Pass on all clients, add hosts support wherever applicable

Signed-off-by: Laurent Bercot <ska@appnovation.com>

18 files changed, 299 insertions, 136 deletions

diff --git a/src/clients/s6-dnsip.c b/src/clients/s6-dnsip.c
index 9828443..6a5747d 100644
--- a/src/clients/s6-dnsip.c
+++ b/src/clients/s6-dnsip.c
@@ -11,49 +11,73 @@
 #include <skalibs/buffer.h>
 #include <skalibs/tai.h>
 #include <skalibs/random.h>
-#include <s6-dns/s6dns.h>
 
-#define USAGE "s6-dnsip [ -q ] [ -r ] [ -t timeout ] domain"
+#include <s6-dns/s6dns-rci.h>
+#include <s6-dns/hosts.h>
+#include <s6-dns/s6dns-resolve.h>
+
+#define USAGE "s6-dnsip [ -q ] [ -H | -h ] [ -r ] [ -t timeout ] domain"
 #define dieusage() strerr_dieusage(100, USAGE)
 
 int main (int argc, char const *const *argv)
 {
   genalloc ips = GENALLOC_ZERO ;  /* ip46full */
   tain deadline ;
-  size_t i = 0 ;
   unsigned int t = 0 ;
   int flagqualify = 0 ;
+  int flaghosts = 0 ;
   int flagunsort = 0 ;
+  int r = 0 ;
   PROG = "s6-dnsip" ;
 
-  for (;;)
   {
-    int opt = lgetopt(argc, argv, "qrt:") ;
-    if (opt == -1) break ;
-    switch (opt)
+    subgetopt l = SUBGETOPT_ZERO ;
+    for (;;)
     {
-      case 'q' : flagqualify = 1 ; break ;
-      case 'r' : flagunsort = 1 ; break ;
-      case 't' : if (!uint0_scan(subgetopt_here.arg, &t)) dieusage() ; break ;
-      default : dieusage() ;
+      int opt = subgetopt_r(argc, argv, "qHhrt:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'q' : flagqualify = 1 ; break ;
+        case 'H' : flaghosts = 0 ; break ;
+        case 'h' : flaghosts = 1 ; break ;
+        case 'r' : flagunsort = 1 ; break ;
+        case 't' : if (!uint0_scan(l.arg, &t)) dieusage() ; break ;
+        default : dieusage() ;
+      }
     }
+    argc -= l.ind ; argv += l.ind ;
   }
-  argc -= subgetopt_here.ind ; argv += subgetopt_here.ind ;
   if (argc < 1) dieusage() ;
 
   tain_now_set_stopwatch_g() ;
   if (t) tain_from_millisecs(&deadline, t) ; else deadline = tain_infinite_relative ;
   tain_add_g(&deadline, &deadline) ;
-  if (!s6dns_init()) strerr_diefu1sys(111, "s6dns_init") ;
+
+  if (!s6dns_rci_init(&s6dns_rci_here, "/etc/resolv.conf"))
+    strerr_diefu1sys(111, "initialize structures from /etc/resolv.conf") ;
+  if (flaghosts)
+  {
+    flaghosts = s6dns_hosts_init(&s6dns_hosts_here, "/etc/hosts", "/etc/hosts.cdb", "/tmp/hosts.cdb") ;
+    if (flaghosts == -1) strerr_diefu1sys(111, "initialize hosts database from /etc/hosts or /etc/hosts.cdb") ;
+  }
+
+  if (flaghosts)
   {
-    int r = s6dns_resolve_aaaaa_g(&ips, argv[0], strlen(argv[0]), flagqualify, &deadline) ;
+    r = flagqualify ? s6dns_hosts_aaaaa_q(argv[0], &ips) : s6dns_hosts_aaaaa_noq(argv[0], &ips) ;
+    if (r == -1) strerr_diefu3sys(111, "look up ", argv[0], " in hosts database") ;
+  }
+
+  if (!r)
+  {
+    r = s6dns_resolve_aaaaa_g(&ips, argv[0], strlen(argv[0]), flagqualify, &deadline) ;
     if (r < 0) strerr_diefu2sys((errno == ETIMEDOUT) ? 99 : 111, "resolve ", argv[0]) ;
-    if (!r && errno) strerr_diefu4x(2, "resolve ", argv[0], ": ", s6dns_constants_error_str(errno)) ;
+    if (!r) strerr_diefu4x(2, "resolve ", argv[0], ": ", s6dns_constants_error_str(errno)) ;
   }
-  if (!genalloc_len(ip46full, &ips)) return 1 ;
 
+  if (!genalloc_len(ip46full, &ips)) return 1 ;
   if (flagunsort) random_unsort(ips.s, genalloc_len(ip46full, &ips), sizeof(ip46full)) ;
-  for (i = 0 ; i < genalloc_len(ip46full, &ips) ; i++)
+  for (size_t i = 0 ; i < genalloc_len(ip46full, &ips) ; i++)
   {
     char fmt[IP6_FMT] ;
     size_t n = ip46full_fmt(fmt, genalloc_s(ip46full, &ips) + i) ;
diff --git a/src/clients/s6-dnsip4-filter.c b/src/clients/s6-dnsip4-filter.c
index 4842734..dbfc82b 100644
--- a/src/clients/s6-dnsip4-filter.c
+++ b/src/clients/s6-dnsip4-filter.c
@@ -1,9 +1,11 @@
 /* ISC license. */
 
 #include <string.h>
+
 #include <skalibs/fmtscan.h>
 #include <skalibs/strerr.h>
 #include <skalibs/stralloc.h>
+
 #include <s6-dns/s6dns-constants.h>
 #include <s6-dns/s6dns-message.h>
 #include "s6dns-generic-filter.h"
diff --git a/src/clients/s6-dnsip4.c b/src/clients/s6-dnsip4.c
index db32804..370c006 100644
--- a/src/clients/s6-dnsip4.c
+++ b/src/clients/s6-dnsip4.c
@@ -2,6 +2,7 @@
 
