res_pjsip_logger.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * Mark Michelson <mmichelson@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */
 
/*** MODULEINFO
    <depend>pjproject</depend>
    <depend>res_pjsip</depend>
    <defaultenabled>yes</defaultenabled>
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include <netinet/in.h> /* For IPPROTO_UDP and in6_addr */
 
#include <pjsip.h>
 
#include "asterisk/res_pjsip.h"
#include "asterisk/vector.h"
#include "asterisk/module.h"
#include "asterisk/logger.h"
#include "asterisk/cli.h"
#include "asterisk/netsock2.h"
#include "asterisk/acl.h"
 
/*! \brief PCAP Header */
struct pcap_header {
    uint32_t magic_number;  /*! \brief PCAP file format magic number */
    uint16_t version_major; /*! \brief Major version number of the file format */
    uint16_t version_minor; /*! \brief Minor version number of the file format */
    int32_t thiszone;   /*! \brief GMT to local correction */
    uint32_t sigfigs;   /*! \brief Accuracy of timestamps */
    uint32_t snaplen;   /*! \brief The maximum size that can be recorded in the file */
    uint32_t network;   /*! \brief Type of packets held within the file */
};
 
/*! \brief PCAP Packet Record Header */
struct pcap_record_header {
    uint32_t ts_sec;    /*! \brief When the record was created */
    uint32_t ts_usec;   /*! \brief When the record was created */
    uint32_t incl_len;  /*! \brief Length of packet as saved in the file */
    uint32_t orig_len;  /*! \brief Length of packet as sent over network */
};
 
/*! \brief PCAP Ethernet Header */
struct pcap_ethernet_header {
    uint8_t dst[6]; /*! \brief Destination MAC address */
    uint8_t src[6]; /*! \brief Source MAD address */
    uint16_t type;  /*! \brief The type of packet contained within */
} __attribute__((__packed__));
 
/*! \brief PCAP IPv4 Header */
struct pcap_ipv4_header {
    uint8_t ver_ihl;    /*! \brief IP header version and other bits */
    uint8_t ip_tos;     /*! \brief Type of service details */
    uint16_t ip_len;    /*! \brief Total length of the packet (including IPv4 header) */
    uint16_t ip_id;     /*! \brief Identification value */
    uint16_t ip_off;    /*! \brief Fragment offset */
    uint8_t ip_ttl;     /*! \brief Time to live for the packet */
    uint8_t ip_protocol;    /*! \brief Protocol of the data held within the packet (always UDP) */
    uint16_t ip_sum;    /*! \brief Checksum (not calculated for our purposes */
    uint32_t ip_src;    /*! \brief Source IP address */
    uint32_t ip_dst;    /*! \brief Destination IP address */
};
 
/*! \brief PCAP IPv6 Header */
struct pcap_ipv6_header {
   union {
      struct ip6_hdrctl {
         uint32_t ip6_un1_flow; /*! \brief Version, traffic class, flow label */
         uint16_t ip6_un1_plen; /*! \brief Length of the packet (not including IPv6 header) */
         uint8_t ip6_un1_nxt;   /*! \brief Next header field */
         uint8_t ip6_un1_hlim;  /*! \brief Hop Limit */
      } ip6_un1;
      uint8_t ip6_un2_vfc;  /*! \brief Version, traffic class */
   } ip6_ctlun;
   struct in6_addr ip6_src; /*! \brief Source IP address */
   struct in6_addr ip6_dst; /*! \brief Destination IP address */
};
 
/*! \brief PCAP UDP Header */
struct pcap_udp_header {
    uint16_t src;       /*! \brief Source IP port */
    uint16_t dst;       /*! \brief Destination IP port */
    uint16_t length;    /*! \brief Length of the UDP header plus UDP packet */
    uint16_t checksum;  /*! \brief Packet checksum, left uncalculated for our purposes */
};
 
struct method_logging_info {
    pj_str_t pj_name;    /*! \brief A PJSIP string for the method */
    pjsip_method method; /*! \brief The PJSIP method structure used for comparisons */
    char name[];         /*! \brief The method name */
};
 
