ip2name.c

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/*
 * SARG Squid Analysis Report Generator      http://sarg.sourceforge.net
 *                                                            1998, 2015
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 *
 *  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, USA.
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 */
 
#include "include/conf.h"
#include "include/defs.h"
#include "include/ip2name.h"
#include "include/dichotomic.h"
 
struct Ip2NameModules
{
    const char *Name;
    struct Ip2NameProcess *Process;
};
 
extern struct Ip2NameProcess Ip2NameDns;
extern struct Ip2NameProcess Ip2NameExec;
 
static const struct Ip2NameModules ModulesList[]=
{
    {"dns",&Ip2NameDns},
    {"exec",&Ip2NameExec},
    {"yes",&Ip2NameDns},//for historical compatibility
    {"no",NULL},//does nothing for compatibility with previous versions
};
 
static struct Ip2NameProcess *FirstModule=NULL;
static DichotomicObject KnownIp=NULL;
 
static void ip2name_chainmodule(struct Ip2NameProcess *Module)
{
    struct Ip2NameProcess *Chain;
    struct Ip2NameProcess *Last;
 
    if (debug) debuga(__FILE__,__LINE__,_("Chaining IP resolving module \"%s\"\n"),Module->Name);
 
    Last=NULL;
    for (Chain=FirstModule ; Chain ; Chain=Chain->Next) {
        if (Chain==Module) {
            debuga(__FILE__,__LINE__,_("Ignoring duplicate module \"%s\" to resolve an IP address\n"),Module->Name);
            return;
        }
        Last=Chain;
    }
 
    if (Last)
        Last->Next=Module;
    else {
        FirstModule=Module;
        Ip2Name=true;
    }
}
 
static void ip2name_buildmoduleslist(const char *list)
{
    const char *candidate;
    int length;
    int ModuleIdx;
 
    while (*list) {
        candidate=list;
        while (*candidate && (unsigned char)*candidate<=' ') candidate++;
        for (length=0 ; (unsigned char)candidate[length]>' ' ; length++);
        for (ModuleIdx=0 ; ModuleIdx<sizeof(ModulesList)/sizeof(*ModulesList) ; ModuleIdx++) {
            if (strncasecmp(candidate,ModulesList[ModuleIdx].Name,length)==0 && ModulesList[ModuleIdx].Name[length]=='\0') {
                // module found
                if (ModulesList[ModuleIdx].Process)
                    ip2name_chainmodule(ModulesList[ModuleIdx].Process);
                break;
            }
        }
        if (ModuleIdx>=sizeof(ModulesList)/sizeof(*ModulesList)) {
            debuga(__FILE__,__LINE__,_("Unknown module \"%.*s\" to resolve the IP addresses\n"),length,candidate);
            exit(EXIT_FAILURE);
        }
        list=candidate+length;
    }
}
 
static void ip2name_configmodule(const char *module)
{
    int length;
    unsigned int ModuleIdx;
 
    for (length=0 ; module[length] && (unsigned char)module[length]>' ' ; length++);
    for (ModuleIdx=0 ; ModuleIdx<sizeof(ModulesList)/sizeof(*ModulesList) ; ModuleIdx++) {
        if (strncasecmp(module,ModulesList[ModuleIdx].Name,length)==0 && ModulesList[ModuleIdx].Name[length]=='\0') {
            // module found
            if (ModulesList[ModuleIdx].Process) {
                if (!ModulesList[ModuleIdx].Process->Configure) {
                    debuga(__FILE__,__LINE__,_("No option to configure for module %s\n"),ModulesList[ModuleIdx].Name);
                    exit(EXIT_FAILURE);
                }
                while (module[length] && (unsigned char)module[length]<=' ') length++;
                ModulesList[ModuleIdx].Process->Configure(ModulesList[ModuleIdx].Name,module+length);
            }
            break;
        }
    }
}
 
int ip2name_config(const char *param)
{
    // module to add to the list
    if (*param==' ') {
        ip2name_buildmoduleslist(param);
        return(1);
    }
 
    // parameter for a module?
    if (*param=='_') {
        ip2name_configmodule(param+1);
        return(1);
    }
 
    return(0);
}
 
void ip2name_forcedns(void)
{
    struct Ip2NameProcess *DnsModule=NULL;
    int i;
    struct Ip2NameProcess *Chain;
    struct Ip2NameProcess *Last;
 
    // find the dns module
    for (i=0 ; i<sizeof(ModulesList)/sizeof(*ModulesList) ; i++) {
        if (strcmp("dns",ModulesList[i].Name)==0) {
            // module found
            DnsModule=ModulesList[i].Process;
            break;
        }
    }
    if (!DnsModule) {
        debuga(__FILE__,__LINE__,_("No known module to resolve an IP address using the DNS\n"));
        exit(EXIT_FAILURE);
    }
 
