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-rw-r--r--dirmngr/dns-stuff.c256
-rw-r--r--dirmngr/dns-stuff.h15
-rw-r--r--dirmngr/http.c17
-rw-r--r--dirmngr/t-dns-stuff.c35
4 files changed, 299 insertions, 24 deletions
diff --git a/dirmngr/dns-stuff.c b/dirmngr/dns-stuff.c
index 3fa6054d3..c500c34e7 100644
--- a/dirmngr/dns-stuff.c
+++ b/dirmngr/dns-stuff.c
@@ -1,5 +1,5 @@
/* dns-stuff.c - DNS related code including CERT RR (rfc-4398)
- * Copyright (C) 2005, 2006, 2009 Free Software Foundation, Inc.
+ * Copyright (C) 2003, 2005, 2006, 2009 Free Software Foundation, Inc.
* Copyright (C) 2005, 2006, 2009, 2015 Werner Koch
*
* This file is part of GnuPG.
@@ -54,8 +54,11 @@
#include "host2net.h"
#include "dns-stuff.h"
-/* Not every installation has gotten around to supporting CERTs
- yet... */
+/* Not every installation has gotten around to supporting SRVs or
+ CERTs yet... */
+#ifndef T_SRV
+#define T_SRV 33
+#endif
#ifndef T_CERT
# define T_CERT 37
#endif
@@ -588,3 +591,250 @@ get_dns_cert (const char *name, int want_certtype,
return gpg_err_make (default_errsource, GPG_ERR_NOT_SUPPORTED);
#endif
}
+
+#ifdef USE_DNS_SRV
+static int
+priosort(const void *a,const void *b)
+{
+ const struct srventry *sa=a,*sb=b;
+ if(sa->priority>sb->priority)
+ return 1;
+ else if(sa->priority<sb->priority)
+ return -1;
+ else
+ return 0;
+}
+
+
+int
+getsrv (const char *name,struct srventry **list)
+{
+ int srvcount=0;
+ u16 count;
+ int i, rc;
+
+ *list = NULL;
+
+#ifdef USE_ADNS
+ {
+ adns_state state;
+ adns_answer *answer = NULL;
+
+ rc = adns_init (&state, adns_if_noerrprint, NULL);
+ if (rc)
+ {
+ log_error ("error initializing adns: %s\n", strerror (errno));
+ return -1;
+ }
+
+ rc = adns_synchronous (state, name, adns_r_srv, adns_qf_quoteok_query,
+ &answer);
+ if (rc)
+ {
+ log_error ("DNS query failed: %s\n", strerror (errno));
+ adns_finish (state);
+ return -1;
+ }
+ if (answer->status != adns_s_ok
+ || answer->type != adns_r_srv || !answer->nrrs)
+ {
+ log_error ("DNS query returned an error or no records: %s (%s)\n",
+ adns_strerror (answer->status),
+ adns_errabbrev (answer->status));
+ adns_free (answer);
+ adns_finish (state);
+ return 0;
+ }
+
+ for (count = 0; count < answer->nrrs; count++)
+ {
+ struct srventry *srv = NULL;
+ struct srventry *newlist;
+
+ if (strlen (answer->rrs.srvha[count].ha.host) >= MAXDNAME)
+ {
+ log_info ("hostname in SRV record too long - skipped\n");
+ continue;
+ }
+
+ newlist = xtryrealloc (*list, (srvcount+1)*sizeof(struct srventry));
+ if (!newlist)
+ goto fail;
+ *list = newlist;
+ memset (&(*list)[srvcount], 0, sizeof(struct srventry));
+ srv = &(*list)[srvcount];
+ srvcount++;
+
+ srv->priority = answer->rrs.srvha[count].priority;
+ srv->weight = answer->rrs.srvha[count].weight;
+ srv->port = answer->rrs.srvha[count].port;
+ strcpy (srv->target, answer->rrs.srvha[count].ha.host);
+ }
+
+ adns_free (answer);
+ adns_finish (state);
+ }
+#else /*!USE_ADNS*/
+ {
+ unsigned char answer[2048];
+ HEADER *header = (HEADER *)answer;
+ unsigned char *pt, *emsg;
+ int r;
+ u16 dlen;
+
+ r = res_query (name, C_IN, T_SRV, answer, sizeof answer);
+ if (r < sizeof (HEADER) || r > sizeof answer)
+ return -1;