/*! \brief PJSIP Logging Session */
struct pjsip_logger_session {
    /*! \brief Explicit addresses or ranges being logged */
    struct ast_ha *matches;
    /*! \brief Filename used for the pcap file */
    char pcap_filename[PATH_MAX];
    /*! \brief The pcap file itself */
    FILE *pcap_file;
    /*! \brief Whether the session is enabled or not */
    unsigned int enabled:1;
    /*! \brief Whether the session is logging all traffic or not */
    unsigned int log_all_traffic:1;
    /*! \brief Whether to log to verbose or not */
    unsigned int log_to_verbose:1;
    /*! \brief Whether to log to pcap or not */
    unsigned int log_to_pcap:1;
    /*! \brief Vector of SIP methods to log */
    AST_VECTOR(, struct method_logging_info *) log_methods;
};
 
/*! \brief The default logger session */
static struct pjsip_logger_session *default_logger;
 
/*! \brief Destructor for logger session */
static void pjsip_logger_session_destroy(void *obj)
{
    struct pjsip_logger_session *session = obj;
 
    if (session->pcap_file) {
        fclose(session->pcap_file);
    }
 
    ast_free_ha(session->matches);
 
    AST_VECTOR_RESET(&session->log_methods, ast_free);
    AST_VECTOR_FREE(&session->log_methods);
}
 
/*! \brief Allocator for logger session */
static struct pjsip_logger_session *pjsip_logger_session_alloc(void)
{
    struct pjsip_logger_session *session;
 
    session = ao2_alloc_options(sizeof(struct pjsip_logger_session), pjsip_logger_session_destroy,
        AO2_ALLOC_OPT_LOCK_RWLOCK);
    if (!session) {
        return NULL;
    }
 
    session->log_to_verbose = 1;
 
    AST_VECTOR_INIT(&session->log_methods, 0);
 
    return session;
}
 
/*! \note Must be called with the pjsip_logger_session lock held */
static int apply_method_filter(const struct pjsip_logger_session *session, const pjsip_method *method)
{
    size_t size = AST_VECTOR_SIZE(&session->log_methods);
    size_t i;
 
    if (size == 0) {
        /* Nothing in the vector means everything matches */
        return 0;
    }
 
    for (i = 0; i < size; ++i) {
        struct method_logging_info *candidate = AST_VECTOR_GET(&session->log_methods, i);
        if (pjsip_method_cmp(&candidate->method, method) == 0) {
            return 0;
        }
    }
 
    /* Nothing matched */
    return 1;
}
 
/*! \brief See if we pass debug filter */
static inline int pjsip_log_test_filter(const struct pjsip_logger_session *session, const char *address, int port, const pjsip_method *method)
{
    struct ast_sockaddr test_addr;
 
    if (!session->enabled) {
        return 0;
    }
 
    if (session->log_all_traffic) {
        return 1;
    }
 
    if (apply_method_filter(session, method)) {
        /* The method filter didn't match anything, so reject. */
        return 0;
    }
 
    /* A null address was passed in or no explicit matches. Just reject it. */
    if (ast_strlen_zero(address) || !session->matches) {
        /* If we matched on method and host is empty, accept, otherwise reject. */
        return AST_VECTOR_SIZE(&session->log_methods) > 0;
    }
 
    ast_sockaddr_parse(&test_addr, address, PARSE_PORT_IGNORE);
    ast_sockaddr_set_port(&test_addr, port);
 
