1#include "detection/dns/dns.h"
  2
  3#include "common/io.h"
  4#include "common/mallocHelper.h"
  5#include "common/strutil.h"
  6#include "common/debug.h"
  7
  8#ifdef __HAIKU__
  9    #define RESOLV_CONF "/system/settings/network/resolv.conf"
 10#else
 11    #define RESOLV_CONF "/etc/resolv.conf"
 12#endif
 13
 14static const char* detectDnsFromConf(const char* path, FFDNSOptions* options, FFlist* results) {
 15    FF_DEBUG("Attempting to read DNS config from %s", path);
 16
 17    FF_AUTO_CLOSE_FILE FILE* file = fopen(path, "r");
 18    if (!file) {
 19        FF_DEBUG("Failed to open %s: %s", path, strerror(errno));
 20        return "fopen(path, r) failed";
 21    }
 22
 23    if (results->length > 0) {
 24        FF_DEBUG("Clearing existing DNS entries (%u entries)", results->length);
 25        FF_LIST_FOR_EACH (FFstrbuf, item, *results) {
 26            ffStrbufDestroy(item);
 27        }
 28        ffListClear(results);
 29    }
 30
 31    FF_AUTO_FREE char* line = nullptr;
 32    size_t len = 0;
 33
 34    while (getline(&line, &len, file) != -1) {
 35        if (ffStrStartsWith(line, "nameserver")) {
 36            char* nameserver = line + strlen("nameserver");
 37            while (*nameserver == ' ' || *nameserver == '\t') {
 38                nameserver++;
 39            }
 40            if (*nameserver == '\0') {
 41                continue;
 42            }
 43
 44            char* comment = strchr(nameserver, '#');
 45            if (comment) {
 46                *comment = '\0';
 47            }
 48
 49            if ((ffStrContainsC(nameserver, ':') && !(options->showType & FF_DNS_TYPE_IPV6_BIT)) ||
 50                (ffStrContainsC(nameserver, '.') && !(options->showType & FF_DNS_TYPE_IPV4_BIT))) {
 51                continue;
 52            }
 53
 54            FFstrbuf* item = FF_LIST_ADD(FFstrbuf, *results);
 55            ffStrbufInitS(item, nameserver);
 56            ffStrbufTrimRightSpace(item);
 57            FF_DEBUG("Found DNS server: %s", item->chars);
 58        }
 59    }
 60
 61    FF_DEBUG("Found %u DNS servers in %s", results->length, path);
 62    return nullptr;
 63}
 64
 65const char* ffDetectDNS(FFDNSOptions* options, FFlist* results) {
 66    FF_DEBUG("Starting DNS detection");
 67
 68    const char* error = detectDnsFromConf(FASTFETCH_TARGET_DIR_ROOT RESOLV_CONF, options, results);
 69    if (error != nullptr) {
 70        FF_DEBUG("Error detecting DNS: %s", error);
 71        return error;
 72    }
 73
 74#if __linux__ && !__ANDROID__
 75    // Handle different DNS management services
 76    if (results->length == 1) {
 77        const FFstrbuf* firstEntry = FF_LIST_FIRST(FFstrbuf, *results);
 78
 79        if (ffStrbufEqualS(firstEntry, "127.0.0.53")) {
 80            FF_DEBUG("Detected systemd-resolved (127.0.0.53), checking actual DNS servers");
 81            // Managed by systemd-resolved
 82            if (detectDnsFromConf("/run/systemd/resolve/resolv.conf", options, results) == nullptr) {
 83                return nullptr;
 84            }
 85        } else if (ffStrbufEqualS(firstEntry, "127.0.0.1")) {
 86            FF_DEBUG("Detected possible NetworkManager (127.0.0.1), checking actual DNS servers");
 87            // Managed by NetworkManager
 88            if (detectDnsFromConf("/var/run/NetworkManager/resolv.conf", options, results) == nullptr) {
 89                return nullptr;
 90            }
 91        }
 92    }
 93
 94    // Check other possible DNS configuration files
 95    if (results->length == 0) {
 96        FF_DEBUG("No DNS servers found, trying alternative config files");
 97
 98        // Try resolvconf
 99        FF_DEBUG("Trying resolvconf configuration");
100        if (detectDnsFromConf(FASTFETCH_TARGET_DIR_ROOT "/run/resolvconf/resolv.conf", options, results) == nullptr && results->length > 0) {
101            return nullptr;
102        }
103
104        // Try dnsmasq
105        FF_DEBUG("Trying dnsmasq configuration");
106        if (detectDnsFromConf(FASTFETCH_TARGET_DIR_ROOT "/var/run/dnsmasq/resolv.conf", options, results) == nullptr && results->length > 0) {
107            return nullptr;
108        }
109
110        // Try openresolv
111        FF_DEBUG("Trying openresolv configuration");
112        if (detectDnsFromConf(FASTFETCH_TARGET_DIR_ROOT "/etc/resolv.conf.openresolv", options, results) == nullptr && results->length > 0) {
113            return nullptr;
114        }
115    }
116#elif defined(__FreeBSD__) || defined(__DragonFly__) || defined(__NetBSD__) || defined(__OpenBSD__)
117    // Handle BSD-specific DNS configurations
118    if (results->length == 0) {
119        FF_DEBUG("No DNS servers found, trying BSD-specific config files");
120
121        // FreeBSD and other BSDs may use resolvconf service
122        FF_DEBUG("Trying BSD resolvconf configuration");
123        if (detectDnsFromConf(FASTFETCH_TARGET_DIR_ROOT "/var/run/resolvconf/resolv.conf", options, results) == nullptr && results->length > 0) {
124            return nullptr;
125        }
126
127        // Some BSDs store DNS configuration here
128        FF_DEBUG("Trying BSD nameserver configuration");
129        if (detectDnsFromConf(FASTFETCH_TARGET_DIR_ROOT "/var/run/nameserver", options, results) == nullptr && results->length > 0) {
130            return nullptr;
131        }
132
133        // Try common BSD paths
134        FF_DEBUG("Trying BSD common paths");
135        if (detectDnsFromConf(FASTFETCH_TARGET_DIR_ROOT "/etc/nameserver", options, results) == nullptr && results->length > 0) {
136            return nullptr;
137        }
138    }
139#endif
140
141    FF_DEBUG("DNS detection completed with %u servers found", results->length);
142    return nullptr;
143}