 #include <string.h>
 #include <errno.h>
+
 #include <skalibs/types.h>
 #include <skalibs/sgetopt.h>
 #include <skalibs/strerr.h>
@@ -9,53 +10,78 @@
 #include <skalibs/buffer.h>
 #include <skalibs/tai.h>
 #include <skalibs/random.h>
-#include <s6-dns/s6dns.h>
 
-#define USAGE "s6-dnsip4 [ -q ] [ -r ] [ -t timeout ] domain"
+#include <s6-dns/s6dns-rci.h>
+#include <s6-dns/hosts.h>
+#include <s6-dns/s6dns-resolve.h>
+
+#define USAGE "s6-dnsip4 [ -q ] [ -H | -h ] [ -r ] [ -t timeout ] domain"
 #define dieusage() strerr_dieusage(100, USAGE)
 
 int main (int argc, char const *const *argv)
 {
   stralloc ips = STRALLOC_ZERO ;
   tain deadline ;
-  size_t i = 0 ;
   unsigned int t = 0 ;
   int flagqualify = 0 ;
+  int flaghosts = 0 ;
   int flagunsort = 0 ;
+  int r = 0 ;
   PROG = "s6-dnsip4" ;
 
-  for (;;)
   {
-    int opt = lgetopt(argc, argv, "qrt:") ;
-    if (opt == -1) break ;
-    switch (opt)
+    subgetopt l = SUBGETOPT_ZERO ;
+    for (;;)
     {
-      case 'q' : flagqualify = 1 ; break ;
-      case 'r' : flagunsort = 1 ; break ;
-      case 't' : if (!uint0_scan(subgetopt_here.arg, &t)) dieusage() ; break ;
-      default : dieusage() ;
+      int opt = subgetopt_r(argc, argv, "qHhrt:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'q' : flagqualify = 1 ; break ;
+        case 'H' : flaghosts = 0 ; break ;
+        case 'h' : flaghosts = 1 ; break ;
+        case 'r' : flagunsort = 1 ; break ;
+        case 't' : if (!uint0_scan(l.arg, &t)) dieusage() ; break ;
+        default : dieusage() ;
+      }
     }
+    argc -= l.ind ; argv += l.ind ;
   }
-  argc -= subgetopt_here.ind ; argv += subgetopt_here.ind ;
   if (argc < 1) dieusage() ;
 
   tain_now_set_stopwatch_g() ;
   if (t) tain_from_millisecs(&deadline, t) ; else deadline = tain_infinite_relative ;
   tain_add_g(&deadline, &deadline) ;
-  if (!s6dns_init()) strerr_diefu1sys(111, "s6dns_init") ;
+
+  if (!s6dns_rci_init(&s6dns_rci_here, "/etc/resolv.conf"))
+    strerr_diefu1sys(111, "initialize structures from /etc/resolv.conf") ;
+  if (flaghosts)
+  {
+    flaghosts = s6dns_hosts_init(&s6dns_hosts_here, "/etc/hosts", "/etc/hosts.cdb", "/tmp/hosts.cdb") ;
+    if (flaghosts == -1) strerr_diefu1sys(111, "initialize hosts database from /etc/hosts or /etc/hosts.cdb") ;
+  }
+
+  if (flaghosts)
   {
-    int r = s6dns_resolve_a_g(&ips, argv[0], strlen(argv[0]), flagqualify, &deadline) ;
-    if (r < 0) strerr_diefu2sys((errno == ETIMEDOUT) ? 99 : 111, "resolve ", argv[0]) ;
+    r = flagqualify ? s6dns_hosts_a_q(argv[0], &ips) : s6dns_hosts_a_noq(argv[0], &ips) ;
+    if (r == -1) strerr_diefu3sys(111, "look up ", argv[0], " in hosts database") ;
+  }
+
+  if (!r)
+  {
+    r = s6dns_resolve_a_g(&ips, argv[0], strlen(argv[0]), flagqualify, &deadline) ;
+    if (r == -1) strerr_diefu2sys((errno == ETIMEDOUT) ? 99 : 111, "resolve ", argv[0]) ;
     if (!r) strerr_diefu4x(2, "resolve ", argv[0], ": ", s6dns_constants_error_str(errno)) ;
   }
+
   if (!ips.len) return 1 ;
   if (flagunsort) random_unsort(ips.s, ips.len / 4, 4) ;
-  for (i = 0 ; i < ips.len / 4 ; i++)
+  for (size_t i = 0 ; i < ips.len / 4 ; i++)
   {
     char fmt[IP4_FMT] ;
     size_t n = ip4_fmt(fmt, ips.s + 4 * i) ;
     fmt[n++] = '\n' ;
-    if (buffer_put(buffer_1small, fmt, n) < (ssize_t)n)
+    if (buffer_put(buffer_1small, fmt, n) == -1)
       strerr_diefu1sys(111, "write to stdout") ;
   }
   if (!buffer_flush(buffer_1small))
diff --git a/src/clients/s6-dnsip6-filter.c b/src/clients/s6-dnsip6-filter.c
index d2855bc..a7840f7 100644
--- a/src/clients/s6-dnsip6-filter.c
+++ b/src/clients/s6-dnsip6-filter.c
@@ -1,9 +1,11 @@
 /* ISC license. */
 
