X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=dns.c;h=e485ed8467b464183871c2ab7808b5902f256e69;hb=7dce450bdc23ea306a61e00f914481e29ebcb176;hp=243c5a33c1703f2973664b92ac32fdba2a6fd275;hpb=4aa744ffac20c7b5e18cb3b23e5dbac8221c0043;p=catta diff --git a/dns.c b/dns.c index 243c5a3..e485ed8 100644 --- a/dns.c +++ b/dns.c @@ -1,123 +1,188 @@ +#include + #include #include #include #include "dns.h" +#include "util.h" -flxDnsPacket* flx_dns_packet_new(guint max_size) { - flxDnsPacket *p; +AvahiDnsPacket* avahi_dns_packet_new(guint max_size) { + AvahiDnsPacket *p; if (max_size <= 0) - max_size = FLX_DNS_PACKET_MAX_SIZE; - else if (max_size < FLX_DNS_PACKET_HEADER_SIZE) - max_size = FLX_DNS_PACKET_HEADER_SIZE; + max_size = AVAHI_DNS_PACKET_MAX_SIZE; + else if (max_size < AVAHI_DNS_PACKET_HEADER_SIZE) + max_size = AVAHI_DNS_PACKET_HEADER_SIZE; - p = g_malloc(sizeof(flxDnsPacket) + max_size); - p->size = p->rindex = FLX_DNS_PACKET_HEADER_SIZE; + p = g_malloc(sizeof(AvahiDnsPacket) + max_size); + p->size = p->rindex = AVAHI_DNS_PACKET_HEADER_SIZE; p->max_size = max_size; + p->name_table = NULL; - memset(FLX_DNS_PACKET_DATA(p), 0, p->size); + memset(AVAHI_DNS_PACKET_DATA(p), 0, p->size); return p; } -flxDnsPacket* flx_dns_packet_new_query(guint max_size) { - flxDnsPacket *p; +AvahiDnsPacket* avahi_dns_packet_new_query(guint max_size) { + AvahiDnsPacket *p; - p = flx_dns_packet_new(max_size); - flx_dns_packet_set_field(p, DNS_FIELD_FLAGS, DNS_FLAGS(0, 0, 0, 0, 0, 0, 0, 0, 0, 0)); + p = avahi_dns_packet_new(max_size); + avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_FLAGS, AVAHI_DNS_FLAGS(0, 0, 0, 0, 0, 0, 0, 0, 0, 0)); return p; } -flxDnsPacket* flx_dns_packet_new_response(guint max_size) { - flxDnsPacket *p; +AvahiDnsPacket* avahi_dns_packet_new_response(guint max_size) { + AvahiDnsPacket *p; - p = flx_dns_packet_new(max_size); - flx_dns_packet_set_field(p, DNS_FIELD_FLAGS, DNS_FLAGS(1, 0, 0, 0, 0, 0, 0, 0, 0, 0)); + p = avahi_dns_packet_new(max_size); + avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_FLAGS, AVAHI_DNS_FLAGS(1, 0, 0, 0, 0, 0, 0, 0, 0, 0)); return p; } -void flx_dns_packet_free(flxDnsPacket *p) { +void avahi_dns_packet_free(AvahiDnsPacket *p) { g_assert(p); + + if (p->name_table) + g_hash_table_destroy(p->name_table); + g_free(p); } -void flx_dns_packet_set_field(flxDnsPacket *p, guint index, guint16 v) { +void avahi_dns_packet_set_field(AvahiDnsPacket *p, guint index, guint16 v) { g_assert(p); - g_assert(index < FLX_DNS_PACKET_HEADER_SIZE); + g_assert(index < AVAHI_DNS_PACKET_HEADER_SIZE); - ((guint16*) FLX_DNS_PACKET_DATA(p))[index] = g_htons(v); + ((guint16*) AVAHI_DNS_PACKET_DATA(p))[index] = g_htons(v); } -guint16 flx_dns_packet_get_field(flxDnsPacket *p, guint index) { +guint16 avahi_dns_packet_get_field(AvahiDnsPacket *p, guint index) { g_assert(p); - g_assert(index < FLX_DNS_PACKET_HEADER_SIZE); + g_assert(index < AVAHI_DNS_PACKET_HEADER_SIZE); + + return g_ntohs(((guint16*) AVAHI_DNS_PACKET_DATA(p))[index]); +} + +/* Read the first label from string *name, unescape "\" and write it to dest */ +gchar *avahi_unescape_label(gchar *dest, guint size, const gchar **name) { + guint