs = 1.0 * G_MAXUINT; } static gint compare_doubles(gconstpointer a, gconstpointer b) { double ad, bd; ad = *(double *)a; bd = *(double *)b; if (ad < bd) return -1; if (ad > bd) return 1; return 0; } /* This callback is invoked whenever the tap system has seen a packet we might * be interested in. The function is to be used to only update internal state * information in the *tapdata structure, and if there were state changes which * requires the window to be redrawn, return 1 and (*draw) will be called * sometime later. * * This function should be as lightweight as possible since it executes * together with the normal wireshark dissectors. Try to push as much * processing as possible into (*draw) instead since that function executes * asynchronously and does not affect the main thread's performance. * * If it is possible, try to do all "filtering" explicitly since you will get * MUCH better performance than applying a similar display-filter in the * register call. * * The third parameter is tap dependent. Since we register this one to the * "icmpv6" tap, the third parameter type is icmp_transaction_t. * * function returns : * 0: no updates, no need to call (*draw) later * !0: state has changed, call (*draw) sometime later */ static int icmpv6stat_packet(void *tapdata, packet_info *pinfo _U_, epan_dissect_t *edt _U_, const void *data) { icmpv6stat_t *icmpv6stat = tapdata; const icmp_transaction_t *trans = data; double *rt; if (trans == NULL) return 0; if (trans->resp_frame) { rt = g_malloc(sizeof(double)); if (rt == NULL) return 0; *rt = trans->resp_time; icmpv6stat->rt_list = g_slist_insert_sorted(icmpv6stat->rt_list, rt, compare_doubles); icmpv6stat->num_resps++; if (icmpv6stat->min_msecs > trans->resp_time) { icmpv6stat->min_frame = trans->resp_frame; icmpv6stat->min_msecs = trans->resp_time; } if (icmpv6stat->max_msecs < trans->resp_time) { icmpv6stat->max_frame = trans->resp_frame; icmpv6stat->max_msecs = trans->resp_time; } icmpv6stat->tot_msecs += trans->resp_time; } else if (trans->rqst_frame) icmpv6stat->num_rqsts++; else return 0; return 1; } /* * Compute the mean, median and standard deviation. */ static void compute_stats(icmpv6stat_t *icmpv6stat, double *mean, double *med, double *sdev) { GSList *slist = icmpv6stat->rt_list; double diff; double sq_diff_sum = 0.0; if (icmpv6stat->num_resps == 0 || slist == NULL) { *mean = 0.0; *med = 0.0; *sdev = 0.0; return; } /* (arithmetic) mean */ *mean = icmpv6stat->tot_msecs / icmpv6stat->num_resps; /* median: If we have an odd number of elements in our list, then the * median is simply the middle element, otherwise the median is computed by * averaging the 2 elements on either side of the mid-point. */ if (icmpv6stat->num_resps & 1) *med = *(double *)g_slist_nth_data(slist, icmpv6stat->num_resps / 2); else { *med = (*(double *)g_slist_nth_data(slist, (icmpv6stat->num_resps - 1) / 2) + *(double *)g_slist_nth_data(slist, icmpv6stat->num_resps / 2)) / 2; } /* (sample) standard deviation */ for ( ; slist; slist = g_slist_next(slist)) { diff = *(double *)slist->data - *mean; sq_diff_sum += diff * diff; } if (icmpv6stat->num_resps > 1) *sdev = sqrt(sq_diff_sum / (icmpv6stat->num_resps - 1)); else *sdev = 0.0; } /* This callback is used when tshark wants us to draw/update our data to the * output device. Since this is tshark, the only output is stdout. * TShark will only call this callback once, which is when tshark has finished * reading all packets and exits. * If used with wireshark this may be called any time, perhaps once every 3 * seconds or so. * This function may even be called in parallel with (*reset) or (*draw), so * make sure there are no races. The data in the icmpv6stat_t can thus change * beneath us. Beware! * * How best to display the data? For now, following other tap statistics * output, but here are a few other alternatives we might choose from: * * -> Windows ping output: * Ping statistics for : * Packets: Sent = , Received = , Lost = (% loss), * Approximate round trip times in milli-seconds: * Minimum = ms, Maximum = ms, Average = ms * * -> Cygwin ping output: * ---- PING Statistics---- * packets transmitted, packets received, % packet loss * round-trip (ms) min/avg/max/med = /// * * -> Linux ping output: * --- ping statistics --- * packets transmitted, received, % packet loss, time ms * rtt min/avg/max/mdev = /// ms */ static void icmpv6stat_draw(void *tapdata) { icmpv6stat_t *icmpv6stat = tapdata; unsigned int lost; double mean, sdev, med; printf("\n"); printf("==========================================================================\n"); printf("ICMPv6 Service Response Time (SRT) Statistics (all times in ms):\n"); printf("Filter: %s\n", icmpv6stat->filter ? icmpv6stat->filter : ""); printf("\nRequests Replies Lost %% Loss\n"); if (icmpv6stat->num_rqsts) { lost = icmpv6stat->num_rqsts - icmpv6stat->num_resps; compute_stats(icmpv6stat, &mean, &med, &sdev); printf("%-10u%-10u%-10u%5.1f%%\n\n", icmpv6stat->num_rqsts, icmpv6stat->num_resps, lost, 100.0 * lost / icmpv6stat->num_rqsts); printf("Minimum Maximum Mean Median SDeviation Min Frame Max Frame\n"); printf("%-10.3f%-10.3f%-10.3f%-10.3f%-10.3f %-10u%-10u\n", icmpv6stat->min_msecs >= G_MAXUINT ? 0.0 : icmpv6stat->min_msecs, icmpv6stat->max_msecs, mean, med, sdev, icmpv6stat->min_frame, icmpv6stat->max_frame); } else { printf("0 0 0 0.0%%\n\n"); printf("Minimum Maximum Mean Median SDeviation Min Frame Max Frame\n"); printf("0.000 0.000 0.000 0.000 0.000 0 0\n"); } printf("==========================================================================\n"); } /* When called, this function will create a new instance of icmpv6stat. * * This function is called from tshark when it parses the -z icmpv6, arguments * and it creates a new instance to store statistics in and registers this new * instance for the icmpv6 tap. */ static void icmpv6stat_init(const char *optarg, void* userdata _U_) { icmpv6stat_t *icmpv6stat; const char *filter = NULL; GString *error_string; if (strstr(optarg, "icmpv6,srt,")) filter = optarg + strlen("icmpv6,srt,"); icmpv6stat = g_try_malloc(sizeof(icmpv6stat_t)); if (icmpv6stat == NULL) { fprintf(stderr, "tshark: g_try_malloc() fatal error.\n"); exit(1); } memset(icmpv6stat, 0, sizeof(icmpv6stat_t)); icmpv6stat->min_msecs = 1.0 * G_MAXUINT; if (filter) icmpv6stat->filter = g_strdup(filter); /* It is possible to create a filter and attach it to the callbacks. Then the * callbacks would only be invoked if the filter matched. * * Evaluating filters is expensive and if we can avoid it and not use them, * then we gain performance. * * In this case we do the filtering for protocol and version inside the * callback itself but use whatever filter the user provided. */ error_string = register_tap_listener("icmpv6", icmpv6stat, icmpv6stat->filter, TL_REQUIRES_NOTHING, icmpv6stat_reset, icmpv6stat_packet, icmpv6stat_draw); if (error_string) { /* error, we failed to attach to the tap. clean up */ if (icmpv6stat->filter) g_free(icmpv6stat->filter); g_free(icmpv6stat); fprintf(stderr, "tshark: Couldn't register icmpv6,srt tap: %s\n", error_string->str); g_string_free(error_string, TRUE); exit(1); } } void register_tap_listener_icmpv6stat(void) { register_stat_cmd_arg("icmpv6,srt", icmpv6stat_init, NULL); }