    /* Compare the address against the matches */
    if (ast_apply_ha(session->matches, &test_addr) != AST_SENSE_ALLOW) {
        return 1;
    } else {
        return 0;
    }
}
 
static void pjsip_logger_write_to_pcap(struct pjsip_logger_session *session, const char *msg, size_t msg_len,
    pj_sockaddr *source, pj_sockaddr *destination)
{
    struct timeval now = ast_tvnow();
    struct pcap_record_header pcap_record_header = {
        .ts_sec = now.tv_sec,
        .ts_usec = now.tv_usec,
    };
    struct pcap_ethernet_header pcap_ethernet_header = {
        .type = 0,
    };
    struct pcap_ipv4_header pcap_ipv4_header = {
        .ver_ihl = 0x45, /* IPv4 + 20 bytes of header */
        .ip_ttl = 128, /* We always put a TTL of 128 to keep Wireshark less blue */
    };
    struct pcap_ipv6_header pcap_ipv6_header = {
        .ip6_ctlun.ip6_un2_vfc = 0x60,
    };
    void *pcap_ip_header;
    size_t pcap_ip_header_len;
    struct pcap_udp_header pcap_udp_header;
 
    /* Packets are always stored as UDP to simplify this logic */
    if (source) {
        pcap_udp_header.src = ntohs(pj_sockaddr_get_port(source));
    } else {
        pcap_udp_header.src = ntohs(0);
    }
    if (destination) {
        pcap_udp_header.dst = ntohs(pj_sockaddr_get_port(destination));
    } else {
        pcap_udp_header.dst = ntohs(0);
    }
    pcap_udp_header.length = ntohs(sizeof(struct pcap_udp_header) + msg_len);
 
    /* Construct the appropriate IP header */
    if ((source && source->addr.sa_family == pj_AF_INET()) ||
        (destination && destination->addr.sa_family == pj_AF_INET())) {
        pcap_ethernet_header.type = htons(0x0800); /* We are providing an IPv4 packet */
        pcap_ip_header = &pcap_ipv4_header;
        pcap_ip_header_len = sizeof(struct pcap_ipv4_header);
        if (source) {
            memcpy(&pcap_ipv4_header.ip_src, pj_sockaddr_get_addr(source), pj_sockaddr_get_addr_len(source));
        }
        if (destination) {
            memcpy(&pcap_ipv4_header.ip_dst, pj_sockaddr_get_addr(destination), pj_sockaddr_get_addr_len(destination));
        }
        pcap_ipv4_header.ip_len = htons(sizeof(struct pcap_udp_header) + sizeof(struct pcap_ipv4_header) + msg_len);
        pcap_ipv4_header.ip_protocol = IPPROTO_UDP; /* We always provide UDP */
    } else {
        pcap_ethernet_header.type = htons(0x86DD); /* We are providing an IPv6 packet */
        pcap_ip_header = &pcap_ipv6_header;
        pcap_ip_header_len = sizeof(struct pcap_ipv6_header);
        if (source) {
            memcpy(&pcap_ipv6_header.ip6_src, pj_sockaddr_get_addr(source), pj_sockaddr_get_addr_len(source));
        }
        if (destination) {
            memcpy(&pcap_ipv6_header.ip6_dst, pj_sockaddr_get_addr(destination), pj_sockaddr_get_addr_len(destination));
        }
        pcap_ipv6_header.ip6_ctlun.ip6_un1.ip6_un1_plen = htons(sizeof(struct pcap_udp_header) + msg_len);
        pcap_ipv6_header.ip6_ctlun.ip6_un1.ip6_un1_nxt = IPPROTO_UDP;
    }
 
    /* Add up all the sizes for this record */
    pcap_record_header.incl_len = pcap_record_header.orig_len = sizeof(pcap_ethernet_header) + pcap_ip_header_len + sizeof(pcap_udp_header) + msg_len;
 
    /* We lock the logger session since we're writing these out in parts */
    ao2_wrlock(session);
    if (session->pcap_file) {
        if (fwrite(&pcap_record_header, sizeof(struct pcap_record_header), 1, session->pcap_file) != 1) {
            ast_log(LOG_WARNING, "Writing PCAP header failed: %s\n", strerror(errno));
        }
        if (fwrite(&pcap_ethernet_header, sizeof(struct pcap_ethernet_header), 1, session->pcap_file) != 1) {
            ast_log(LOG_WARNING, "Writing ethernet header to pcap failed: %s\n", strerror(errno));
        }
        if (fwrite(pcap_ip_header, pcap_ip_header_len, 1, session->pcap_file) != 1) {
            ast_log(LOG_WARNING, "Writing IP header to pcap failed: %s\n", strerror(errno));
        }
        if (fwrite(&pcap_udp_header, sizeof(struct pcap_udp_header), 1, session->pcap_file) != 1) {
            ast_log(LOG_WARNING, "Writing UDP header to pcap failed: %s\n", strerror(errno));
        }
        if (fwrite(msg, msg_len, 1, session->pcap_file) != 1) {
            ast_log(LOG_WARNING, "Writing UDP payload to pcap failed: %s\n", strerror(errno));
        }
    }
    ao2_unlock(session);
}
 
