/* packet-logcat-text.c
 * Routines for Android Logcat text formats
 *
 * Copyright 2014, Michal Orynicz for Tieto Corporation
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"

#include <stdio.h>      /* for sscanf() */

#include "epan/packet.h"
#include "epan/expert.h"
#include "epan/exported_pdu.h"
#include "epan/tap.h"
#include "wiretap/logcat_text.h"

extern const value_string priority_vals[];

static int proto_logcat_text;

static int hf_logcat_text_pid;
static int hf_logcat_text_tid;
static int hf_logcat_text_timestamp;
static int hf_logcat_text_priority;
static int hf_logcat_text_tag;
static int hf_logcat_text_log;

static int ett_logcat;

static expert_field ei_malformed_time;
static expert_field ei_malformed_token;

static dissector_handle_t logcat_text_brief_handle;
static dissector_handle_t logcat_text_tag_handle;
static dissector_handle_t logcat_text_process_handle;
static dissector_handle_t logcat_text_time_handle;
static dissector_handle_t logcat_text_thread_handle;
static dissector_handle_t logcat_text_threadtime_handle;
static dissector_handle_t logcat_text_long_handle;

static int exported_pdu_tap = -1;

static GRegex *special_regex;
static GRegex *brief_regex;
static GRegex *tag_regex;
static GRegex *time_regex;
static GRegex *process_regex;
static GRegex *thread_regex;
static GRegex *threadtime_regex;
static GRegex *long_regex;

static const char dissector_name[] = "Logcat Text";

typedef int (*tGETTER) (const char *frame, const char *token, tvbuff_t *tvb,
        proto_tree *maintree, int start_offset, packet_info *pinfo);

typedef struct {
    GRegex **regex;
    const tGETTER *getters;
    unsigned no_of_getters;
} dissect_info_t;

void proto_register_logcat_text(void);
void proto_reg_handoff_logcat_text(void);

static int get_priority(const char *frame, const char *token, tvbuff_t *tvb,
        proto_tree *maintree, int start_offset, packet_info *pinfo) {
    int prio;
    char *p = g_strstr_len(frame + start_offset, -1, token);
    int offset = (int)(p - frame);

    if (!p) {
        proto_tree_add_expert(maintree, pinfo, &ei_malformed_token, tvb, start_offset, -1);
        return (start_offset + 1);
    }

    switch (*p) {
    case 'I':
        prio = 4;
        break;
    case 'V':
        prio = 2;
        break;
    case 'D':
        prio = 3;
        break;
    case 'W':
        prio = 5;
        break;
    case 'E':
        prio = 6;
        break;
    case 'F':
        prio = 7;
        break;
    default:
        prio = 0;
    }

    proto_tree_add_uint(maintree, hf_logcat_text_priority, tvb, offset, 1, prio);
    return offset + 1;
}

static int get_tag(const char *frame, const char *token, tvbuff_t *tvb,
        proto_tree *maintree, int start_offset, packet_info *pinfo) {
    char *p = g_strstr_len(frame + start_offset, -1, token);
    int offset = (int)(p - frame);
    uint8_t *src_addr = wmem_strdup(pinfo->pool, token);
    int tok_len = (int)strlen(token);

    proto_tree_add_string(maintree, hf_logcat_text_tag, tvb, offset, tok_len,
            token);
    set_address(&pinfo->src, AT_STRINGZ, tok_len + 1, src_addr);
    set_address(&pinfo->dst, AT_STRINGZ, sizeof(dissector_name), dissector_name);
    return offset + tok_len;
}

static int get_ptid(const char *frame, const char *token, tvbuff_t *tvb,
        proto_tree *maintree, int header_field, int start_offset) {
    char *p = g_strstr_len(frame + start_offset, -1, token);
    int offset = (int)(p - frame);

    proto_tree_add_uint(maintree, header_field, tvb, offset, (int)strlen(token),
            (uint32_t)g_ascii_strtoull(token, NULL, 10));
    return offset + (int)strlen(token);
}

static int get_pid(const char *frame, const char *token, tvbuff_t *tvb,
        proto_tree *maintree, int start_offset, packet_info *pinfo _U_) {
    return get_ptid(frame, token, tvb, maintree, hf_logcat_text_pid, start_offset);
}

static int get_tid(const char *frame, const char *token, tvbuff_t *tvb,
        proto_tree *maintree, int start_offset, packet_info *pinfo _U_) {
    return get_ptid(frame, token, tvb, maintree, hf_logcat_text_tid, start_offset);
}