    // add the module to the list if it isn't there yet
    Last=NULL;
    for (Chain=FirstModule ; Chain && Chain!=DnsModule ; Chain=Chain->Next) {
        Last=Chain;
    }
    if (debug) debuga(__FILE__,__LINE__,_("Chaining IP resolving module \"%s\"\n"),DnsModule->Name);
    if (Last)
        Last->Next=DnsModule;
    else {
        FirstModule=DnsModule;
        Ip2Name=true;
    }
}
 
void ip2name(char *ip,int ip_len)
{
    struct Ip2NameProcess *Module;
    enum ip2name_retcode Status;
    const char *Name;
    char OrigIp[80];
 
    if (!KnownIp) {
        KnownIp=Dichotomic_Create();
        if (!KnownIp) {
            debuga(__FILE__,__LINE__,_("Not enough memory to store the names corresponding to the IP address\n"));
            exit(EXIT_FAILURE);
        }
    }
 
    Name=Dichotomic_Search(KnownIp,ip);
    if (Name) {
        safe_strcpy(ip,Name,ip_len);
        return;
    }
 
    safe_strcpy(OrigIp,ip,sizeof(OrigIp));
    for (Module=FirstModule ; Module ; Module=Module->Next) {
        if (Module->Resolve) {
            Status=Module->Resolve(ip,ip_len);
            if (Status==INRC_Found) break;
        }
    }
    Dichotomic_Insert(KnownIp,OrigIp,ip);
}
 
void ip2name_cleanup(void)
{
    Dichotomic_Destroy(&KnownIp);
}
 
void name2ip(char *name,int name_size)
{
#ifdef HAVE_GETADDRINFO
    int error;
    char *port;
    struct addrinfo *res=NULL;
    char *addr;
 
    addr=name;
    if (name[0]=='[') { //IPv6 address
        port=strchr(name,']');
        if (port) { //confirmed IPv6 address
            *port='\0';
            addr++;
        }
    } else { //IPv4 address
        port=strchr(name,':');
        if (port) *port='\0';
    }
 
    error=getaddrinfo(addr,NULL,NULL,&res);
    if (error) {
        if (res) freeaddrinfo(res);
        debuga(__FILE__,__LINE__,_("Cannot resolve host name \"%s\": %s\n"),name,gai_strerror(error));
    } else {
        if (res->ai_family==AF_INET) {
            struct sockaddr_in *s4=(struct sockaddr_in *)res->ai_addr;
            struct in_addr *sa=&s4->sin_addr;
            if (res->ai_addrlen<sizeof(*s4)) {
                debuga(__FILE__,__LINE__,_("Short structure returned by getaddrinfo for an IPv4 address: %d bytes instead of %d\n"),res->ai_addrlen,(int)sizeof(*s4));
                exit(EXIT_FAILURE);
            }
            inet_ntop(res->ai_family,sa,name,name_size);
        } else if (res->ai_family==AF_INET6) {
            struct sockaddr_in6 *s6=(struct sockaddr_in6 *)res->ai_addr;
            struct in6_addr *sa6=&s6->sin6_addr;
            if (res->ai_addrlen<sizeof(*s6)) {
                debuga(__FILE__,__LINE__,_("Short structure returned by getaddrinfo for an IPv6 address: %d bytes instead of %d\n"),res->ai_addrlen,(int)sizeof(*s6));
                exit(EXIT_FAILURE);
            }
            inet_ntop(res->ai_family,sa6,name,name_size);
        } else {
            debuga(__FILE__,__LINE__,_("Invalid address type %d returned when resolving host name \"%s\"\n"),res->ai_family,name);
        }
        freeaddrinfo(res);
    }
#else
    struct in_addr ia;
    struct hostent *hp;
    char *port;
    char n1[4];
    char n2[4];
    char n3[4];
    char n4[4];
    struct getwordstruct gwarea;
 
    port=strchr(name,':');
    if (port) *port='\0';
 
    if ((hp=gethostbyname(name))==NULL)
        return;
 
    memcpy(&ia.s_addr,hp->h_addr_list[0],sizeof(ia.s_addr));
    ia.s_addr=ntohl(ia.s_addr);
    getword_start(&gwarea,inet_ntoa(ia));
    if (getword(n4,sizeof(n4),&gwarea,'.')<0 || getword(n3,sizeof(n3),&gwarea,'.')<0 ||
        getword(n2,sizeof(n2),&gwarea,'.')<0 || getword(n1,sizeof(n1),&gwarea,0)<0) {
        debuga(__FILE__,__LINE__,_("Invalid IPv4 address \"%s\"\n"),gwarea.beginning);
        exit(EXIT_FAILURE);
    }
    snprintf(name,name_size,"%s.%s.%s.%s",n1,n2,n3,n4);
#endif
 
    return;
}