IPv6 infrastructure support

Add autoconf rules to detect IPv6 availability and some of the neeeded
support functions. Add stubs for getaddrinfo and inet_ntop.
You can disable IPv6 at compile time with
./configure --without-ipv6

Signed-off-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

5 files changed, 355 insertions, 6 deletions

diff --git a/aclocal.m4 b/aclocal.m4
index 0ea5f1d..c07702c 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -87,6 +87,71 @@ AC_DEFUN(PA_STRUCT_IN_PKTINFO,
 #include <sys/uio.h>
   ])])
 
+
+dnl ------------------------------------------------------------------------
+dnl  PA_STRUCT_SOCKADDR_IN6
+dnl
+dnl Look for definition of struct sockaddr_in6, which at least has an
+dnl sin6_addr member
+dnl
+AH_TEMPLATE([HAVE_STRUCT_SOCKADDR_IN6],
+[Define if struct sockaddr_in6 is defined.])
+
+AC_DEFUN(PA_STRUCT_SOCKADDR_IN6,
+ [AC_CHECK_MEMBER(struct sockaddr_in6.sin6_addr,
+  [
+   AC_DEFINE(HAVE_STRUCT_SOCKADDR_IN6)
+   HAVE_INET6=true;
+  ],
+  [
+   HAVE_INET6=false;
+  ],
+  [
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+  ])])
+
+dnl ------------------------------------------------------------------------
+dnl  PA_STRUCT_ADDRINFO
+dnl
+dnl Look for definition of struct addrinfo, which at least has an
+dnl ai_addr member
+dnl
+AH_TEMPLATE([HAVE_STRUCT_ADDRINFO],
+[Define if struct addrinfo is defined.])
+
+AC_DEFUN(PA_STRUCT_ADDRINFO,
+ [AC_CHECK_MEMBER(struct addrinfo.ai_addr,
+  [AC_DEFINE(HAVE_STRUCT_ADDRINFO)],
+  [],
+  [
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+  ])])
+
+dnl ------------------------------------------------------------------------
+dnl  PA_STRUCT_IN6_PKTINFO
+dnl
+dnl Look for definition of struct in6_pktinfo, which at least has an
+dnl ipi6_addr member
+dnl
+AH_TEMPLATE([HAVE_STRUCT_IN6_PKTINFO],
+[Define if struct in6_pktinfo is defined.])
+
+AC_DEFUN(PA_STRUCT_IN6_PKTINFO,
+ [AC_CHECK_MEMBER(struct in6_pktinfo.ipi6_addr,
+  [AC_DEFINE(HAVE_STRUCT_IN6_PKTINFO)],
+  [],
+  [
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+  ])])
+
 dnl --------------------------------------------------------------------------
 dnl PA_HAVE_TCPWRAPPERS
 dnl
@@ -189,3 +254,27 @@ int main()
 [
  AC_MSG_RESULT(no)
 ])])
+
+dnl --------------------------------------------------------------------------
+dnl  PA_SEARCH_LIBS_AND_ADD
+dnl
+dnl  PA_SEARCH_LIBS_AND_ADD(function, libraries [,function to add])
+dnl --------------------------------------------------------------------------
+
+AC_DEFUN(PA_SEARCH_LIBS_AND_ADD,
+ [
+  AH_TEMPLATE(AS_TR_CPP(HAVE_$1), [Define if $1 function was found])
+  AC_SEARCH_LIBS($1, $2,
+   [
+    AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_$1))
+    pa_add_$1=false;
+   ],
+   [
+    XTRA=true;
+    if test $# -eq 3; then
+      AC_LIBOBJ($3)
+    else
+      AC_LIBOBJ($1)
+    fi
+    pa_add_$1=true;
+   ])])
diff --git a/config.h b/config.h
index ed1e39a..38be517 100644
--- a/config.h
+++ b/config.h
@@ -106,6 +106,9 @@
 #endif
 #endif
 #endif
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
 
