rely on standard POSIX headers to fix globs of warnings

--- a/tcprulescheck.c
+++ b/tcprulescheck.c
@@ -1,3 +1,5 @@
+#include <unistd.h>
+
 #include "byte.h"
 #include "buffer.h"
 #include "strerr.h"
--- a/buffer.c
+++ b/buffer.c
@@ -1,6 +1,6 @@
 #include "buffer.h"
 
-void buffer_init(buffer *s,int (*op)(),int fd,char *buf,unsigned int len)
+void buffer_init(buffer *s,ssize_t (*op)(),int fd,char *buf,unsigned int len)
 {
   s->x = buf;
   s->fd = fd;
--- a/buffer.h
+++ b/buffer.h
@@ -1,6 +1,8 @@
 #ifndef BUFFER_H
 #define BUFFER_H
 
+#include <sys/types.h>
+
 typedef struct buffer {
   char *x;
   unsigned int p;
@@ -13,7 +15,7 @@ typedef struct buffer {
 #define BUFFER_INSIZE 8192
 #define BUFFER_OUTSIZE 8192
 
-extern void buffer_init(buffer *,int (*)(),int,char *,unsigned int);
+extern void buffer_init(buffer *,ssize_t (*)(),int,char *,unsigned int);
 
 extern int buffer_flush(buffer *);
 extern int buffer_put(buffer *,char *,unsigned int);
--- a/exit.h
+++ b/exit.h
@@ -1,6 +1,6 @@
 #ifndef EXIT_H
 #define EXIT_H
 
-extern void _exit();
+#include <unistd.h>
 
 #endif
--- a/install.c
+++ b/install.c
@@ -1,3 +1,4 @@
+#include <sys/stat.h>
 #include "buffer.h"
 #include "strerr.h"
 #include "error.h"
--- a/readwrite.h
+++ b/readwrite.h
@@ -1,7 +1,6 @@
 #ifndef READWRITE_H
 #define READWRITE_H
 
-extern int read();
-extern int write();
+#include <unistd.h>
 
 #endif

--- a/auto-str.c
+++ b/auto-str.c
@@ -5,6 +5,7 @@
 char bspace[256];
 buffer b = BUFFER_INIT(write,1,bspace,sizeof bspace);
 
+#define puts _puts
 void puts(char *s)
 {
   if (buffer_puts(&b,s) == -1) _exit(111);
--- a/buffer.h
+++ b/buffer.h
@@ -8,7 +8,7 @@ typedef struct buffer {
   unsigned int p;
   unsigned int n;
   int fd;
-  int (*op)();
+  ssize_t (*op)();
 } buffer;
 
 #define BUFFER_INIT(op,fd,buf,len) { (buf), 0, (len), (fd), (op) }
--- a/fd_copy.c
+++ b/fd_copy.c
@@ -1,4 +1,5 @@
 #include <fcntl.h>
+#include <unistd.h>
 #include "fd.h"
 
 int fd_copy(int to,int from)
--- a/fd_move.c
+++ b/fd_move.c
@@ -1,3 +1,4 @@
+#include <unistd.h>
 #include "fd.h"
 
 int fd_move(int to,int from)
--- a/socket_tcp.c
+++ b/socket_tcp.c
@@ -1,3 +1,4 @@
+#include <unistd.h>
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/socket.h>
--- a/chkshsgr.c
+++ b/chkshsgr.c
@@ -1,8 +1,9 @@
+#include <grp.h>
 #include "exit.h"
 
 main()
 {
-  short x[4];
+  gid_t x[4];
 
   x[0] = x[1] = 0;
   if (getgroups(1,x) == 0) if (setgroups(1,x) == -1) _exit(1);
--- a/prot.c
+++ b/prot.c
@@ -1,10 +1,10 @@
 #include "hasshsgr.h"
 #include "prot.h"
 
-int prot_gid(int gid)
+int prot_gid(gid_t gid)
 {
 #ifdef HASSHORTSETGROUPS
-  short x[2];
+  gid_t x[2];
   x[0] = gid; x[1] = 73; /* catch errors */
   if (setgroups(1,x) == -1) return -1;
 #else
@@ -13,7 +13,7 @@ int prot_gid(int gid)
   return setgid(gid); /* _should_ be redundant, but on some systems it isn't */
 }
 