 #include <string.h>
+
 #include <skalibs/fmtscan.h>
 #include <skalibs/strerr.h>
 #include <skalibs/stralloc.h>
+
 #include <s6-dns/s6dns-constants.h>
 #include <s6-dns/s6dns-message.h>
 #include "s6dns-generic-filter.h"
diff --git a/src/clients/s6-dnsip6.c b/src/clients/s6-dnsip6.c
index eb37a53..2fb2f6f 100644
--- a/src/clients/s6-dnsip6.c
+++ b/src/clients/s6-dnsip6.c
@@ -2,6 +2,7 @@
 
 #include <string.h>
 #include <errno.h>
+
 #include <skalibs/types.h>
 #include <skalibs/sgetopt.h>
 #include <skalibs/strerr.h>
@@ -9,48 +10,73 @@
 #include <skalibs/buffer.h>
 #include <skalibs/tai.h>
 #include <skalibs/random.h>
-#include <s6-dns/s6dns.h>
 
-#define USAGE "s6-dnsip6 [ -q ] [ -r ] [ -t timeout ] domain"
+#include <s6-dns/s6dns-rci.h>
+#include <s6-dns/hosts.h>
+#include <s6-dns/s6dns-resolve.h>
+
+#define USAGE "s6-dnsip6 [ -q ] [ -H | -h ] [ -r ] [ -t timeout ] domain"
 #define dieusage() strerr_dieusage(100, USAGE)
 
 int main (int argc, char const *const *argv)
 {
   stralloc ips = STRALLOC_ZERO ;
   tain deadline ;
-  size_t i = 0 ;
   unsigned int t = 0 ;
   int flagqualify = 0 ;
+  int flaghosts = 0 ;
   int flagunsort = 0 ;
+  int r = 0 ;
   PROG = "s6-dnsip6" ;
 
-  for (;;)
   {
-    int opt = lgetopt(argc, argv, "qrt:") ;
-    if (opt == -1) break ;
-    switch (opt)
+    subgetopt l = SUBGETOPT_ZERO ;
+    for (;;)
     {
-      case 'q' : flagqualify = 1 ; break ;
-      case 'r' : flagunsort = 1 ; break ;
-      case 't' : if (!uint0_scan(subgetopt_here.arg, &t)) dieusage() ; break ;
-      default : dieusage() ;
+      int opt = subgetopt_r(argc, argv, "qHhrt:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'q' : flagqualify = 1 ; break ;
+        case 'H' : flaghosts = 0 ; break ;
+        case 'h' : flaghosts = 1 ; break ;
+        case 'r' : flagunsort = 1 ; break ;
+        case 't' : if (!uint0_scan(l.arg, &t)) dieusage() ; break ;
+        default : dieusage() ;
+      }
     }
+    argc -= l.ind ; argv += l.ind ;
   }
-  argc -= subgetopt_here.ind ; argv += subgetopt_here.ind ;
   if (argc < 1) dieusage() ;
 
   tain_now_set_stopwatch_g() ;
   if (t) tain_from_millisecs(&deadline, t) ; else deadline = tain_infinite_relative ;
   tain_add_g(&deadline, &deadline) ;
-  if (!s6dns_init()) strerr_diefu1sys(111, "s6dns_init") ;
+
+  if (!s6dns_rci_init(&s6dns_rci_here, "/etc/resolv.conf"))
+    strerr_diefu1sys(111, "initialize structures from /etc/resolv.conf") ;
+  if (flaghosts)
+  {
+    flaghosts = s6dns_hosts_init(&s6dns_hosts_here, "/etc/hosts", "/etc/hosts.cdb", "/tmp/hosts.cdb") ;
+    if (flaghosts == -1) strerr_diefu1sys(111, "initialize hosts database from /etc/hosts or /etc/hosts.cdb") ;
+  }
+
+  if (flaghosts)
   {
-    int r = s6dns_resolve_aaaa_g(&ips, argv[0], strlen(argv[0]), flagqualify, &deadline) ;
-    if (r < 0) strerr_diefu2sys((errno == ETIMEDOUT) ? 99 : 111, "resolve ", argv[0]) ;
+    r = flagqualify ? s6dns_hosts_aaaa_q(argv[0], &ips) : s6dns_hosts_aaaa_noq(argv[0], &ips) ;
+    if (r == -1) strerr_diefu3sys(111, "look up ", argv[0], " in hosts database") ;
+  }
+
+  if (!r)
+  {
+    r = s6dns_resolve_aaaa_g(&ips, argv[0], strlen(argv[0]), flagqualify, &deadline) ;
+    if (r == -1) strerr_diefu2sys((errno == ETIMEDOUT) ? 99 : 111, "resolve ", argv[0]) ;
     if (!r) strerr_diefu4x(2, "resolve ", argv[0], ": ", s6dns_constants_error_str(errno)) ;
   }
+
   if (!ips.len) return 1 ;
   if (flagunsort) random_unsort(ips.s, ips.len / 16, 16) ;
-  for (i = 0 ; i < ips.len / 16 ; i++)
+  for (size_t i = 0 ; i < ips.len / 16 ; i++)
   {
     char fmt[IP6_FMT] ;
     size_t n = ip6_fmt(fmt, ips.s + 16 * i) ;
diff --git a/src/clients/s6-dnsmx.c b/src/clients/s6-dnsmx.c
index 159a5c6..356eb4b 100644
--- a/src/clients/s6-dnsmx.c
+++ b/src/clients/s6-dnsmx.c
@@ -2,6 +2,7 @@
 
 #include <string.h>
 #include <errno.h>
+
 #include <skalibs/types.h>
 #include <skalibs/sgetopt.h>
 #include <skalibs/strerr.h>
@@ -9,6 +10,7 @@
 #include <skalibs/tai.h>
 #include <skalibs/genalloc.h>
 #include <skalibs/random.h>
+
 #include <s6-dns/s6dns.h>
 