+ if (header->rcode != NOERROR || !(count=ntohs (header->ancount)))
+ return 0; /* Error or no record found. */
+
+ emsg = &answer[r];
+ pt = &answer[sizeof(HEADER)];
+
+ /* Skip over the query */
+ rc = dn_skipname (pt, emsg);
+ if (rc == -1)
+ goto fail;
+
+ pt += rc + QFIXEDSZ;
+
+ while (count-- > 0 && pt < emsg)
+ {
+ struct srventry *srv=NULL;
+ u16 type,class;
+ struct srventry *newlist;
+
+ newlist = xtryrealloc (*list, (srvcount+1)*sizeof(struct srventry));
+ if (!newlist)
+ goto fail;
+ *list = newlist;
+ memset(&(*list)[srvcount],0,sizeof(struct srventry));
+ srv=&(*list)[srvcount];
+ srvcount++;
+
+ rc = dn_skipname(pt,emsg); /* the name we just queried for */
+ if (rc == -1)
+ goto fail;
+ pt+=rc;
+
+ /* Truncated message? */
+ if((emsg-pt)<16)
+ goto fail;
+
+ type = buf16_to_u16 (pt);
+ pt += 2;
+ /* We asked for SRV and got something else !? */
+ if(type!=T_SRV)
+ goto fail;
+
+ class = buf16_to_u16 (pt);
+ pt += 2;
+ /* We asked for IN and got something else !? */
+ if(class!=C_IN)
+ goto fail;
+
+ pt += 4; /* ttl */
+ dlen = buf16_to_u16 (pt);
+ pt += 2;
+
+ srv->priority = buf16_to_ushort (pt);
+ pt += 2;
+ srv->weight = buf16_to_ushort (pt);
+ pt += 2;
+ srv->port = buf16_to_ushort (pt);
+ pt += 2;
+
+ /* Get the name. 2782 doesn't allow name compression, but
+ dn_expand still works to pull the name out of the
+ packet. */
+ rc = dn_expand(answer,emsg,pt,srv->target,MAXDNAME);
+ if (rc == 1 && srv->target[0] == 0) /* "." */
+ {
+ xfree(*list);
+ *list = NULL;
+ return 0;
+ }
+ if (rc == -1)
+ goto fail;
+ pt += rc;
+ /* Corrupt packet? */
+ if (dlen != rc+6)
+ goto fail;
+ }
+ }
+#endif /*!USE_ADNS*/
+
+ /* Now we have an array of all the srv records. */
+
+ /* Order by priority */
+ qsort(*list,srvcount,sizeof(struct srventry),priosort);
+
+ /* For each priority, move the zero-weighted items first. */
+ for (i=0; i < srvcount; i++)
+ {
+ int j;
+
+ for (j=i;j < srvcount && (*list)[i].priority == (*list)[j].priority; j++)
+ {
+ if((*list)[j].weight==0)
+ {
+ /* Swap j with i */
+ if(j!=i)
+ {
+ struct srventry temp;
+
+ memcpy (&temp,&(*list)[j],sizeof(struct srventry));
+ memcpy (&(*list)[j],&(*list)[i],sizeof(struct srventry));
+ memcpy (&(*list)[i],&temp,sizeof(struct srventry));
+ }
+
+ break;
+ }
+ }
+ }
+
+ /* Run the RFC-2782 weighting algorithm. We don't need very high
+ quality randomness for this, so regular libc srand/rand is
+ sufficient. Fixme: It is a bit questionaly to reinitalize srand
+ - better use a gnupg fucntion for this. */
+ srand(time(NULL)*getpid());
+
+ for (i=0; i < srvcount; i++)
+ {
+ int j;
+ float prio_count=0,chose;
+
+ for (j=i; j < srvcount && (*list)[i].priority == (*list)[j].priority; j++)
+ {
+ prio_count+=(*list)[j].weight;
+ (*list)[j].run_count=prio_count;
+ }
+
+ chose=prio_count*rand()/RAND_MAX;
+
+ for (j=i;j<srvcount && (*list)[i].priority==(*list)[j].priority;j++)
+ {
+ if (chose<=(*list)[j].run_count)
+ {
+ /* Swap j with i */
+ if(j!=i)
+ {
+ struct srventry temp;
+
+ memcpy(&temp,&(*list)[j],sizeof(struct srventry));
+ memcpy(&(*list)[j],&(*list)[i],sizeof(struct srventry));
+ memcpy(&(*list)[i],&temp,sizeof(struct srventry));
+ }
+ break;
+ }
+ }
+ }
+
+ return srvcount;
+
+ fail:
+ xfree(*list);
+ *list=NULL;