i = 0; + gchar *d; + + g_assert(dest); + g_assert(size > 0); + g_assert(name); + g_assert(*name); + + d = dest; + + for (;;) { + if (i >= size) + return NULL; + + if (**name == '.') { + (*name)++; + break; + } + + if (**name == 0) + break; + + if (**name == '\\') { + (*name) ++; + + if (**name == 0) + break; + } + + *(d++) = *((*name) ++); + i++; + } - return g_ntohs(((guint16*) FLX_DNS_PACKET_DATA(p))[index]); + g_assert(i < size); + + *d = 0; + + return dest; } -guint8* flx_dns_packet_append_name(flxDnsPacket *p, const gchar *name) { - guint8 *d, *f = NULL; +guint8* avahi_dns_packet_append_name(AvahiDnsPacket *p, const gchar *name) { + guint8 *d, *saved_ptr = NULL; guint saved_size; g_assert(p); g_assert(name); saved_size = p->size; + saved_ptr = avahi_dns_packet_extend(p, 0); + + while (*name) { + guint n; + guint8* prev; + const gchar *pname; + gchar label[64]; - for (;;) { - guint n = strcspn(name, "."); - if (!n || n > 63) - goto fail; - - if (!(d = flx_dns_packet_extend(p, n+1))) - goto fail; + /* Check whether we can compress this name. */ + + if (p->name_table && (prev = g_hash_table_lookup(p->name_table, name))) { + guint index; - if (!f) - f = d; - d[0] = n; - memcpy(d+1, name, n); + g_assert(prev >= AVAHI_DNS_PACKET_DATA(p)); + index = (guint) (prev - AVAHI_DNS_PACKET_DATA(p)); - name += n; + g_assert(index < p->size); - /* no trailing dot */ - if (!*name) - break; + if (index < 0x4000) { + guint16 *t; + if (!(t = (guint16*) avahi_dns_packet_extend(p, sizeof(guint16)))) + return NULL; - name ++; + *t = g_htons((0xC000 | index)); + return saved_ptr; + } + } - /* trailing dot */ - if (!*name) - break; + pname = name; + + if (!(avahi_unescape_label(label, sizeof(label), &name))) + goto fail; + + if (!(d = avahi_dns_packet_append_string(p, label))) + goto fail; + + if (!p->name_table) + p->name_table = g_hash_table_new_full((GHashFunc) avahi_domain_hash, (GEqualFunc) avahi_domain_equal, g_free, NULL); + + g_hash_table_insert(p->name_table, g_strdup(pname), d); } - if (!(d = flx_dns_packet_extend(p, 1))) + if (!(d = avahi_dns_packet_extend(p, 1))) goto fail; - d[0] = 0; + *d = 0; - return f; + return saved_ptr; fail: p->size = saved_size; return NULL; } -guint8* flx_dns_packet_append_uint16(flxDnsPacket *p, guint16 v) { +guint8* avahi_dns_packet_append_uint16(AvahiDnsPacket *p, guint16 v) { guint8 *d; g_assert(p); - if (!(d = flx_dns_packet_extend(p, sizeof(guint16)))) + if (!(d = avahi_dns_packet_extend(p, sizeof(guint16)))) return NULL; *((guint16*) d) = g_htons(v); return d; } -guint8 *flx_dns_packet_append_uint32(flxDnsPacket *p, guint32 v) { +guint8 *avahi_dns_packet_append_uint32(AvahiDnsPacket *p, guint32 v) { guint8 *d; g_assert(p); - if (!(d = flx_dns_packet_extend(p, sizeof(guint32)))) + if (!(d = avahi_dns_packet_extend(p, sizeof(guint32)))) return NULL; *((guint32*) d) = g_htonl(v); @@ -125,75 +190,111 @@ guint8 *flx_dns_packet_append_uint32(flxDnsPacket *p, guint32 v) { return d; } -guint8 *flx_dns_packet_append_bytes(flxDnsPacket *p, gconstpointer b, guint l) { +guint8 *avahi_dns_packet_append_bytes(AvahiDnsPacket *p, gconstpointer b, guint l) { guint8* d; g_assert(p); g_assert(b); g_assert(l); - if (!