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
@@ -301,6 +304,49 @@ int dup2(int, int);
 int daemon(int, int);
 #endif
 
+#ifndef HAVE_GETADDRINFO
+#ifndef HAVE_STRUCT_ADDRINFO
+struct addrinfo {
+    int     ai_flags;
+    int     ai_family;
+    int     ai_socktype;
+    int     ai_protocol;
+    size_t  ai_addrlen;
+    struct sockaddr *ai_addr;
+    char    *ai_canonname;
+    struct addrinfo *ai_next;
+};
+#endif
+int getaddrinfo(const char *, const char *, const struct addrinfo *,
+                struct addrinfo **);
+void freeaddrinfo(struct addrinfo *);
+const char *gai_strerror(int);
+
+#ifndef AI_CANONNAME
+#define AI_CANONNAME    0x0002  /* Request for canonical name.  */
+#endif
+
+#ifndef EAI_NONAME
+#define EAI_NONAME      -2    /* NAME or SERVICE is unknown.  */
+#endif
+#ifndef EAI_ADDRFAMILY
+#define EAI_ADDRFAMILY -9    /* Address family for NAME not supported.  */
+#endif
+#ifndef EAI_MEMORY
+#define EAI_MEMORY      -10   /* Memory allocation failure.  */
+#endif
+#ifndef EAI_SYSTEM
+#define EAI_SYSTEM      -11   /* System error returned in rrno'.  */
+#endif
+#endif
+
+#ifndef HAVE_INET_NTOP
+const char *inet_ntop(int, const void *, char *, socklen_t);
+#ifndef INET6_ADDRSTRLEN
+#define INET6_ADDRSTRLEN 48
+#endif
+#endif
+
 /* tftp-hpa version and configuration strings */
 
 #include "version.h"
diff --git a/configure.in b/configure.in
index ddd11da..91fd889 100644
--- a/configure.in
+++ b/configure.in
@@ -52,6 +52,7 @@ AC_CHECK_HEADERS(sys/stat.h)
 AC_CHECK_HEADERS(sys/time.h)
 AC_CHECK_HEADERS(sys/types.h)
 AC_CHECK_HEADERS(arpa/inet.h)
+AC_CHECK_HEADERS(netdb.h)
 AC_HEADER_TIME
 dnl This is needed on some versions of FreeBSD...
 AC_CHECK_HEADERS(machine/param.h)
@@ -118,9 +119,6 @@ AC_CHECK_TYPES(socklen_t,,,
 ])
 
 AC_SEARCH_LIBS(socket, [socket ws2_32 wsock32], , [AC_MSG_ERROR(socket library not found)])
-AC_SEARCH_LIBS(gethostbyname, [nsl resolv], , [AC_MSG_ERROR(gethostbyname not found)])
-AC_SEARCH_LIBS(inet_aton, [nsl resolv], , [AC_MSG_ERROR(inet_aton not found)])
-AC_SEARCH_LIBS(herror, [nsl resolv], , [AC_MSG_ERROR(herror not found)])
 
 AC_CHECK_FUNCS(fcntl)
 AC_CHECK_FUNCS(setsid)
@@ -137,6 +135,7 @@ AC_CHECK_FUNCS(strtoull)
 
 PA_MSGHDR_MSG_CONTROL
 PA_STRUCT_IN_PKTINFO
+PA_STRUCT_ADDRINFO
 
 PA_HEADER_DEFINES(fcntl.h, int, O_NONBLOCK)
 PA_HEADER_DEFINES(fcntl.h, int, O_BINARY)
@@ -153,9 +152,30 @@ SRCROOT=`cd $srcdir && pwd`
 OBJROOT=`pwd`
 