static int get_log(const char *frame, const char *token, tvbuff_t *tvb,
        proto_tree *maintree, int start_offset, packet_info *pinfo) {
    char *p = g_strstr_len(frame + start_offset, -1, token);
    int offset = (int)(p - frame);

    proto_tree_add_string(maintree, hf_logcat_text_log, tvb, offset,
            (int)strlen(token), token);
    col_add_str(pinfo->cinfo, COL_INFO, token);
    return offset + (int)strlen(token);
}

static int get_time(const char *frame, const char *token, tvbuff_t *tvb,
        proto_tree *maintree, int start_offset, packet_info *pinfo) {
    int offset;
    char *p;
    int ms;
    struct tm date;
    time_t seconds;
    nstime_t ts;

    p = g_strstr_len(frame + start_offset, -1, token);
    offset = (int)(p - frame);

    if (6 == sscanf(token, "%d-%d %d:%d:%d.%d", &date.tm_mon, &date.tm_mday,
                    &date.tm_hour, &date.tm_min, &date.tm_sec, &ms)) {
        date.tm_year = 70;
        date.tm_mon -= 1;
        date.tm_isdst = -1;
        seconds = mktime(&date);
        ts.secs = seconds;
        ts.nsecs = (int) (ms * 1e6);
        proto_tree_add_time(maintree, hf_logcat_text_timestamp, tvb, offset,
                (int)strlen(token), &ts);
    } else {
        proto_tree_add_expert(maintree, pinfo, &ei_malformed_time, tvb, offset, -1);
    }
    return offset + (int)strlen(token);
}

static int dissect_logcat_text(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo,
        const dissect_info_t *dinfo) {
    char **tokens;
    unsigned i;
    char *frame = tvb_get_string_enc(pinfo->pool, tvb, 0, tvb_captured_length(tvb),
            ENC_UTF_8);
    proto_item *mainitem = proto_tree_add_item(tree, proto_logcat_text, tvb, 0, -1, ENC_NA);
    proto_tree *maintree = proto_item_add_subtree(mainitem, ett_logcat);
    int offset = 0;

    col_set_str(pinfo->cinfo, COL_PROTOCOL, dissector_name);

    if (!g_regex_match(special_regex, frame, G_REGEX_MATCH_NOTEMPTY, NULL)) {

        tokens = g_regex_split(*dinfo->regex, frame, G_REGEX_MATCH_NOTEMPTY);
        if (NULL == tokens) return 0;
        if (g_strv_length(tokens) != dinfo->no_of_getters + 2) {
            proto_tree_add_expert(maintree, pinfo, &ei_malformed_token, tvb, offset, -1);
            g_strfreev(tokens);
            return 0;
        }

        for (i = 0; i < dinfo->no_of_getters; ++i) {
            offset = ((*dinfo->getters[i])(frame, tokens[i + 1], tvb, maintree, offset, pinfo));
        }
    } else {
        tokens = g_regex_split(special_regex, frame, G_REGEX_MATCH_NOTEMPTY);
        if (NULL == tokens) return 0;
        offset = get_log(frame, tokens[1], tvb, maintree, 0, pinfo);
    }
    g_strfreev(tokens);
    return offset;
}

static void add_exported_pdu(tvbuff_t *tvb, packet_info *pinfo, const char * subdissector_name){
    if (have_tap_listener(exported_pdu_tap)) {
        exp_pdu_data_t *exp_pdu_data;

        exp_pdu_data = export_pdu_create_tags(pinfo, subdissector_name, EXP_PDU_TAG_DISSECTOR_NAME, NULL);

        exp_pdu_data->tvb_captured_length = tvb_captured_length(tvb);
        exp_pdu_data->tvb_reported_length = tvb_reported_length(tvb);
        exp_pdu_data->pdu_tvb = tvb;
        tap_queue_packet(exported_pdu_tap, pinfo, exp_pdu_data);
    }
}

static int dissect_logcat_text_brief(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
        void *data _U_) {
    static const tGETTER getters[] = { get_priority, get_tag, get_pid, get_log };
    dissect_info_t dinfo = { &brief_regex, getters, array_length(getters) };

    add_exported_pdu(tvb,pinfo,"logcat_text_brief");
    return dissect_logcat_text(tvb, tree, pinfo, &dinfo);
}

static int dissect_logcat_text_tag(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
        void *data _U_) {
    static const tGETTER getters[] = { get_priority, get_tag, get_log };
    dissect_info_t dinfo = { &tag_regex, getters, array_length(getters) };