(d = flx_dns_packet_extend(p, l))) + if (!(d = avahi_dns_packet_extend(p, l))) return NULL; memcpy(d, b, l); return d; } -guint8 *flx_dns_packet_extend(flxDnsPacket *p, guint l) { - guint8 *d; +guint8* avahi_dns_packet_append_string(AvahiDnsPacket *p, const gchar *s) { + guint8* d; + guint k; g_assert(p); + g_assert(s); - if (p->size+l > p->max_size) - return NULL; - - d = FLX_DNS_PACKET_DATA(p) + p->size; - p->size += l; + if ((k = strlen(s)) >= 255) + k = 255; + if (!(d = avahi_dns_packet_extend(p, k+1))) + return NULL; + + *d = (guint8) k; + memcpy(d+1, s, k); + return d; } -guint8 *flx_dns_packet_append_name_compressed(flxDnsPacket *p, const gchar *name, guint8 *prev) { - guint16 *d; - signed long k; - g_assert(p); - - if (!prev) - return flx_dns_packet_append_name(p, name); +guint8 *avahi_dns_packet_extend(AvahiDnsPacket *p, guint l) { + guint8 *d; - k = prev - FLX_DNS_PACKET_DATA(p); - if (k < 0 || k >= 0x4000 || (guint) k >= p->size) - return flx_dns_packet_append_name(p, name); + g_assert(p); - if (!(d = (guint16*) flx_dns_packet_extend(p, sizeof(guint16)))) + if (p->size+l > p->max_size) return NULL; - *d = g_htons((0xC000 | k)); - return prev; + d = AVAHI_DNS_PACKET_DATA(p) + p->size; + p->size += l; + + return d; } -gint flx_dns_packet_check_valid(flxDnsPacket *p) { +gint avahi_dns_packet_check_valid(AvahiDnsPacket *p) { guint16 flags; g_assert(p); if (p->size < 12) return -1; - flags = flx_dns_packet_get_field(p, DNS_FIELD_FLAGS); + flags = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS); - if (flags & DNS_FLAG_OPCODE || flags & DNS_FLAG_RCODE) + if (flags & AVAHI_DNS_FLAG_OPCODE || flags & AVAHI_DNS_FLAG_RCODE) return -1; return 0; } -gint flx_dns_packet_is_query(flxDnsPacket *p) { +gint avahi_dns_packet_is_query(AvahiDnsPacket *p) { g_assert(p); - return !(flx_dns_packet_get_field(p, DNS_FIELD_FLAGS) & DNS_FLAG_QR); + return !(avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS) & AVAHI_DNS_FLAG_QR); +} + +/* Read a label from a DNS packet, escape "\" and ".", append \0 */ +static gchar *escape_label(guint8* src, guint src_length, gchar **ret_name, guint *ret_name_length) { + gchar *r; + + g_assert(src); + g_assert(ret_name); + g_assert(*ret_name); + g_assert(ret_name_length); + g_assert(*ret_name_length > 0); + + r = *ret_name; + + while (src_length > 0) { + if (*src == '.' || *src == '\\') { + if (*ret_name_length < 3) + return NULL; + + *((*ret_name) ++) = '\\'; + (*ret_name_length) --; + } + + if (*ret_name_length < 2) + return NULL; + + *((*ret_name)++) = *src; + (*ret_name_length) --; + + src_length --; + src++; + } + + **ret_name = 0; + + return r; } -static gint consume_labels(flxDnsPacket *p, guint index, gchar *ret_name, guint l) { +static gint consume_labels(AvahiDnsPacket *p, guint index, gchar *ret_name, guint l) { gint ret = 0; int compressed = 0; int first_label = 1; @@ -205,7 +306,7 @@ static gint consume_labels(flxDnsPacket *p, guint index, gchar *ret_name, guint if (index+1 > p->size) return -1; - n = FLX_DNS_PACKET_DATA(p)[index]; + n = AVAHI_DNS_PACKET_DATA(p)[index]; if (!n) { index++; @@ -236,10 +337,10 @@ static gint consume_labels(flxDnsPacket *p, guint index, gchar *ret_name, guint } else first_label = 0; - memcpy(ret_name, FLX_DNS_PACKET_DATA(p) + index, n); + if (!