-int prot_uid(int uid)
+int prot_uid(uid_t uid)
 {
   return setuid(uid);
 }
--- a/prot.h
+++ b/prot.h
@@ -1,7 +1,10 @@
 #ifndef PROT_H
 #define PROT_H
 
-extern int prot_gid(int);
-extern int prot_uid(int);
+#include <unistd.h>
+#include <grp.h>
+
+extern int prot_gid(gid_t);
+extern int prot_uid(uid_t);
 
 #endif
--- a/fixcrio.c
+++ b/fixcrio.c
@@ -6,6 +6,7 @@
 #include "exit.h"
 #include "iopause.h"
 #include "pathexec.h"
+#include "fd.h"
 
 #define FATAL "fixcrio: fatal: "
 
--- a/hier.c
+++ b/hier.c
@@ -1,5 +1,9 @@
 #include "auto_home.h"
 
+extern void h(char *, int, int, int);
+extern void d(char *, char *, int, int, int);
+extern void c(char *, char *, char *, int, int, int);
+
 void hier()
 {
   h(auto_home,-1,-1,02755);
--- a/mconnect-io.c
+++ b/mconnect-io.c
@@ -1,3 +1,4 @@
+#include <signal.h>
 #include "sig.h"
 #include "wait.h"
 #include "fork.h"
@@ -12,7 +13,7 @@ buffer bout;
 char inbuf[512];
 buffer bin;
 
-int myread(int fd,char *buf,int len)
+ssize_t myread(int fd,char *buf,int len)
 {
   buffer_flush(&bout);
   return read(fd,buf,len);
--- a/tcprules.c
+++ b/tcprules.c
@@ -1,3 +1,4 @@
+#include <stdio.h>
 #include "strerr.h"
 #include "stralloc.h"
 #include "getln.h"
@@ -6,6 +7,8 @@
 #include "fmt.h"
 #include "byte.h"
 #include "cdb_make.h"
+#include "open.h"
+#include "scan.h"
 
 #define FATAL "tcprules: fatal: "
 
--- a/pathexec_run.c
+++ b/pathexec_run.c
@@ -1,3 +1,4 @@
+#include <unistd.h>
 #include "error.h"
 #include "stralloc.h"
 #include "str.h"
--- a/recordio.c
+++ b/recordio.c
@@ -8,6 +8,7 @@
 #include "fmt.h"
 #include "iopause.h"
 #include "pathexec.h"
+#include "fd.h"
 
 #define FATAL "recordio: fatal: "
 
--- a/seek_set.c
+++ b/seek_set.c
@@ -1,7 +1,6 @@
+#include <unistd.h>
 #include <sys/types.h>
 #include "seek.h"
 
-#define SET 0 /* sigh */
-
 int seek_set(int fd,seek_pos pos)
-{ if (lseek(fd,(off_t) pos,SET) == -1) return -1; return 0; }
+{ if (lseek(fd,(off_t) pos,SEEK_SET) == -1) return -1; return 0; }
--- a/socket_udp.c
+++ b/socket_udp.c
@@ -2,6 +2,7 @@
 #include <sys/param.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
+#include <unistd.h>
 #include "ndelay.h"
 #include "socket.h"
 
--- a/tcprulescheck.c
+++ b/tcprulescheck.c
@@ -5,6 +5,7 @@
 #include "strerr.h"
 #include "env.h"
 #include "rules.h"
+#include "open.h"
 
 void found(char *data,unsigned int datalen)
 {

the prototypes are added near the top to avoid conflicts w/ipv6 patch

--- a/socket.h
+++ b/socket.h
@@ -3,6 +3,9 @@
 #ifndef SOCKET_H
 #define SOCKET_H
 
+extern int socket_tcpnodelay(int);
+extern int socket_ipoptionskill(int);
+
 #include "uint16.h"
 
 extern int socket_tcp(void);
--- a/remoteinfo.c
+++ b/remoteinfo.c
@@ -1,3 +1,4 @@
+#include <unistd.h>
 #include "fmt.h"
 #include "buffer.h"
 #include "socket.h"
@@ -5,11 +6,12 @@
 #include "iopause.h"
 #include "timeoutconn.h"
 #include "remoteinfo.h"
+#include "readwrite.h"
 
 static struct taia now;
 static struct taia deadline;
 