+ return -1;
+}
+#endif /*USE_DNS_SRV*/
diff --git a/dirmngr/dns-stuff.h b/dirmngr/dns-stuff.h
index 090e79b4d..5ffa0178f 100644
--- a/dirmngr/dns-stuff.h
+++ b/dirmngr/dns-stuff.h
@@ -72,6 +72,20 @@ struct dns_addrinfo_s
+#ifndef MAXDNAME
+#define MAXDNAME 1025
+#endif
+
+struct srventry
+{
+ unsigned short priority;
+ unsigned short weight;
+ unsigned short port;
+ int run_count;
+ char target[MAXDNAME];
+};
+
+
/* Calling this function switches the DNS code into Tor mode if
possibe. Return 0 on success. */
gpg_error_t enable_dns_tormode (void);
@@ -89,6 +103,7 @@ gpg_error_t get_dns_cert (const char *name, int want_certtype,
unsigned char **r_fpr, size_t *r_fprlen,
char **r_url);
+int getsrv (const char *name,struct srventry **list);
#endif /*GNUPG_DIRMNGR_DNS_STUFF_H*/
diff --git a/dirmngr/http.c b/dirmngr/http.c
index 19d5f8f21..4387b96b5 100644
--- a/dirmngr/http.c
+++ b/dirmngr/http.c
@@ -100,23 +100,6 @@
#include "i18n.h"
#include "dns-stuff.h"
#include "http.h"
-#ifdef USE_DNS_SRV
-# include "srv.h"
-#else /*!USE_DNS_SRV*/
- /* If we are not compiling with SRV record support we provide stub
- data structures. */
-# ifndef MAXDNAME
-# define MAXDNAME 1025
-# endif
-struct srventry
-{
- unsigned short priority;
- unsigned short weight;
- unsigned short port;
- int run_count;
- char target[MAXDNAME];
-};
-#endif/*!USE_DNS_SRV*/
#ifdef USE_NPTH
diff --git a/dirmngr/t-dns-stuff.c b/dirmngr/t-dns-stuff.c
index e8a74eacc..d2ead8f03 100644
--- a/dirmngr/t-dns-stuff.c
+++ b/dirmngr/t-dns-stuff.c
@@ -41,10 +41,13 @@ main (int argc, char **argv)
{
int last_argc = -1;
gpg_error_t err;
+ int any_options = 0;
int opt_cert = 0;
- char const *name;
+ int opt_srv = 0;
+ char const *name = NULL;
gpgrt_init ();
+ log_set_prefix (PGM, GPGRT_LOG_WITH_PREFIX);
if (argc)
{ argc--; argv++; }
while (argc && last_argc != argc )
@@ -62,6 +65,7 @@ main (int argc, char **argv)
" --verbose print timings etc.\n"
" --debug flyswatter\n"
" --cert lookup a CERT RR\n"
+ " --srv lookup a SRV RR\n"
, stdout);
exit (0);
}
@@ -78,7 +82,12 @@ main (int argc, char **argv)
}
else if (!strcmp (*argv, "--cert"))
{
- opt_cert = 1;
+ any_options = opt_cert = 1;
+ argc--; argv++;
+ }
+ else if (!strcmp (*argv, "--srv"))
+ {
+ any_options = opt_srv = 1;
argc--; argv++;
}
else if (!strncmp (*argv, "--", 2))
@@ -88,7 +97,7 @@ main (int argc, char **argv)
}
}
- if (!argc)
+ if (!argc && !any_options)
{
opt_cert = 1;
name = "simon.josefsson.org";
@@ -97,7 +106,7 @@ main (int argc, char **argv)
name = *argv;
else
{
- fprintf (stderr, PGM ": too many host names given\n");
+ fprintf (stderr, PGM ": none or too many host names given\n");
exit (1);
}
@@ -145,6 +154,24 @@ main (int argc, char **argv)
xfree (fpr);
xfree (url);
}
+ else if (opt_srv)
+ {
+ struct srventry *srv;
+ int rc,i;
+
+ rc=getsrv("_hkp._tcp.wwwkeys.pgp.net",&srv);
+ printf("Count=%d\n\n",rc);
+ for(i=0;i<rc;i++)
+ {
+ printf("priority=%hu\n",srv[i].priority);
+ printf("weight=%hu\n",srv[i].weight);
+ printf("port=%hu\n",srv[i].port);
+ printf("target=%s\n",srv[i].target);
+ printf("\n");
+ }
+
+ xfree(srv);
+ }
else /* Standard lookup. */
{
char *cname;
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-03 23:41:06 +0000