(escape_label(AVAHI_DNS_PACKET_DATA(p) + index, n, &ret_name, &l))) + return -1; + index += n; - ret_name += n; - l -= n; if (!compressed) ret += n; @@ -249,7 +350,7 @@ static gint consume_labels(flxDnsPacket *p, guint index, gchar *ret_name, guint if (index+2 > p->size) return -1; - index = ((guint) (FLX_DNS_PACKET_DATA(p)[index] & ~0xC0)) << 8 | FLX_DNS_PACKET_DATA(p)[index+1]; + index = ((guint) (AVAHI_DNS_PACKET_DATA(p)[index] & ~0xC0)) << 8 | AVAHI_DNS_PACKET_DATA(p)[index+1]; if (!compressed) ret += 2; @@ -260,7 +361,7 @@ static gint consume_labels(flxDnsPacket *p, guint index, gchar *ret_name, guint } } -gint flx_dns_packet_consume_name(flxDnsPacket *p, gchar *ret_name, guint l) { +gint avahi_dns_packet_consume_name(AvahiDnsPacket *p, gchar *ret_name, guint l) { gint r; if ((r = consume_labels(p, p->rindex, ret_name, l)) < 0) @@ -270,33 +371,33 @@ gint flx_dns_packet_consume_name(flxDnsPacket *p, gchar *ret_name, guint l) { return 0; } -gint flx_dns_packet_consume_uint16(flxDnsPacket *p, guint16 *ret_v) { +gint avahi_dns_packet_consume_uint16(AvahiDnsPacket *p, guint16 *ret_v) { g_assert(p); g_assert(ret_v); if (p->rindex + sizeof(guint16) > p->size) return -1; - *ret_v = g_ntohs(*((guint16*) (FLX_DNS_PACKET_DATA(p) + p->rindex))); + *ret_v = g_ntohs(*((guint16*) (AVAHI_DNS_PACKET_DATA(p) + p->rindex))); p->rindex += sizeof(guint16); return 0; } -gint flx_dns_packet_consume_uint32(flxDnsPacket *p, guint32 *ret_v) { +gint avahi_dns_packet_consume_uint32(AvahiDnsPacket *p, guint32 *ret_v) { g_assert(p); g_assert(ret_v); if (p->rindex + sizeof(guint32) > p->size) return -1; - *ret_v = g_ntohl(*((guint32*) (FLX_DNS_PACKET_DATA(p) + p->rindex))); + *ret_v = g_ntohl(*((guint32*) (AVAHI_DNS_PACKET_DATA(p) + p->rindex))); p->rindex += sizeof(guint32); return 0; } -gint flx_dns_packet_consume_bytes(flxDnsPacket *p, gpointer ret_data, guint l) { +gint avahi_dns_packet_consume_bytes(AvahiDnsPacket *p, gpointer ret_data, guint l) { g_assert(p); g_assert(ret_data); g_assert(l > 0); @@ -304,22 +405,50 @@ gint flx_dns_packet_consume_bytes(flxDnsPacket *p, gpointer ret_data, guint l) { if (p->rindex + l > p->size) return -1; - memcpy(ret_data, FLX_DNS_PACKET_DATA(p) + p->rindex, l); + memcpy(ret_data, AVAHI_DNS_PACKET_DATA(p) + p->rindex, l); p->rindex += l; return 0; } -gconstpointer flx_dns_packet_get_rptr(flxDnsPacket *p) { - g_assert(p); +gint avahi_dns_packet_consume_string(AvahiDnsPacket *p, gchar *ret_string, guint l) { + guint k; + g_assert(p); + g_assert(ret_string); + g_assert(l > 0); + if (p->rindex >= p->size) + return -1; + + k = AVAHI_DNS_PACKET_DATA(p)[p->rindex]; + + if (p->rindex+1+k > p->size) + return -1; + + if (l > k+1) + l = k+1; + + memcpy(ret_string, AVAHI_DNS_PACKET_DATA(p)+p->rindex+1, l-1); + ret_string[l-1] = 0; + + + p->rindex += 1+k; + + return 0; + +} + +gconstpointer avahi_dns_packet_get_rptr(AvahiDnsPacket *p) { + g_assert(p); + + if (p->rindex > p->size) return NULL; - return FLX_DNS_PACKET_DATA(p) + p->rindex; + return