-static int mywrite(int fd,char *buf,int len)
+static ssize_t mywrite(int fd,char *buf,int len)
 {
   iopause_fd x;
 
@@ -27,7 +29,7 @@ static int mywrite(int fd,char *buf,int len)
   return write(fd,buf,len);
 }
 
-static int myread(int fd,char *buf,int len)
+static ssize_t myread(int fd,char *buf,int len)
 {
   iopause_fd x;
 
--- a/alloc.c
+++ b/alloc.c
@@ -1,7 +1,5 @@
 #include "alloc.h"
 #include "error.h"
-extern char *malloc();
-extern void free();
 
 #define ALIGNMENT 16 /* XXX: assuming that this alignment is enough */
 #define SPACE 2048 /* must be multiple of ALIGNMENT */
--- a/alloc.h
+++ b/alloc.h
@@ -1,8 +1,10 @@
 #ifndef ALLOC_H
 #define ALLOC_H
 
-extern /*@null@*//*@out@*/char *alloc();
-extern void alloc_free();
+#include <stdlib.h>
+
+extern /*@null@*//*@out@*/char *alloc(unsigned int);
+extern void alloc_free(char *);
 extern int alloc_re();
 
 #endif
--- a/buffer_0.c
+++ b/buffer_0.c
@@ -1,7 +1,7 @@
 #include "readwrite.h"
 #include "buffer.h"
 
-int buffer_0_read(fd,buf,len) int fd; char *buf; int len;
+ssize_t buffer_0_read(fd,buf,len) int fd; char *buf; int len;
 {
   if (buffer_flush(buffer_1) == -1) return -1;
   return read(fd,buf,len);
--- a/buffer_get.c
+++ b/buffer_get.c
@@ -2,7 +2,7 @@
 #include "byte.h"
 #include "error.h"
 
-static int oneread(int (*op)(),int fd,char *buf,unsigned int len)
+static int oneread(ssize_t (*op)(),int fd,char *buf,unsigned int len)
 {
   int r;
 
--- a/buffer_put.c
+++ b/buffer_put.c
@@ -3,7 +3,7 @@
 #include "byte.h"
 #include "error.h"
 
-static int allwrite(int (*op)(),int fd,char *buf,unsigned int len)
+static int allwrite(ssize_t (*op)(),int fd,char *buf,unsigned int len)
 {
   int w;
 
--- a/case.h
+++ b/case.h
@@ -4,7 +4,7 @@
 extern void case_lowers(char *);
 extern void case_lowerb(char *,unsigned int);
 extern int case_diffs(char *,char *);
-extern int case_diffb(char *,unsigned int,char *);
+extern int case_diffb(const char *,unsigned int,const char *);
 extern int case_starts(char *,char *);
 extern int case_startb(char *,unsigned int,char *);
 
--- a/case_diffb.c
+++ b/case_diffb.c
@@ -1,6 +1,6 @@
 #include "case.h"
 
-int case_diffb(register char *s,register unsigned int len,register char *t)
+int case_diffb(register const char *s,register unsigned int len,const register char *t)
 {
   register unsigned char x;
   register unsigned char y;
--- a/open.h
+++ b/open.h
@@ -1,10 +1,10 @@
 #ifndef OPEN_H
 #define OPEN_H
 
-extern int open_read(char *);
-extern int open_excl(char *);
-extern int open_append(char *);
-extern int open_trunc(char *);
-extern int open_write(char *);
+extern int open_read(const char *);
+extern int open_excl(const char *);
+extern int open_append(const char *);
+extern int open_trunc(const char *);
+extern int open_write(const char *);
 
 #endif
--- a/open_read.c
+++ b/open_read.c
@@ -2,5 +2,5 @@
 #include <fcntl.h>
 #include "open.h"
 
-int open_read(char *fn)
+int open_read(const char *fn)
 { return open(fn,O_RDONLY | O_NDELAY); }
--- a/open_trunc.c
+++ b/open_trunc.c
@@ -2,5 +2,5 @@
 #include <fcntl.h>
 #include "open.h"
 