static pj_status_t logging_on_tx_msg(pjsip_tx_data *tdata)
{
    char buffer[AST_SOCKADDR_BUFLEN];
 
    ao2_rdlock(default_logger);
    if (!pjsip_log_test_filter(default_logger, tdata->tp_info.dst_name, tdata->tp_info.dst_port, &tdata->msg->line.req.method)) {
        ao2_unlock(default_logger);
        return PJ_SUCCESS;
    }
    ao2_unlock(default_logger);
 
    if (default_logger->log_to_verbose) {
        ast_verbose("<--- Transmitting SIP %s (%d bytes) to %s:%s --->\n%.*s\n",
            tdata->msg->type == PJSIP_REQUEST_MSG ? "request" : "response",
            (int) (tdata->buf.cur - tdata->buf.start),
            tdata->tp_info.transport->type_name,
            pj_sockaddr_print(&tdata->tp_info.dst_addr, buffer, sizeof(buffer), 3),
            (int) (tdata->buf.end - tdata->buf.start), tdata->buf.start);
    }
 
    if (default_logger->log_to_pcap) {
        pjsip_logger_write_to_pcap(default_logger, tdata->buf.start, (int) (tdata->buf.cur - tdata->buf.start),
            NULL, &tdata->tp_info.dst_addr);
    }
 
    return PJ_SUCCESS;
}
 
static pj_bool_t logging_on_rx_msg(pjsip_rx_data *rdata)
{
    char buffer[AST_SOCKADDR_BUFLEN];
 
    if (!rdata->msg_info.msg) {
        return PJ_FALSE;
    }
 
    ao2_rdlock(default_logger);
    if (!pjsip_log_test_filter(default_logger, rdata->pkt_info.src_name, rdata->pkt_info.src_port, &rdata->msg_info.msg->line.req.method)) {
        ao2_unlock(default_logger);
        return PJ_FALSE;
    }
    ao2_unlock(default_logger);
 
    if (default_logger->log_to_verbose) {
        ast_verbose("<--- Received SIP %s (%d bytes) from %s:%s --->\n%s\n",
            rdata->msg_info.msg->type == PJSIP_REQUEST_MSG ? "request" : "response",
            rdata->msg_info.len,
            rdata->tp_info.transport->type_name,
            pj_sockaddr_print(&rdata->pkt_info.src_addr, buffer, sizeof(buffer), 3),
            rdata->pkt_info.packet);
    }
 
    if (default_logger->log_to_pcap) {
        pjsip_logger_write_to_pcap(default_logger, rdata->pkt_info.packet, rdata->msg_info.len,
            &rdata->pkt_info.src_addr, NULL);
    }
 
    return PJ_FALSE;
}
 
static pjsip_module logging_module = {
    .name = { "Logging Module", 14 },
    .priority = 0,
    .on_rx_request = logging_on_rx_msg,
    .on_rx_response = logging_on_rx_msg,
    .on_tx_request = logging_on_tx_msg,
    .on_tx_response = logging_on_tx_msg,
};
 
static char *pjsip_enable_logger_all(int fd)
{
    ao2_wrlock(default_logger);
    default_logger->enabled = 1;
    default_logger->log_all_traffic = 1;
    ao2_unlock(default_logger);
 