AVAHI_DNS_PACKET_DATA(p) + p->rindex; } -gint flx_dns_packet_skip(flxDnsPacket *p, guint length) { +gint avahi_dns_packet_skip(AvahiDnsPacket *p, guint length) { g_assert(p); if (p->rindex + length > p->size) @@ -329,147 +458,292 @@ gint flx_dns_packet_skip(flxDnsPacket *p, guint length) { return 0; } -flxRecord* flx_dns_packet_consume_record(flxDnsPacket *p, gboolean *ret_cache_flush) { - gchar name[257], buf[257+6]; +AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, gboolean *ret_cache_flush) { + gchar name[257], buf[257]; guint16 type, class; guint32 ttl; guint16 rdlength; gconstpointer data; + AvahiRecord *r = NULL; + gconstpointer start; g_assert(p); g_assert(ret_cache_flush); - if (flx_dns_packet_consume_name(p, name, sizeof(name)) < 0 || - flx_dns_packet_consume_uint16(p, &type) < 0 || - flx_dns_packet_consume_uint16(p, &class) < 0 || - flx_dns_packet_consume_uint32(p, &ttl) < 0 || - flx_dns_packet_consume_uint16(p, &rdlength) < 0) - return NULL; +/* g_message("consume_record()"); */ + + if (avahi_dns_packet_consume_name(p, name, sizeof(name)) < 0 || + avahi_dns_packet_consume_uint16(p, &type) < 0 || + avahi_dns_packet_consume_uint16(p, &class) < 0 || + avahi_dns_packet_consume_uint32(p, &ttl) < 0 || + avahi_dns_packet_consume_uint16(p, &rdlength) < 0 || + p->rindex + rdlength > p->size) + goto fail; +/* g_message("name = %s, rdlength = %u", name, rdlength); */ + + *ret_cache_flush = !!(class & AVAHI_DNS_CACHE_FLUSH); + class &= ~AVAHI_DNS_CACHE_FLUSH; + + start = avahi_dns_packet_get_rptr(p); + + r = avahi_record_new_full(name, class, type); + switch (type) { - case FLX_DNS_TYPE_PTR: - case FLX_DNS_TYPE_CNAME: - if (flx_dns_packet_consume_name(p, buf, sizeof(buf)) < 0) - return NULL; + case AVAHI_DNS_TYPE_PTR: + case AVAHI_DNS_TYPE_CNAME: + +/* g_message("ptr"); */ - data = buf; - rdlength = strlen(buf); + if (avahi_dns_packet_consume_name(p, buf, sizeof(buf)) < 0) + goto fail; + + r->data.ptr.name = g_strdup(buf); break; - case FLX_DNS_TYPE_SRV: { - const guint8 *t = flx_dns_packet_get_rptr(p); + + case AVAHI_DNS_TYPE_SRV: - if (flx_dns_packet_skip(p, 6) < 0) - return NULL; +/* g_message("srv"); */ - memcpy(buf, t, 6); + if (avahi_dns_packet_consume_uint16(p, &r->data.srv.priority) < 0 || + avahi_dns_packet_consume_uint16(p, &r->data.srv.weight) < 0 || + avahi_dns_packet_consume_uint16(p, &r->data.srv.port) < 0 || + avahi_dns_packet_consume_name(p, buf, sizeof(buf)) < 0) + goto fail; + + r->data.srv.name = g_strdup(buf); + break; - if (flx_dns_packet_consume_name(p, buf+6, sizeof(buf)-6) < 0) - return NULL; + case AVAHI_DNS_TYPE_HINFO: + +/* g_message("hinfo"); */ + + if (avahi_dns_packet_consume_string(p, buf, sizeof(buf)) < 0) + goto fail; + + r->data.hinfo.cpu = g_strdup(buf); - data = buf; - rdlength = 6 + strlen(buf+6); + if (avahi_dns_packet_consume_string(p, buf, sizeof(buf)) < 0) + goto fail; + + r->data.hinfo.os = g_strdup(buf); + break; + + case AVAHI_DNS_TYPE_TXT: + +/* g_message("txt"); */ + + if (rdlength > 0) { + r->data.txt.string_list = avahi_string_list_parse(avahi_dns_packet_get_rptr(p), rdlength); + + if (avahi_dns_packet_skip(p, rdlength) < 0) + goto fail; + } else + r->data.txt.string_list = NULL; + + break; + + case AVAHI_DNS_TYPE_A: + +/* g_message("A"); */ + + if (avahi_dns_packet_consume_bytes(p, &r->data.a.address, sizeof(AvahiIPv4Address)) < 0) + goto fail; + + break; + + case AVAHI_DNS_TYPE_AAAA: + +/* g_message("aaaa"); */ + + if (avahi_dns_packet_consume_bytes(p, &r->data.aaaa.address, sizeof(AvahiIPv6Address)) < 0) + goto fail; + break; - } default: +/* g_message("generic"); */ + if (rdlength > 0) { - if (!