 #define USAGE "s6-dnsmx [ -q ] [ -r ] [ -t timeout ] name"
@@ -18,38 +20,43 @@ int main (int argc, char const *const *argv)
 {
   genalloc mxs = GENALLOC_ZERO ; /* array of s6dns_message_rr_mx_t */
   tain deadline ;
-  size_t i = 0 ;
   unsigned int t = 0 ;
   int flagqualify = 0 ;
   int flagunsort = 0 ;
+  int r ;
   PROG = "s6-dnsmx" ;
-  for (;;)
+
   {
-    int opt = lgetopt(argc, argv, "qrt:") ;
-    if (opt == -1) break ;
-    switch (opt)
+    subgetopt l = SUBGETOPT_ZERO ;
+    for (;;)
     {
-      case 'q' : flagqualify = 1 ; break ;
-      case 'r' : flagunsort = 1 ; break ;
-      case 't' : if (!uint0_scan(subgetopt_here.arg, &t)) dieusage() ; break ;
-      default : dieusage() ;
+      int opt = subgetopt_r(argc, argv, "qrt:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'q' : flagqualify = 1 ; break ;
+        case 'r' : flagunsort = 1 ; break ;
+        case 't' : if (!uint0_scan(l.arg, &t)) dieusage() ; break ;
+        default : dieusage() ;
+      }
     }
+    argc -= l.ind ; argv += l.ind ;
   }
-  argc -= subgetopt_here.ind ; argv += subgetopt_here.ind ;
   if (argc < 1) dieusage() ;
 
   tain_now_set_stopwatch_g() ;
   if (t) tain_from_millisecs(&deadline, t) ; else deadline = tain_infinite_relative ;
   tain_add_g(&deadline, &deadline) ;
-  if (!s6dns_init()) strerr_diefu1sys(111, "s6dns_init") ;
-  {
-    int r = s6dns_resolve_mx_g(&mxs, argv[0], strlen(argv[0]), flagqualify, &deadline) ;
-    if (r < 0) strerr_diefu2sys((errno == ETIMEDOUT) ? 99 : 111, "resolve ", argv[0]) ;
-    if (!r) strerr_diefu4x(2, "resolve ", argv[0], ": ", s6dns_constants_error_str(errno)) ;
-  }
+
+  if (!s6dns_rci_init(&s6dns_rci_here, "/etc/resolv.conf"))
+    strerr_diefu1sys(111, "initialize structures from /etc/resolv.conf") ;
+
+  r = s6dns_resolve_mx_g(&mxs, argv[0], strlen(argv[0]), flagqualify, &deadline) ;
+  if (r < 0) strerr_diefu2sys((errno == ETIMEDOUT) ? 99 : 111, "resolve ", argv[0]) ;
+  if (!r) strerr_diefu4x(2, "resolve ", argv[0], ": ", s6dns_constants_error_str(errno)) ;
   if (!genalloc_len(s6dns_message_rr_mx_t, &mxs)) return 1 ;
   if (flagunsort) random_unsort(mxs.s, genalloc_len(s6dns_message_rr_mx_t, &mxs), sizeof(s6dns_message_rr_mx_t)) ;
-  for (i = 0 ; i < genalloc_len(s6dns_message_rr_mx_t, &mxs) ; i++)
+  for (size_t i = 0 ; i < genalloc_len(s6dns_message_rr_mx_t, &mxs) ; i++)
   {
     char buf[S6DNS_FMT_MX] ;
     size_t len = s6dns_fmt_mx(buf, S6DNS_FMT_MX, genalloc_s(s6dns_message_rr_mx_t, &mxs) + i) ;
diff --git a/src/clients/s6-dnsname.c b/src/clients/s6-dnsname.c
index c35751b..7c35f06 100644
--- a/src/clients/s6-dnsname.c
+++ b/src/clients/s6-dnsname.c
@@ -2,6 +2,7 @@
 
 #include <sys/types.h>
 #include <errno.h>
+
 #include <skalibs/types.h>
 #include <skalibs/sgetopt.h>
 #include <skalibs/strerr.h>
@@ -11,9 +12,10 @@
 #include <skalibs/genalloc.h>
 #include <skalibs/ip46.h>
 #include <skalibs/random.h>
+
 #include <s6-dns/s6dns.h>
 
-#define USAGE "s6-dnsname [ -4 | -6 ] [ -r ] [ -t timeout ] ip"
+#define USAGE "s6-dnsname [ -4 | -6 ] [ -H | -h ] [ -r ] [ -t timeout ] ip"
 #define dieusage() strerr_dieusage(100, USAGE)
 