    if (fd >= 0) {
        ast_cli(fd, "PJSIP Logging enabled\n");
    }
 
    return CLI_SUCCESS;
}
 
static char *pjsip_enable_logger_host(int fd, const char *arg, unsigned int add_host)
{
    const char *host = arg;
    char *mask;
    struct ast_sockaddr address;
    int error = 0;
 
    ao2_wrlock(default_logger);
    default_logger->enabled = 1;
 
    if (!add_host) {
        /* If this is not adding an additional host or subnet then we have to
         * remove what already exists.
         */
        ast_free_ha(default_logger->matches);
        default_logger->matches = NULL;
    }
 
    mask = strrchr(host, '/');
    if (!mask && !ast_sockaddr_parse(&address, arg, 0)) {
        if (ast_sockaddr_resolve_first_af(&address, arg, 0, AST_AF_UNSPEC)) {
            ao2_unlock(default_logger);
            return CLI_SHOWUSAGE;
        }
        host = ast_sockaddr_stringify(&address);
    }
 
    default_logger->matches = ast_append_ha_with_port("d", host, default_logger->matches, &error);
    if (!default_logger->matches || error) {
        if (fd >= 0) {
            ast_cli(fd, "Failed to add address '%s' for logging\n", host);
        }
        ao2_unlock(default_logger);
        return CLI_SUCCESS;
    }
 
    ao2_unlock(default_logger);
 
    if (fd >= 0) {
        ast_cli(fd, "PJSIP Logging Enabled for host: %s\n", ast_sockaddr_stringify_addr(&address));
    }
 
    return CLI_SUCCESS;
}
 
static struct method_logging_info *method_logging_info_alloc(const char *method)
{
    size_t method_bytes = strlen(method);
    struct method_logging_info *info;
 
    info = ast_calloc(1, sizeof(struct method_logging_info) + method_bytes + 1);
    if (!info) {
        return NULL;
    }
 
    memcpy(info->name, method, method_bytes + 1);
    pj_strset(&info->pj_name, info->name, method_bytes);
    pjsip_method_init_np(&info->method, &info->pj_name);
 
    return info;
}
 
static int method_logging_info_cmp(const struct method_logging_info *element,
    const struct method_logging_info *candidate)
{
    return pjsip_method_cmp(&element->method, &candidate->method) == 0
        ? CMP_MATCH | CMP_STOP
        : 0;
}
 
static int method_logging_info_sort_cmp(const void *a, const void *b)
{
    const struct method_logging_info *const *m_a = a;
    const struct method_logging_info *const *m_b = b;
    return strcasecmp((*m_a)->name, (*m_b)->name);
}
 
/*! \brief Add the current or an additional method to match for filtering */
static char *pjsip_enable_logger_method(int fd, const char *arg, int add_method)
{
    struct ast_str *str;
    struct method_logging_info *method;
 
    method = method_logging_info_alloc(arg);
    if (!method) {
        return CLI_FAILURE;
    }
 
    ao2_wrlock(default_logger);
    default_logger->enabled = 1;
 
    if (!add_method) {
        /* Remove what already exists */
        AST_VECTOR_RESET(&default_logger->log_methods, ast_free);
    }
 
    /* Already in the list? */
    if (AST_VECTOR_CALLBACK(&default_logger->log_methods, method_logging_info_cmp, NULL, method) != NULL) {
        ast_cli(fd, "Method '%s' is already enabled\n", method->name);
        ao2_unlock(default_logger);
        ast_free(method);
        return CLI_SUCCESS;
    }
 
    if (AST_VECTOR_APPEND(&default_logger->log_methods, method)) {
        ast_log(LOG_ERROR, "Cannot register logger method '%s'. Unable to append.\n", method->name);
        ao2_unlock(default_logger);
        ast_free(method);
        return CLI_SUCCESS;
    }
 