    add_exported_pdu(tvb,pinfo,"logcat_text_tag");
    return dissect_logcat_text(tvb, tree, pinfo, &dinfo);
}

static int dissect_logcat_text_process(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
        void *data _U_) {
    static const tGETTER getters[] = { get_priority, get_pid, get_log };
    dissect_info_t dinfo = { &process_regex, getters, array_length(getters) };

    add_exported_pdu(tvb,pinfo,"logcat_text_process");
    set_address(&pinfo->dst, AT_STRINGZ, 1, "");
    set_address(&pinfo->src, AT_STRINGZ, 1, "");

    return dissect_logcat_text(tvb, tree, pinfo, &dinfo);
}

static int dissect_logcat_text_time(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
        void *data _U_) {
    static const tGETTER getters[] = { get_time, get_priority, get_tag, get_pid, get_log };
    dissect_info_t dinfo = { &time_regex, getters, array_length(getters) };

    add_exported_pdu(tvb,pinfo,"logcat_text_time");
    return dissect_logcat_text(tvb, tree, pinfo, &dinfo);
}

static int dissect_logcat_text_thread(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
        void *data _U_) {
    static const tGETTER getters[] = { get_priority, get_pid, get_tid, get_log };
    dissect_info_t dinfo = { &thread_regex, getters, array_length(getters) };

    add_exported_pdu(tvb,pinfo,"logcat_text_brief");
    set_address(&pinfo->dst, AT_STRINGZ, 1, "");
    set_address(&pinfo->src, AT_STRINGZ, 1, "");

    return dissect_logcat_text(tvb, tree, pinfo, &dinfo);
}

static int dissect_logcat_text_threadtime(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
        void *data _U_) {
    static const tGETTER getters[] = { get_time, get_pid, get_tid, get_priority, get_tag, get_log };
    dissect_info_t dinfo = { &threadtime_regex, getters, array_length(getters) };

    add_exported_pdu(tvb,pinfo,"logcat_text_threadtime");
    return dissect_logcat_text(tvb, tree, pinfo, &dinfo);
}

static int dissect_logcat_text_long(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
        void *data _U_) {
    static const tGETTER getters[] = { get_time, get_pid, get_tid, get_priority, get_tag, get_log };
    dissect_info_t dinfo = { &long_regex, getters, array_length(getters) };

    add_exported_pdu(tvb,pinfo,"logcat_text_long");
    return dissect_logcat_text(tvb, tree, pinfo, &dinfo);
}

static void logcat_text_init(void)
{
    special_regex =    g_regex_new(SPECIAL_STRING,    (GRegexCompileFlags)(G_REGEX_ANCHORED | G_REGEX_OPTIMIZE | G_REGEX_RAW),  G_REGEX_MATCH_NOTEMPTY, NULL);
    brief_regex =      g_regex_new(BRIEF_STRING,      (GRegexCompileFlags)(G_REGEX_ANCHORED | G_REGEX_OPTIMIZE | G_REGEX_RAW),  G_REGEX_MATCH_NOTEMPTY, NULL);
    tag_regex =        g_regex_new(TAG_STRING,        (GRegexCompileFlags)(G_REGEX_ANCHORED | G_REGEX_OPTIMIZE | G_REGEX_RAW),  G_REGEX_MATCH_NOTEMPTY, NULL);
    time_regex =       g_regex_new(TIME_STRING,       (GRegexCompileFlags)(G_REGEX_ANCHORED | G_REGEX_OPTIMIZE | G_REGEX_RAW),  G_REGEX_MATCH_NOTEMPTY, NULL);
    thread_regex =     g_regex_new(THREAD_STRING,     (GRegexCompileFlags)(G_REGEX_ANCHORED | G_REGEX_OPTIMIZE | G_REGEX_RAW),  G_REGEX_MATCH_NOTEMPTY, NULL);
    threadtime_regex = g_regex_new(THREADTIME_STRING, (GRegexCompileFlags)(G_REGEX_ANCHORED | G_REGEX_OPTIMIZE | G_REGEX_RAW),  G_REGEX_MATCH_NOTEMPTY, NULL);
    process_regex =    g_regex_new(PROCESS_STRING,    (GRegexCompileFlags)(G_REGEX_ANCHORED | G_REGEX_OPTIMIZE | G_REGEX_RAW),  G_REGEX_MATCH_NOTEMPTY, NULL);
    long_regex =       g_regex_new(LONG_STRING,       (GRegexCompileFlags)(G_REGEX_MULTILINE | G_REGEX_OPTIMIZE | G_REGEX_RAW), G_REGEX_MATCH_NOTEMPTY, NULL);
}