 int main (int argc, char const *const *argv)
@@ -22,25 +24,33 @@ int main (int argc, char const *const *argv)
   tain deadline ;
   ip46full ip = IP46FULL_ZERO ;
   unsigned int t = 0 ;
+  int flaghosts = 0 ;
   int flagunsort = 0 ;
   int do4 = 0 ;
   int do6 = 0 ;
   PROG = "s6-dnsname" ;
-  for (;;)
+
   {
-    int opt = lgetopt(argc, argv, "46rt:") ;
-    if (opt == -1) break ;
-    switch (opt)
+    subgetopt l = SUBGETOPT_ZERO ;
+    for (;;)
     {
-      case '4' : do4 = 1 ; break ;
-      case '6' : do6 = 1 ; break ;
-      case 'r' : flagunsort = 1 ; break ;
-      case 't' : if (!uint0_scan(subgetopt_here.arg, &t)) dieusage() ; break ;
-      default : dieusage() ;
+      int opt = subgetopt_r(argc, argv, "46Hhrt:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case '4' : do4 = 1 ; break ;
+        case '6' : do6 = 1 ; break ;
+        case 'H' : flaghosts = 0 ; break ;
+        case 'h' : flaghosts = 1 ; break ;
+        case 'r' : flagunsort = 1 ; break ;
+        case 't' : if (!uint0_scan(l.arg, &t)) dieusage() ; break ;
+        default : dieusage() ;
+      }
     }
+    argc -= l.ind ; argv += l.ind ;
   }
-  argc -= subgetopt_here.ind ; argv += subgetopt_here.ind ;
   if (argc < 1) dieusage() ;
+
   if (!do4 && !do6) do4 = do6 = 1 ;
   if (do4 && do6)
   {
@@ -56,12 +66,38 @@ int main (int argc, char const *const *argv)
   tain_now_set_stopwatch_g() ;
   if (t) tain_from_millisecs(&deadline, t) ; else deadline = tain_infinite_relative ;
   tain_add_g(&deadline, &deadline) ;
-  if (!s6dns_init()) strerr_diefu1sys(111, "s6dns_init") ;
+
+  if (!s6dns_rci_init(&s6dns_rci_here, "/etc/resolv.conf"))
+    strerr_diefu1sys(111, "initialize structures from /etc/resolv.conf") ;
+  if (flaghosts)
+  {
+    flaghosts = s6dns_hosts_init(&s6dns_hosts_here, "/etc/hosts", "/etc/hosts.cdb", "/tmp/hosts.cdb") ;
+    if (flaghosts == -1) strerr_diefu1sys(111, "initialize hosts database from /etc/hosts or /etc/hosts.cdb") ;
+  }
+
+  if (flaghosts)
+  {
+    stralloc sa = STRALLOC_ZERO ;
+    int r = s6dns_hosts_name(ip.ip, &sa, &ds, ip.is6) ;
+    if (r == -1) strerr_diefu3sys(111, "look up ", argv[0], " in hosts database") ;
+    if (r)
+    {
+      for (size_t i = 0 ; i < genalloc_len(size_t, &ds) ; i++)
+      {
+        if (buffer_puts(buffer_1, sa.s + genalloc_s(size_t, &ds)[i]) < 0
+         || buffer_put(buffer_1, "\n", 1) < 0) goto err ;
+      }
+      if (!buffer_flush(buffer_1)) goto err ;
+      return 0 ;
+    }
+  }
+
   {
     int r = ip.is6 ? s6dns_resolve_name6_g(&ds, ip.ip, &deadline) : s6dns_resolve_name4_g(&ds, ip.ip, &deadline) ;
     if (r < 0) strerr_diefu2sys((errno == ETIMEDOUT) ? 99 : 111, "resolve ", argv[0]) ;
     if (!r) strerr_diefu4x(2, "resolve ", argv[0], ": ", s6dns_constants_error_str(errno)) ;
   }
+
   if (!genalloc_len(s6dns_domain_t, &ds)) return 1 ;
   if (flagunsort) random_unsort(ds.s, genalloc_len(s6dns_domain_t, &ds), sizeof(s6dns_domain_t)) ;
   {
@@ -72,6 +108,7 @@ int main (int argc, char const *const *argv)
   }
   if (buffer_putflush(buffer_1, "\n", 1) < 1) goto err ;
   return 0 ;
+
  err:
   strerr_diefu1sys(111, "write to stdout") ;
 }
diff --git a/src/clients/s6-dnsns.c b/src/clients/s6-dnsns.c
index 88f5197..7e19caf 100644
--- a/src/clients/s6-dnsns.c
+++ b/src/clients/s6-dnsns.c
@@ -3,6 +3,7 @@
 #include <sys/types.h>
 #include <string.h>
 #include <errno.h>
+
 #include <skalibs/types.h>
 #include <skalibs/sgetopt.h>
 #include <skalibs/strerr.h>
@@ -10,6 +11,7 @@
 #include <skalibs/tai.h>
 #include <skalibs/genalloc.h>
 #include <skalibs/random.h>
+
 #include <s6-dns/s6dns.h>
 
 #define USAGE "s6-dnsns [ -q ] [ -r ] [ -t timeout ] name"
@@ -22,31 +24,37 @@ int main (int argc, char const *const *argv)
   unsigned int t = 0 ;
   int flagqualify = 0 ;
   int flagunsort = 0 ;
+  int r ;
   PROG = "s6-dnsns" ;
-  for (;;)
+
   {
-    int opt = lgetopt(argc, argv, "qrt:") ;
-    if (opt == -1) break ;
-    switch (opt)
+    subgetopt l = SUBGETOPT_ZERO ;
+    for (;;)
     {
-      case 'q' : flagqualify = 1 ; break ;
-      case 'r' : flagunsort = 1 ; break ;
-      case 't' : if (!uint0_scan(subgetopt_here.arg, &t)) dieusage() ; break ;
-      default : dieusage() ;
+      int opt = subgetopt_r(argc, argv, "qrt:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'q' : flagqualify = 1 ; break ;
+        case 'r' : flagunsort = 1 ; break ;
+        case 't' : if (!uint0_scan(l.arg, &t)) dieusage() ; break ;
+        default : dieusage() ;
+      }
     }
+    argc -= l.ind ; argv += l.ind ;
   }
-  argc -= subgetopt_here.ind ; argv += subgetopt_here.ind ;
   if (argc < 1) dieusage() ;
 
