/* tap-icmpstat.c * icmpstat 2011 Christopher Maynard * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0+*/ /* This module provides icmp echo request/reply SRT statistics to tshark. * It is only used by tshark and not wireshark * * It was based on tap-rpcstat.c and doc/README.tapping. */ #include "config.h" #include #include #include #include #include #include #include #include #include void register_tap_listener_icmpstat(void); /* used to keep track of the ICMP statistics */ typedef struct _icmpstat_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; } icmpstat_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 icmpstat_reset(void *tapdata) { icmpstat_t *icmpstat = (icmpstat_t *)tapdata; g_slist_free(icmpstat->rt_list); memset(icmpstat, 0, sizeof(icmpstat_t)); icmpstat->min_msecs = 1.0 * G_MAXUINT; } static gint compare_doubles(gconstpointer a, gconstpointer b) { double ad, bd; ad = *(const double *)a; bd = *(const 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 * "icmp" tap, the third parameter type is icmp_transaction_t. * * function returns : * FALSE: no updates, no need to call (*draw) later * TRUE: state has changed, call (*draw) sometime later */ static gboolean icmpstat_packet(void *tapdata, packet_info *pinfo _U_, epan_dissect_t *edt _U_, const void *data) { icmpstat_t *icmpstat = (icmpstat_t *)tapdata; const icmp_transaction_t *trans = (const icmp_transaction_t *)data; double resp_time, *rt; if (trans == NULL) return FALSE; if (trans->resp_frame) { resp_time = nstime_to_msec(&trans->resp_time); rt = g_new(double, 1); if (rt == NULL) return FALSE; *rt = resp_time; icmpstat->rt_list = g_slist_prepend(icmpstat->rt_list, rt); icmpstat->num_resps++; if (icmpstat->min_msecs > resp_time) { icmpstat->min_frame = trans->resp_frame; icmpstat->min_msecs = resp_time; } if (icmpstat->max_msecs < resp_time) { icmpstat->max_frame = trans->resp_frame; icmpstat->max_msecs = resp_time; } icmpstat->tot_msecs += resp_time; } else if (trans->rqst_frame) icmpstat->num_rqsts++; else return FALSE; return TRUE; } /* * Compute the mean, median and standard deviation. */ static void compute_stats(icmpstat_t *icmpstat, double *mean, double *med, double *sdev) { GSList *slist; double diff; double sq_diff_sum = 0.0; icmpstat->rt_list = g_slist_sort(icmpstat->rt_list, compare_doubles); slist = icmpstat->rt_list; if (icmpstat->num_resps == 0 || slist == NULL) { *mean = 0.0; *med = 0.0; *sdev = 0.0; return; } /* (arithmetic) mean */ *mean = icmpstat->tot_msecs / icmpstat->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 (icmpstat->num_resps & 1) *med = *(double *)g_slist_nth_data(slist, icmpstat->num_resps / 2); else { *med = (*(double *)g_slist_nth_data(slist, (icmpstat->num_resps - 1) / 2) + *(double *)g_slist_nth_data(slist, icmpstat->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 (icmpstat->num_resps > 1) *sdev = sqrt(sq_diff_sum / (icmpstat->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 icmpstat_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 icmpstat_draw(void *tapdata) { icmpstat_t *icmpstat = (icmpstat_t *)tapdata; unsigned int lost; double mean, sdev, med; printf("\n"); printf("==========================================================================\n"); printf("ICMP Service Response Time (SRT) Statistics (all times in ms):\n"); printf("Filter: %s\n", icmpstat->filter ? icmpstat->filter : ""); printf("\nRequests Replies Lost %% Loss\n"); if (icmpstat->num_rqsts) { lost = icmpstat->num_rqsts - icmpstat->num_resps; compute_stats(icmpstat, &mean, &med, &sdev); printf("%-10u%-10u%-10u%5.1f%%\n\n", icmpstat->num_rqsts, icmpstat->num_resps, lost, 100.0 * lost / icmpstat->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", icmpstat->min_msecs >= G_MAXUINT ? 0.0 : icmpstat->min_msecs, icmpstat->max_msecs, mean, med, sdev, icmpstat->min_frame, icmpstat->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 icmpstat. * * This function is called from tshark when it parses the -z icmp, arguments * and it creates a new instance to store statistics in and registers this new * instance for the icmp tap. */ static void icmpstat_init(const char *opt_arg, void *userdata _U_) { icmpstat_t *icmpstat; const char *filter = NULL; GString *error_string; if (strstr(opt_arg, "icmp,srt,")) filter = opt_arg + strlen("icmp,srt,"); icmpstat = (icmpstat_t *)g_try_malloc(sizeof(icmpstat_t)); if (icmpstat == NULL) { fprintf(stderr, "tshark: g_try_malloc() fatal error.\n"); exit(1); } memset(icmpstat, 0, sizeof(icmpstat_t)); icmpstat->min_msecs = 1.0 * G_MAXUINT; icmpstat->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("icmp", icmpstat, icmpstat->filter, TL_REQUIRES_NOTHING, icmpstat_reset, icmpstat_packet, icmpstat_draw); if (error_string) { /* error, we failed to attach to the tap. clean up */ g_free(icmpstat->filter); g_free(icmpstat); fprintf(stderr, "tshark: Couldn't register icmp,srt tap: %s\n", error_string->str); g_string_free(error_string, TRUE); exit(1); } } static stat_tap_ui icmpstat_ui = { REGISTER_STAT_GROUP_GENERIC, NULL, "icmp,srt", icmpstat_init, 0, NULL }; void register_tap_listener_icmpstat(void) { register_stat_tap_ui(&icmpstat_ui, NULL); } /* * Editor modelines - http://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 4 * tab-width: 8 * indent-tabs-mode: nil * End: * * vi: set shiftwidth=4 tabstop=8 expandtab: * :indentSize=4:tabSize=8:noTabs=true: */