 XTRA=false
-AC_SEARCH_LIBS(xmalloc, iberty, , [XTRA=true; AC_LIBOBJ(xmalloc)])
-AC_SEARCH_LIBS(xstrdup, iberty, , [XTRA=true; AC_LIBOBJ(xstrdup)])
-AC_SEARCH_LIBS(bsd_signal, bsd, , [XTRA=true; AC_LIBOBJ(bsdsignal)])
+PA_SEARCH_LIBS_AND_ADD(xmalloc, iberty)
+PA_SEARCH_LIBS_AND_ADD(xstrdup, iberty)
+PA_SEARCH_LIBS_AND_ADD(bsd_signal, bsd, bsdsignal)
+PA_SEARCH_LIBS_AND_ADD(getaddrinfo, [nsl resolv])
+if $pa_add_getaddrinfo
+then
+    AC_SEARCH_LIBS(gethostbyname, [nsl resolv],
+      [AC_SEARCH_LIBS(herror, [nsl resolv], ,
+	 [AC_MSG_ERROR(herror not found)])],
+      [AC_MSG_ERROR(gethostbyname not found)])
+else
+    AC_SEARCH_LIBS(freeaddrinfo, [nsl resolv], ,
+      [AC_MSG_ERROR(getaddrinfo but not freeaddrinfo found)])
+    AC_SEARCH_LIBS(gai_strerror, [nsl resolv], ,
+      [AC_MSG_ERROR(getaddrinfo but not gai_strerror found)])
+fi
+
+PA_SEARCH_LIBS_AND_ADD(inet_ntop, [nsl resolv])
+if $pa_add_inet_ntop
+then
+    AC_SEARCH_LIBS(inet_ntoa, [nsl resolv], ,
+      [AC_MSG_ERROR(inet_ntoa not found)])
+fi
+
 AC_CHECK_FUNCS(daemon, , [XTRA=true; AC_LIBOBJ(daemon)])
 AC_CHECK_FUNCS(dup2, , [XTRA=true; AC_LIBOBJ(dup2)])
 if $XTRA
@@ -226,6 +246,27 @@ PA_WITH_BOOL(readline, 1,
 TFTP_LIBS="$LIBS $XTRALIBS"
 LIBS="$common_libs"
 
+dnl
+dnl   Check for IPV6 and disable-ipv6
+dnl
+PA_STRUCT_SOCKADDR_IN6
+AC_MSG_CHECKING([for IPv6 support])
+PA_WITH_BOOL(ipv6, 1,
+[  --without-ipv6      disable the support for IPv6],
+[
+    if  $HAVE_INET6
+    then
+	AC_MSG_RESULT(yes)
+        AC_DEFINE(HAVE_IPV6, 1, [Define if IPv6 support is enabled.])
+        PA_STRUCT_IN6_PKTINFO
+    else
+	AC_MSG_RESULT(no)
+        AC_MSG_WARN([*** we do not have required IPv6 structs - IPv6 will be disabled])
+    fi
+],
+[AC_MSG_RESULT(disabled)])
+
+
 AC_SUBST(SRCROOT)
 AC_SUBST(OBJROOT)
 