    AST_VECTOR_SORT(&default_logger->log_methods, method_logging_info_sort_cmp);
 
    str = ast_str_create(256);
    if (str) {
        size_t i;
        for (i = 0; i < AST_VECTOR_SIZE(&default_logger->log_methods); i++) {
            method = AST_VECTOR_GET(&default_logger->log_methods, i);
            ast_str_append(&str, 0, "%s%.*s",
                ast_str_strlen(str) ? ", " : "",
                (int) method->pj_name.slen, method->pj_name.ptr);
        }
 
        ast_cli(fd, "PJSIP Logging Enabled for SIP Methods: %s\n", ast_str_buffer(str));
        ast_free(str);
    }
 
    ao2_unlock(default_logger);
 
    return CLI_SUCCESS;
}
 
static char *pjsip_disable_logger(int fd)
{
    ao2_wrlock(default_logger);
 
    /* Default the settings back to the way they were */
    default_logger->enabled = 0;
    default_logger->log_all_traffic = 0;
    default_logger->pcap_filename[0] = '\0';
    default_logger->log_to_verbose = 1;
    default_logger->log_to_pcap = 0;
 
    AST_VECTOR_RESET(&default_logger->log_methods, ast_free);
 
    /* Stop logging to the PCAP file if active */
    if (default_logger->pcap_file) {
        fclose(default_logger->pcap_file);
        default_logger->pcap_file = NULL;
    }
 
    ast_free_ha(default_logger->matches);
    default_logger->matches = NULL;
 
    ao2_unlock(default_logger);
 
    if (fd >= 0) {
        ast_cli(fd, "PJSIP Logging disabled\n");
    }
 
    return CLI_SUCCESS;
}
 
static char *pjsip_set_logger_verbose(int fd, const char *arg)
{
    ao2_wrlock(default_logger);
    default_logger->log_to_verbose = ast_true(arg);
    ao2_unlock(default_logger);
 
    ast_cli(fd, "PJSIP Logging to verbose has been %s\n", ast_true(arg) ? "enabled" : "disabled");
 
    return CLI_SUCCESS;
}
 
static char *pjsip_set_logger_pcap(int fd, const char *arg)
{
    struct pcap_header pcap_header = {
        .magic_number = 0xa1b2c3d4,
        .version_major = 2,
        .version_minor = 4,
        .snaplen = 65535,
        .network = 1, /* We always use ethernet so we can combine IPv4 and IPv6 in same pcap */
    };
 
    ao2_wrlock(default_logger);
    ast_copy_string(default_logger->pcap_filename, arg, sizeof(default_logger->pcap_filename));
 
    if (default_logger->pcap_file) {
        fclose(default_logger->pcap_file);
        default_logger->pcap_file = NULL;
    }
 
    default_logger->pcap_file = fopen(arg, "wb");
    if (!default_logger->pcap_file) {
        ao2_unlock(default_logger);
        ast_cli(fd, "Failed to open file '%s' for pcap writing\n", arg);
        return CLI_SUCCESS;
    }
    fwrite(&pcap_header, 1, sizeof(struct pcap_header), default_logger->pcap_file);
 
    default_logger->log_to_pcap = 1;
    ao2_unlock(default_logger);
 
    ast_cli(fd, "PJSIP logging to pcap file '%s'\n", arg);
 
    return CLI_SUCCESS;
}
 
static char *pjsip_set_logger(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    static const char * const method_choices[] = {
        "INVITE", "CANCEL", "ACK",
        "BYE", "REGISTER", "OPTION",
        "SUBSCRIBE", "NOTIFY", "PUBLISH",
        "INFO", "MESSAGE",
        NULL
    };
 
    const char *what;
 
    if (cmd == CLI_INIT) {
        e->command = "pjsip set logger {on|off|host|add|method|methodadd|verbose|pcap}";
        e->usage =
            "Usage: pjsip set logger {on|off|host <name/subnet>|add <name/subnet>|method <method>|methodadd <method>|verbose <on/off>|pcap <filename>}\n"
            "       Enables or disabling logging of SIP packets\n"
            "       read on ports bound to PJSIP transports either\n"
            "       globally or enables logging for an individual\n"
            "       host or particular SIP method(s).\n"
            "       Messages can be filtered by SIP request methods\n"
            "       INVITE, CANCEL, ACK, BYE, REGISTER, OPTION\n"
            "       SUBSCRIBE, NOTIFY, PUBLISH, INFO, and MESSAGE\n";
        return NULL;
    } else if (cmd == CLI_GENERATE) {
        if (a->argc && !strncasecmp(a->argv[e->args - 1], "method", 6)) {
            return ast_cli_complete(a->word, method_choices, a->n);
        }
        return NULL;
    }
 