(data = flx_dns_packet_get_rptr(p)) || - flx_dns_packet_skip(p, rdlength) < 0) - return NULL; - } else - data = NULL; + r->data.generic.data = g_memdup(avahi_dns_packet_get_rptr(p), rdlength); + + if (avahi_dns_packet_skip(p, rdlength) < 0) + goto fail; + } break; } - *ret_cache_flush = !!(class & MDNS_CACHE_FLUSH); - class &= ~ MDNS_CACHE_FLUSH; +/* g_message("%i == %u ?", (guint8*) avahi_dns_packet_get_rptr(p) - (guint8*) start, rdlength); */ + + /* Check if we read enough data */ + if ((guint8*) avahi_dns_packet_get_rptr(p) - (guint8*) start != rdlength) + goto fail; + + r->ttl = ttl; + + return r; - return flx_record_new_full(name, class, type, data, rdlength, ttl); +fail: + if (r) + avahi_record_unref(r); + + return NULL; } -flxKey* flx_dns_packet_consume_key(flxDnsPacket *p) { +AvahiKey* avahi_dns_packet_consume_key(AvahiDnsPacket *p, gboolean *ret_unicast_response) { gchar name[256]; guint16 type, class; g_assert(p); + g_assert(ret_unicast_response); - if (flx_dns_packet_consume_name(p, name, sizeof(name)) < 0 || - flx_dns_packet_consume_uint16(p, &type) < 0 || - flx_dns_packet_consume_uint16(p, &class) < 0) + if (avahi_dns_packet_consume_name(p, name, sizeof(name)) < 0 || + avahi_dns_packet_consume_uint16(p, &type) < 0 || + avahi_dns_packet_consume_uint16(p, &class) < 0) return NULL; - class &= ~ MDNS_CACHE_FLUSH; + *ret_unicast_response = !!(class & AVAHI_DNS_UNICAST_RESPONSE); + class &= ~AVAHI_DNS_UNICAST_RESPONSE; - return flx_key_new(name, class, type); + return avahi_key_new(name, class, type); } -guint8* flx_dns_packet_append_key(flxDnsPacket *p, flxKey *k) { +guint8* avahi_dns_packet_append_key(AvahiDnsPacket *p, AvahiKey *k, gboolean unicast_response) { guint8 *t; + guint size; g_assert(p); g_assert(k); - if (!(t = flx_dns_packet_append_name(p, k->name)) || - !flx_dns_packet_append_uint16(p, k->type) || - !flx_dns_packet_append_uint16(p, k->class)) + size = p->size; + + if (!(t = avahi_dns_packet_append_name(p, k->name)) || + !avahi_dns_packet_append_uint16(p, k->type) || + !avahi_dns_packet_append_uint16(p, k->class | (unicast_response ? AVAHI_DNS_UNICAST_RESPONSE : 0))) { + p->size = size; return NULL; + } return t; } -guint8* flx_dns_packet_append_record(flxDnsPacket *p, flxRecord *r, gboolean cache_flush) { - guint8 *t; +guint8* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, gboolean cache_flush) { + guint8 *t, *l, *start; + guint size; g_assert(p); g_assert(r); - if (!(t = flx_dns_packet_append_name(p, r->key->name)) || - !flx_dns_packet_append_uint16(p, r->key->type) || - !flx_dns_packet_append_uint16(p, cache_flush ? (r->key->class | MDNS_CACHE_FLUSH) : (r->key->class &~ MDNS_CACHE_FLUSH)) || - !flx_dns_packet_append_uint32(p, r->ttl)) - return NULL; + size = p->size; + + if (!