   tain_now_set_stopwatch_g() ;
   if (t) tain_from_millisecs(&deadline, t) ; else deadline = tain_infinite_relative ;
   tain_add_g(&deadline, &deadline) ;
-  if (!s6dns_init()) strerr_diefu1sys(111, "s6dns_init") ;
-  {
-    int r = s6dns_resolve_ns_g(&ds, argv[0], strlen(argv[0]), flagqualify, &deadline) ;
-    if (r < 0) strerr_diefu2sys((errno == ETIMEDOUT) ? 99 : 111, "resolve ", argv[0]) ;
-    if (!r) strerr_diefu4x(2, "resolve ", argv[0], ": ", s6dns_constants_error_str(errno)) ;
-  }
+
+  if (!s6dns_rci_init(&s6dns_rci_here, "/etc/resolv.conf"))
+    strerr_diefu1sys(111, "initialize structures from /etc/resolv.conf") ;
+
+  r = s6dns_resolve_ns_g(&ds, argv[0], strlen(argv[0]), flagqualify, &deadline) ;
+  if (r == -1) strerr_diefu2sys((errno == ETIMEDOUT) ? 99 : 111, "resolve ", argv[0]) ;
+  if (!r) strerr_diefu4x(2, "resolve ", argv[0], ": ", s6dns_constants_error_str(errno)) ;
   if (!genalloc_len(s6dns_domain_t, &ds)) return 1 ;
   if (flagunsort) random_unsort(ds.s, genalloc_len(s6dns_domain_t, &ds), sizeof(s6dns_domain_t)) ;
   {
diff --git a/src/clients/s6-dnsq.c b/src/clients/s6-dnsq.c
index c6d50cf..6f85c42 100644
--- a/src/clients/s6-dnsq.c
+++ b/src/clients/s6-dnsq.c
@@ -3,6 +3,7 @@
 #include <string.h>
 #include <stdint.h>
 #include <errno.h>
+
 #include <skalibs/types.h>
 #include <skalibs/bitarray.h>
 #include <skalibs/strerr.h>
@@ -11,6 +12,7 @@
 #include <skalibs/genwrite.h>
 #include <skalibs/tai.h>
 #include <skalibs/ip46.h>
+
 #include <s6-dns/s6dns.h>
 #include <s6-dns/s6dns-analyze.h>
 #include <s6-dns/s6dns-debug.h>
@@ -60,11 +62,10 @@ int main (int argc, char const *const *argv)
     {
       ip46 z[S6DNS_MAX_SERVERS] ;
       size_t n ;
-      unsigned int k = 0 ;
       if (!*argv[2+i]) continue ;
       if (!ip46_scanlist(z, S6DNS_MAX_SERVERS - j, argv[2 + i], &n))
         strerr_diefu2sys(100, "make an IP address list out of ", argv[2+i]) ;
-      for (; k < n ; k++)
+      for (size_t k = 0 ; k < n ; k++)
       {
         memcpy(s6dns_ip46list_ip(&servers, j + k), z[k].ip, SKALIBS_IP_SIZE) ;
 #ifdef SKALIBS_IPV6_ENABLED
diff --git a/src/clients/s6-dnsqr.c b/src/clients/s6-dnsqr.c
index 290b06a..d8424e5 100644
--- a/src/clients/s6-dnsqr.c
+++ b/src/clients/s6-dnsqr.c
@@ -3,12 +3,14 @@
 #include <string.h>
 #include <stdint.h>
 #include <errno.h>
+
 #include <skalibs/types.h>
 #include <skalibs/strerr.h>
 #include <skalibs/sgetopt.h>
 #include <skalibs/buffer.h>
 #include <skalibs/genwrite.h>
 #include <skalibs/tai.h>
+
 #include <s6-dns/s6dns.h>
 #include <s6-dns/s6dns-analyze.h>
 #include <s6-dns/s6dns-debug.h>
@@ -54,7 +56,9 @@ int main (int argc, char const *const *argv)
     if (debuglevel & 2) { dbh.pre_send = &s6dns_debug_dumpdt_pre_send ; dbh.post_send = &s6dns_debug_dumpdt_post_send ; }
     tain_now_set_stopwatch_g() ;
     tain_add_g(&deadline, &deadline) ;
-    if (!s6dns_init()) strerr_diefu1sys(111, "s6dns_init") ;
+    if (!s6dns_rci_init(&s6dns_rci_here, "/etc/resolv.conf"))
+      strerr_diefu1sys(111, "initialize structures from /etc/resolv.conf") ;
+
     if (!s6dns_resolve_core_r_g(&d, qtype, &s6dns_engine_here, &s6dns_rci_here.servers, &dbh, &deadline))
     {
       char fmt[UINT16_FMT] ;
diff --git a/src/clients/s6-dnsqualify.c b/src/clients/s6-dnsqualify.c
index 38bf3ea..1752389 100644
--- a/src/clients/s6-dnsqualify.c
+++ b/src/clients/s6-dnsqualify.c
@@ -2,8 +2,10 @@
 
 #include <sys/types.h>
 #include <string.h>
+
 #include <skalibs/strerr.h>
 #include <skalibs/buffer.h>
+
 #include <s6-dns/s6dns.h>
 
 #define USAGE "s6-dnsqualify name"
@@ -16,7 +18,10 @@ int main (int argc, char const *const *argv)
   if (argc < 2) dieusage() ;
   if (!s6dns_domain_fromstring(&d, argv[1], strlen(argv[1])))
     strerr_diefu2sys(100, "make a domain name from ", argv[1]) ;
-  if (!s6dns_init()) strerr_diefu1sys(111, "s6dns_init") ;
+
+  if (!s6dns_rci_init(&s6dns_rci_here, "/etc/resolv.conf"))
+    strerr_diefu1sys(111, "initialize structures from /etc/resolv.conf") ;
+
   {
     s6dns_domain_t list[s6dns_rci_here.rulesnum] ;
     unsigned int n = s6dns_qualify(list, &d) ;
diff --git a/src/clients/s6-dnssoa.c b/src/clients/s6-dnssoa.c
index 4df42b4..0ed2ff3 100644
--- a/src/clients/s6-dnssoa.c
+++ b/src/clients/s6-dnssoa.c
@@ -3,6 +3,7 @@
 #include <sys/types.h>
 #include <string.h>
 #include <errno.h>
+
 #include <skalibs/types.h>
 #include <skalibs/sgetopt.h>
 #include <skalibs/strerr.h>
@@ -10,6 +11,7 @@
 #include <skalibs/tai.h>
 #include <skalibs/genalloc.h>
 #include <skalibs/random.h>
+
 #include <s6-dns/s6dns.h>
 