diff --git a/lib/getaddrinfo.c b/lib/getaddrinfo.c
new file mode 100644
index 0000000..ef7c9ae
--- /dev/null
+++ b/lib/getaddrinfo.c
@@ -0,0 +1,121 @@
+/*
+ * getaddrinfo.c
+ *
+ * Simple version of getaddrinfo()
+ *
+ */
+
+#include "config.h"
+
+extern int errno;
+extern int h_errno;
+
+void freeaddrinfo(struct addrinfo *res)
+{
+    if (!res)
+        return;
+    if (res->ai_next)
+        freeaddrinfo(res->ai_next);
+    if (res->ai_addr)
+        free(res->ai_addr);
+    if (res->ai_canonname)
+        free(res->ai_canonname);
+    free(res);
+}
+
+int getaddrinfo(const char *node, const char *service, const struct addrinfo *hints,
+                struct addrinfo **res)
+{
+    struct hostent  *host;
+    struct sockaddr *sa;
+    int err, size = 0;
+
+    if ((!node) || (!res)) {
+        errno = EINVAL;
+        return EAI_SYSTEM;
+    }
+    *res = NULL;
+    /* we do not support service in this version */
+    if (service) {
+        errno = EINVAL;
+        return EAI_SYSTEM;
+    }
+    host = gethostbyname(node);
+    if (!host)
+        return EAI_NONAME;
+    if (hints) {
+        if (hints->ai_family != AF_UNSPEC) {
+            if (hints->ai_family != host->h_addrtype)
+                return EAI_ADDRFAMILY;
+        }
+    }
+    *res =  malloc(sizeof(struct addrinfo));
+    if (!*res) {
+        return EAI_MEMORY;
+    }
+    memset(*res, 0, sizeof(struct addrinfo));
+    (*res)->ai_family = host->h_addrtype;
+    if (host->h_length) {
+        if (host->h_addrtype == AF_INET)
+            size = sizeof(struct sockaddr_in);
+#ifdef HAVE_IPV6
+        else if (host->h_addrtype == AF_INET6)
+            size = sizeof(struct sockaddr_in6);
+#endif
+        else {
+            free(*res);
+            *res = NULL;
+            return EAI_ADDRFAMILY;
+        }
+        sa = malloc(size);
+        if (!sa) {
+            free(*res);
+            *res = NULL;
+            return EAI_MEMORY;
+        }
+        memset(sa, 0, size);
+        (*res)->ai_addr = sa;
+        (*res)->ai_addrlen = size;
+        sa->sa_family = host->h_addrtype;
+        if (host->h_addrtype == AF_INET)
+            memcpy(&((struct sockaddr_in *)sa)->sin_addr, host->h_addr, host->h_length);
+#ifdef HAVE_IPV6
+        else
+            memcpy(&((struct sockaddr_in6 *)sa)->sin6_addr, host->h_addr, host->h_length);
+#endif
+    }
+    if (host->h_name)
+       (*res)->ai_canonname = strdup(host->h_name);
+
+    /* we only handle the first address entry and do not build a list now */
+    return 0;
+}
+
+
+
+const char *gai_strerror(int errcode)
+{
+    const char *s = NULL;
+
+    switch(errcode) {
+    case 0:
+        s = "no error";
+        break;
+    case EAI_MEMORY:
+        s = "no memory";
+        break;
+    case EAI_SYSTEM:
+        s = strerror(errno);
+        break;
+    case EAI_NONAME:
+        s = hstrerror(h_errno);
+        break;
+    case EAI_ADDRFAMILY:
+        s = "address does not match address family";
+        break;
+    default:
+        s = "unknown error code";
+        break;
+    }
+    return s;
+}
diff --git a/lib/inet_ntop.c b/lib/inet_ntop.c
new file mode 100644
index 0000000..fe8e560
--- /dev/null
+++ b/lib/inet_ntop.c
@@ -0,0 +1,52 @@
+/*
+ * inet_ntop.c
+ *
+ * Simple version of inet_ntop()
+ *
+ */
+
+#include "config.h"
+
+extern int errno;
+
+const char *inet_ntop(int af, const void *src,
+                      char *dst, socklen_t cnt)
+{
+    char *p;
+
+    switch(af) {
+    case AF_INET:
+        p = inet_ntoa(*((struct in_addr *)src));
+        if (p) {
+            if (cnt <= strlen(p)) {
+                errno = ENOSPC;
+                dst = NULL;
+            } else
+                strcpy(dst, p);
+        } else
+            dst = NULL;
+        break;
+#ifdef HAVE_IPV6
+    case AF_INET6:
+        if (cnt < 40) {
+            errno = ENOSPC;
+            dst = NULL;
+        } else {
+            struct in6_addr *a = src;
+            int i;
+
+            p = (char *)dst;
+            /* we do not compress :0: to  :: */
+            for (i = 0; i < 8; i++)
+                p += sprintf(p, "%x:", ntohs(a->s6_addr16[i]));
+            p--;
+            *p = 0;
+        }
+        break;
+#endif
+    default:
+        errno = EAFNOSUPPORT;
+        dst = NULL;
+    }
+    return dst;
+}