    what = a->argv[e->args - 1];     /* Guaranteed to exist */
 
    if (a->argc == e->args) {        /* on/off */
        if (!strcasecmp(what, "on")) {
            return pjsip_enable_logger_all(a->fd);
        } else if (!strcasecmp(what, "off")) {
            return pjsip_disable_logger(a->fd);
        }
    } else if (a->argc == e->args + 1) {
        if (!strcasecmp(what, "host")) {
            return pjsip_enable_logger_host(a->fd, a->argv[e->args], 0);
        } else if (!strcasecmp(what, "add")) {
            return pjsip_enable_logger_host(a->fd, a->argv[e->args], 1);
        } else if (!strcasecmp(what, "method")) {
            return pjsip_enable_logger_method(a->fd, a->argv[e->args], 0);
        } else if (!strcasecmp(what, "methodadd")) {
            return pjsip_enable_logger_method(a->fd, a->argv[e->args], 1);
        } else if (!strcasecmp(what, "verbose")) {
            return pjsip_set_logger_verbose(a->fd, a->argv[e->args]);
        } else if (!strcasecmp(what, "pcap")) {
            return pjsip_set_logger_pcap(a->fd, a->argv[e->args]);
        }
    }
 
    return CLI_SHOWUSAGE;
}
 
static struct ast_cli_entry cli_pjsip[] = {
    AST_CLI_DEFINE(pjsip_set_logger, "Enable/Disable PJSIP Logger Output")
};
 
static void check_debug(void)
{
    RAII_VAR(char *, debug, ast_sip_get_debug(), ast_free);
 
    if (ast_false(debug)) {
        pjsip_disable_logger(-1);
        return;
    }
 
    if (ast_true(debug)) {
        pjsip_enable_logger_all(-1);
        return;
    }
 
    if (pjsip_enable_logger_host(-1, debug, 0) != CLI_SUCCESS) {
        ast_log(LOG_WARNING, "Could not resolve host %s for debug "
            "logging\n", debug);
    }
}
 
static void global_reloaded(const char *object_type)
{
    check_debug();
}
 
static const struct ast_sorcery_observer global_observer = {
    .loaded = global_reloaded
};
 
static int load_module(void)
{
    if (ast_sorcery_observer_add(ast_sip_get_sorcery(), "global", &global_observer)) {
        ast_log(LOG_WARNING, "Unable to add global observer\n");
        return AST_MODULE_LOAD_DECLINE;
    }
 
    default_logger = pjsip_logger_session_alloc();
    if (!default_logger) {
        ast_sorcery_observer_remove(
            ast_sip_get_sorcery(), "global", &global_observer);
        ast_log(LOG_WARNING, "Unable to create default logger\n");
        return AST_MODULE_LOAD_DECLINE;
    }
 
    check_debug();
 
    ast_sip_register_service(&logging_module);
    ast_cli_register_multiple(cli_pjsip, ARRAY_LEN(cli_pjsip));
 
    return AST_MODULE_LOAD_SUCCESS;
}
 
static int unload_module(void)
{
    ast_cli_unregister_multiple(cli_pjsip, ARRAY_LEN(cli_pjsip));
    ast_sip_unregister_service(&logging_module);
 
    ast_sorcery_observer_remove(
        ast_sip_get_sorcery(), "global", &global_observer);
 
    ao2_cleanup(default_logger);
    default_logger = NULL;
 
    return 0;
}
 
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP Packet Logger",
    .support_level = AST_MODULE_SUPPORT_CORE,
    .load = load_module,
    .unload = unload_module,
    .load_pri = AST_MODPRI_APP_DEPEND,
    .requires = "res_pjsip",
);