 #define USAGE "s6-dnssoa [ -q ] [ -r ] [ -t timeout ] name"
diff --git a/src/clients/s6-dnssrv.c b/src/clients/s6-dnssrv.c
index b60e3be..c0b9fe3 100644
--- a/src/clients/s6-dnssrv.c
+++ b/src/clients/s6-dnssrv.c
@@ -3,6 +3,7 @@
 #include <sys/types.h>
 #include <string.h>
 #include <errno.h>
+
 #include <skalibs/types.h>
 #include <skalibs/sgetopt.h>
 #include <skalibs/strerr.h>
@@ -10,6 +11,7 @@
 #include <skalibs/tai.h>
 #include <skalibs/genalloc.h>
 #include <skalibs/random.h>
+
 #include <s6-dns/s6dns.h>
 
 #define USAGE "s6-dnssrv [ -q ] [ -r ] [ -t timeout ] service protocol name"
@@ -19,30 +21,36 @@ int main (int argc, char const *const *argv)
 {
   genalloc srvs = GENALLOC_ZERO ; /* array of s6dns_message_rr_srv_t */
   tain deadline ;
-  size_t i = 0 ;
   unsigned int t = 0 ;
   int flagqualify = 0 ;
   int flagunsort = 0 ;
   PROG = "s6-dnssrv" ;
-  for (;;)
+
   {
-    int opt = lgetopt(argc, argv, "qt:") ;
-    if (opt == -1) break ;
-    switch (opt)
+    subgetopt l = SUBGETOPT_ZERO ;
+    for (;;)
     {
-      case 'q' : flagqualify = 1 ; break ;
-      case 'r' : flagunsort = 1 ; break ;
-      case 't' : if (!uint0_scan(subgetopt_here.arg, &t)) dieusage() ; break ;
-      default : dieusage() ;
+      int opt = subgetopt_r(argc, argv, "qrt:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'q' : flagqualify = 1 ; break ;
+        case 'r' : flagunsort = 1 ; break ;
+        case 't' : if (!uint0_scan(l.arg, &t)) dieusage() ; break ;
+        default : dieusage() ;
+      }
     }
+    argc -= l.ind ; argv += l.ind ;
   }
-  argc -= subgetopt_here.ind ; argv += subgetopt_here.ind ;
   if (argc < 3) dieusage() ;
 
   tain_now_set_stopwatch_g() ;
   if (t) tain_from_millisecs(&deadline, t) ; else deadline = tain_infinite_relative ;
   tain_add_g(&deadline, &deadline) ;
-  if (!s6dns_init()) strerr_diefu1sys(111, "s6dns_init") ;
+
+  if (!s6dns_rci_init(&s6dns_rci_here, "/etc/resolv.conf"))
+    strerr_diefu1sys(111, "initialize structures from /etc/resolv.conf") ;
+
   {
     size_t n0 = strlen(argv[0]) ;
     size_t n1 = strlen(argv[1]) ;
@@ -63,7 +71,7 @@ int main (int argc, char const *const *argv)
   }
   if (!genalloc_len(s6dns_message_rr_srv_t, &srvs)) return 1 ;
   if (flagunsort) random_unsort(srvs.s, genalloc_len(s6dns_message_rr_srv_t, &srvs), sizeof(s6dns_message_rr_srv_t)) ;
-  for (i = 0 ; i < genalloc_len(s6dns_message_rr_srv_t, &srvs) ; i++)
+  for (size_t i = 0 ; i < genalloc_len(s6dns_message_rr_srv_t, &srvs) ; i++)
   {
     char buf[S6DNS_FMT_SRV] ;
     size_t len = s6dns_fmt_srv(buf, S6DNS_FMT_SRV, genalloc_s(s6dns_message_rr_srv_t, &srvs) + i) ;
diff --git a/src/clients/s6-dnstxt.c b/src/clients/s6-dnstxt.c
index 2564917..5818ac8 100644
--- a/src/clients/s6-dnstxt.c
+++ b/src/clients/s6-dnstxt.c
@@ -2,6 +2,7 @@
 
 #include <string.h>
 #include <errno.h>
+
 #include <skalibs/types.h>
 #include <skalibs/sgetopt.h>
 #include <skalibs/strerr.h>
@@ -11,6 +12,7 @@
 #include <skalibs/genalloc.h>
 #include <skalibs/skamisc.h>
 #include <skalibs/random.h>
+
 #include <s6-dns/s6dns.h>
 
 #define USAGE "s6-dnstxt [ -q ] [ -r ] [ -t timeout ] name"
@@ -23,24 +25,27 @@ int main (int argc, char const *const *argv)
   genalloc offsets = GENALLOC_ZERO ; /* array of size_t */
   tain deadline ;
   size_t n ;
-  size_t i = 0 ;
   unsigned int t = 0 ;
   int flagqualify = 0 ;
   int flagunsort = 0 ;
   PROG = "s6-dnstxt" ;
-  for (;;)
+
   {
-    int opt = lgetopt(argc, argv, "qrt:") ;
-    if (opt == -1) break ;
-    switch (opt)
+    subgetopt l = SUBGETOPT_ZERO ;
+    for (;;)
     {
-      case 'q' : flagqualify = 1 ; break ;
-      case 'r' : flagunsort = 1 ; break ;
-      case 't' : if (!uint0_scan(subgetopt_here.arg, &t)) dieusage() ; break ;
-      default : dieusage() ;
+      int opt = subgetopt_r(argc, argv, "qrt:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'q' : flagqualify = 1 ; break ;
+        case 'r' : flagunsort = 1 ; break ;
+        case 't' : if (!uint0_scan(l.arg, &t)) dieusage() ; break ;
+        default : dieusage() ;
+      }
     }
+    argc -= l.ind ; argv += l.ind ;
   }
-  argc -= subgetopt_here.ind ; argv += subgetopt_here.ind ;
   if (argc < 1) dieusage() ;
   if (t) tain_from_millisecs(&deadline, t) ; else deadline = tain_infinite_relative ;
 