static void logcat_text_cleanup(void)
{
    g_regex_unref(special_regex);
    g_regex_unref(brief_regex);
    g_regex_unref(tag_regex);
    g_regex_unref(time_regex);
    g_regex_unref(thread_regex);
    g_regex_unref(threadtime_regex);
    g_regex_unref(process_regex);
    g_regex_unref(long_regex);
}

void proto_register_logcat_text(void) {
    expert_module_t  *expert_module;
    static hf_register_info hf[] = {
            { &hf_logcat_text_timestamp,
                { "Timestamp", "logcat_text.timestamp",
                FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x00, NULL, HFILL
                }
            },
            { &hf_logcat_text_tag,
                { "Tag",       "logcat_text.tag",
                FT_STRING, BASE_NONE, NULL, 0x00, NULL, HFILL
                }
            },
            { &hf_logcat_text_log,
                { "Log",       "logcat_text.log",
                FT_STRING, BASE_NONE, NULL, 0x00, NULL, HFILL
                }
            },
            { &hf_logcat_text_priority,
                { "Priority",  "logcat_text.priority",
                FT_UINT8, BASE_DEC, VALS(priority_vals), 0x00, NULL, HFILL
                }
            },
            { &hf_logcat_text_pid,
                { "PID",       "logcat_text.pid",
                FT_UINT32, BASE_DEC, NULL, 0x00, "Process ID", HFILL
                }
            },
            { &hf_logcat_text_tid,
                { "TID",       "logcat_text.tid",
                FT_UINT32, BASE_DEC, NULL, 0x00, "Thread ID", HFILL
                }
            }
    };

    static ei_register_info ei[] = {
            { &ei_malformed_time,  { "logcat_text.malformed_time", PI_PROTOCOL, PI_ERROR, "Malformed time data", EXPFILL }},
            { &ei_malformed_token, { "logcat_text.malformed_token", PI_PROTOCOL, PI_ERROR, "Failed to decode one or more tokens", EXPFILL }},
    };

    static int *ett[] = { &ett_logcat};

    proto_logcat_text = proto_register_protocol("Android Logcat Text", dissector_name,
            "logcat_text");
    proto_register_field_array(proto_logcat_text, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));

    logcat_text_brief_handle =      register_dissector("logcat_text_brief",
            dissect_logcat_text_brief, proto_logcat_text);
    logcat_text_tag_handle =        register_dissector("logcat_text_tag",
            dissect_logcat_text_tag, proto_logcat_text);
    logcat_text_time_handle =       register_dissector("logcat_text_time",
            dissect_logcat_text_time, proto_logcat_text);
    logcat_text_process_handle =    register_dissector("logcat_text_process",
            dissect_logcat_text_process, proto_logcat_text);
    logcat_text_thread_handle =     register_dissector("logcat_text_thread",
            dissect_logcat_text_thread, proto_logcat_text);
    logcat_text_threadtime_handle = register_dissector("logcat_text_threadtime",
            dissect_logcat_text_threadtime, proto_logcat_text);
    logcat_text_long_handle =       register_dissector("logcat_text_long",
            dissect_logcat_text_long, proto_logcat_text);

    register_init_routine(logcat_text_init);
    register_cleanup_routine(logcat_text_cleanup);

    expert_module = expert_register_protocol(proto_logcat_text);
    expert_register_field_array(expert_module, ei, array_length(ei));

    exported_pdu_tap = register_export_pdu_tap("Logcat Text");
}

void proto_reg_handoff_logcat_text(void) {
    dissector_add_uint("wtap_encap", WTAP_ENCAP_LOGCAT_BRIEF,
            logcat_text_brief_handle);
    dissector_add_uint("wtap_encap", WTAP_ENCAP_LOGCAT_TAG,
            logcat_text_tag_handle);
    dissector_add_uint("wtap_encap", WTAP_ENCAP_LOGCAT_TIME,
            logcat_text_time_handle);
    dissector_add_uint("wtap_encap", WTAP_ENCAP_LOGCAT_THREAD,
            logcat_text_thread_handle);
    dissector_add_uint("wtap_encap", WTAP_ENCAP_LOGCAT_THREADTIME,
            logcat_text_threadtime_handle);
    dissector_add_uint("wtap_encap", WTAP_ENCAP_LOGCAT_PROCESS,
            logcat_text_process_handle);
    dissector_add_uint("wtap_encap", WTAP_ENCAP_LOGCAT_LONG,
            logcat_text_long_handle);
}

/*
 * Editor modelines  -  https://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:
 */