(t = avahi_dns_packet_append_name(p, r->key->name)) || + !avahi_dns_packet_append_uint16(p, r->key->type) || + !avahi_dns_packet_append_uint16(p, cache_flush ? (r->key->class | AVAHI_DNS_CACHE_FLUSH) : (r->key->class &~ AVAHI_DNS_CACHE_FLUSH)) || + !avahi_dns_packet_append_uint32(p, r->ttl) || + !(l = avahi_dns_packet_append_uint16(p, 0))) + goto fail; + + start = avahi_dns_packet_extend(p, 0); switch (r->key->type) { - case FLX_DNS_TYPE_PTR: - case FLX_DNS_TYPE_CNAME: { - char ptr_name[257]; + case AVAHI_DNS_TYPE_PTR: + case AVAHI_DNS_TYPE_CNAME : - g_assert((size_t) r->size+1 <= sizeof(ptr_name)); - memcpy(ptr_name, r->data, r->size); - ptr_name[r->size] = 0; + if (!(avahi_dns_packet_append_name(p, r->data.ptr.name))) + goto fail; - if (!flx_dns_packet_append_uint16(p, strlen(ptr_name)+1) || - !flx_dns_packet_append_name(p, ptr_name)) - return NULL; + break; + + case AVAHI_DNS_TYPE_SRV: + + if (!avahi_dns_packet_append_uint16(p, r->data.srv.priority) || + !avahi_dns_packet_append_uint16(p, r->data.srv.weight) || + !avahi_dns_packet_append_uint16(p, r->data.srv.port) || + !avahi_dns_packet_append_name(p, r->data.srv.name)) + goto fail; break; - } - case FLX_DNS_TYPE_SRV: { - char name[257]; + case AVAHI_DNS_TYPE_HINFO: + if (!avahi_dns_packet_append_string(p, r->data.hinfo.cpu) || + !avahi_dns_packet_append_string(p, r->data.hinfo.os)) + goto fail; - g_assert(r->size >= 6 && (size_t) r->size-6+1 <= sizeof(name)); - memcpy(name, r->data+6, r->size-6); - name[r->size-6] = 0; + break; - if (!flx_dns_packet_append_uint16(p, strlen(name+6)+1+6) || - !flx_dns_packet_append_bytes(p, r->data, 6) || - !flx_dns_packet_append_name(p, name)) - return NULL; + case AVAHI_DNS_TYPE_TXT: { + + guint8 *data; + guint size; + size = avahi_string_list_serialize(r->data.txt.string_list, NULL, 0); + +/* g_message("appending string: %u %p", size, r->data.txt.string_list); */ + + if (!(data = avahi_dns_packet_extend(p, size))) + goto fail; + + avahi_string_list_serialize(r->data.txt.string_list, data, size); break; } + + case AVAHI_DNS_TYPE_A: + + if (!avahi_dns_packet_append_bytes(p, &r->data.a.address, sizeof(r->data.a.address))) + goto fail; + + break; + + case AVAHI_DNS_TYPE_AAAA: + + if (!avahi_dns_packet_append_bytes(p, &r->data.aaaa.address, sizeof(r->data.aaaa.address))) + goto fail; + + break; + default: - if (!flx_dns_packet_append_uint16(p, r->size) || - (r->size != 0 && !flx_dns_packet_append_bytes(p, r->data, r->size))) - return NULL; + + if (r->data.generic.size && + avahi_dns_packet_append_bytes(p, r->data.generic.data, r->data.generic.size)) + goto fail; + + break; } + + + + size = avahi_dns_packet_extend(p, 0) - start; + g_assert(size <= 0xFFFF); + +/* g_message("appended %u", size); */ + + * (guint16*) l = g_htons((guint16) size); + return t; + + +fail: + p->size = size; + return NULL; +} + +gboolean avahi_dns_packet_is_empty(AvahiDnsPacket *p) { + g_assert(p); + + return p->size <= AVAHI_DNS_PACKET_HEADER_SIZE; +} + +guint avahi_dns_packet_space(AvahiDnsPacket *p) { + g_assert(p); + + g_assert(p->size <= p->max_size); + + return p->max_size - p->size; }