@@ -56,7 +61,7 @@ int main (int argc, char const *const *argv)
   if (!n) return 1 ;
   {
     size_t printable_offsets[n] ;
-    for (i = 0 ; i < n ; i++)
+    for (size_t i = 0 ; i < n ; i++)
     {
       size_t beg = genalloc_s(size_t, &offsets)[i] ;
       size_t end = (i < n-1 ? genalloc_s(size_t, &offsets)[i+1] : sa.len) - 1 ;
@@ -67,7 +72,7 @@ int main (int argc, char const *const *argv)
     genalloc_free(size_t, &offsets) ;
     stralloc_free(&sa) ;
     if (flagunsort) random_unsort((char *)printable_offsets, n, sizeof(size_t)) ;
-    for (i = 0 ; i < n ; i++)
+    for (size_t i = 0 ; i < n ; i++)
       if ((buffer_puts(buffer_1small, quoted.s + printable_offsets[i]) < 0)
        || (buffer_put(buffer_1small, "\n", 1) < 1))
         strerr_diefu1sys(111, "write to stdout") ;
diff --git a/src/clients/s6-randomip.c b/src/clients/s6-randomip.c
index 6a43794..158440a 100644
--- a/src/clients/s6-randomip.c
+++ b/src/clients/s6-randomip.c
@@ -1,6 +1,6 @@
 /* ISC license. */
 
-#include <sys/types.h>
+#include <stddef.h>
 #include <errno.h>
 
 #include <skalibs/types.h>
@@ -22,22 +22,23 @@ int main (int argc, char const *const *argv)
   size_t what = 0 ;
   int finite = 0 ;
   PROG = "s6-randomip" ;
-  for (;;)
   {
-    int opt = lgetopt(argc, argv, "46n:") ;
-    if (opt == -1) break ;
-    switch (opt)
+    subgetopt l = SUBGETOPT_ZERO ;
+    for (;;)
     {
-      case '4' : what |= 1 ; break ;
-      case '6' : what |= 2 ; break ;
-      case 'n' :
-        if (!uint0_scan(subgetopt_here.arg, &n)) dieusage() ;
-        finite = 1 ;
-        break ;
-      default : dieusage() ;
+      int opt = subgetopt_r(argc, argv, "46n:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case '4' : what |= 1 ; break ;
+        case '6' : what |= 2 ; break ;
+        case 'n' : if (!uint0_scan(l.arg, &n)) dieusage() ; finite = 1 ;
+          break ;
+        default : dieusage() ;
+      }
     }
+    argc -= l.ind ; argv += l.ind ;
   }
-  argc -= subgetopt_here.ind ; argv += subgetopt_here.ind ;
   if (!what) what = 1 ;
   what = 1 << (1 << what) ; 
   for (i = 0 ; !finite || (i < n) ; i++)
@@ -52,7 +53,7 @@ int main (int argc, char const *const *argv)
     random_buf(ip, len) ;
     len = (len == 16) ? ip6_fmt(fmt, ip) : ip4_fmt(fmt, ip) ;
     fmt[len++] = '\n' ;
-    if (buffer_put(buffer_1, fmt, len) < (ssize_t)len)
+    if (buffer_put(buffer_1, fmt, len) < len)
       strerr_diefu1sys(111, "write to stdout") ;
   }
   if (!buffer_flush(buffer_1))
diff --git a/src/clients/s6dns-generic-filter.h b/src/clients/s6dns-generic-filter.h
index 29f758e..9f92dea 100644
--- a/src/clients/s6dns-generic-filter.h
+++ b/src/clients/s6dns-generic-filter.h
@@ -5,7 +5,9 @@
 
 #include <sys/types.h>
 #include <stdint.h>
+
 #include <skalibs/stralloc.h>
+
 #include <s6-dns/s6dns-domain.h>
 
 typedef size_t scan_func (s6dns_domain_t *, char const *) ;
diff --git a/src/clients/s6dns_generic_filter_main.c b/src/clients/s6dns_generic_filter_main.c
index 3e1894d..4c58aae 100644
--- a/src/clients/s6dns_generic_filter_main.c
+++ b/src/clients/s6dns_generic_filter_main.c
@@ -3,6 +3,7 @@
 #include <sys/types.h>
 #include <stdint.h>
 #include <errno.h>
+
 #include <skalibs/error.h>
 #include <skalibs/types.h>
 #include <skalibs/sgetopt.h>
@@ -15,6 +16,7 @@
 #include <skalibs/buffer.h>
 #include <skalibs/bufalloc.h>
 #include <skalibs/skamisc.h>
+
 #include <s6-dns/s6dns-constants.h>
 #include <s6-dns/s6dns-domain.h>
 #include <s6-dns/skadns.h>
diff --git a/src/clients/s6dns_namescanner.c b/src/clients/s6dns_namescanner.c
index 2df6aae..57d3836 100644
--- a/src/clients/s6dns_namescanner.c
+++ b/src/clients/s6dns_namescanner.c
@@ -3,6 +3,7 @@
 #include <sys/types.h>
 #include <limits.h>
 #include <errno.h>
+
 #include <s6-dns/s6dns-domain.h>
 #include "s6dns-generic-filter.h"