-int open_trunc(char *fn)
+int open_trunc(const char *fn)
 { return open(fn,O_WRONLY | O_NDELAY | O_TRUNC | O_CREAT,0644); }
--- a/open_write.c
+++ b/open_write.c
@@ -2,5 +2,5 @@
 #include <fcntl.h>
 #include "open.h"
 
-int open_write(char *fn)
+int open_write(const char *fn)
 { return open(fn,O_WRONLY | O_NDELAY); }
--- a/openreadclose.c
+++ b/openreadclose.c
@@ -3,7 +3,7 @@
 #include "readclose.h"
 #include "openreadclose.h"
 
-int openreadclose(char *fn,stralloc *sa,unsigned int bufsize)
+int openreadclose(const char *fn,stralloc *sa,unsigned int bufsize)
 {
   int fd;
   fd = open_read(fn);
--- a/openreadclose.h
+++ b/openreadclose.h
@@ -3,6 +3,6 @@
 
 #include "stralloc.h"
 
-extern int openreadclose(char *,stralloc *,unsigned int);
+extern int openreadclose(const char *,stralloc *,unsigned int);
 
 #endif
--- a/stralloc.h
+++ b/stralloc.h
@@ -7,7 +7,7 @@ GEN_ALLOC_typedef(stralloc,char,s,len,a)
 
 extern int stralloc_ready(stralloc *,unsigned int);
 extern int stralloc_readyplus(stralloc *,unsigned int);
-extern int stralloc_copy(stralloc *,stralloc *);
+extern int stralloc_copy(stralloc *,const stralloc *);
 extern int stralloc_cat(stralloc *,stralloc *);
 extern int stralloc_copys(stralloc *,const char *);
 extern int stralloc_cats(stralloc *,const char *);
--- a/stralloc_copy.c
+++ b/stralloc_copy.c
@@ -1,7 +1,7 @@
 #include "byte.h"
 #include "stralloc.h"
 
-int stralloc_copy(stralloc *sato,stralloc *safrom)
+int stralloc_copy(stralloc *sato,const stralloc *safrom)
 {
   return stralloc_copyb(sato,safrom->s,safrom->len);
 }
--- a/taia.h
+++ b/taia.h
@@ -19,7 +19,7 @@ extern double taia_frac(struct taia *);
 extern void taia_add(struct taia *,struct taia *,struct taia *);
 extern void taia_sub(struct taia *,struct taia *,struct taia *);
 extern void taia_half(struct taia *,struct taia *);
-extern int taia_less(struct taia *,struct taia *);
+extern int taia_less(const struct taia *,const struct taia *);
 
 #define TAIA_PACK 16
 extern void taia_pack(char *,struct taia *);
--- a/taia_less.c
+++ b/taia_less.c
@@ -2,7 +2,7 @@
 
 /* XXX: breaks tai encapsulation */
 
-int taia_less(struct taia *t,struct taia *u)
+int taia_less(const struct taia *t,const struct taia *u)
 {
   if (t->sec.x < u->sec.x) return 1;
   if (t->sec.x > u->sec.x) return 0;
--- a/uint32.h1
+++ b/uint32.h1
@@ -5,7 +5,7 @@ typedef unsigned int uint32;
 
 extern void uint32_pack(char *,uint32);
 extern void uint32_pack_big(char *,uint32);
-extern void uint32_unpack(char *,uint32 *);
-extern void uint32_unpack_big(char *,uint32 *);
+extern void uint32_unpack(const char *,uint32 *);
+extern void uint32_unpack_big(const char *,uint32 *);
 
 #endif
--- a/uint32.h2
+++ b/uint32.h2
@@ -5,7 +5,7 @@ typedef unsigned long uint32;
 
 extern void uint32_pack(char *,uint32);
 extern void uint32_pack_big(char *,uint32);
-extern void uint32_unpack(char *,uint32 *);
-extern void uint32_unpack_big(char *,uint32 *);
+extern void uint32_unpack(const char *,uint32 *);
+extern void uint32_unpack_big(const char *,uint32 *);
 
 #endif
--- a/uint32_unpack.c
+++ b/uint32_unpack.c
@@ -1,6 +1,6 @@
 #include "uint32.h"
 
-void uint32_unpack(char s[4],uint32 *u)
+void uint32_unpack(const char s[4],uint32 *u)
 {
   uint32 result;
 
@@ -15,7 +15,7 @@ void uint32_unpack(char s[4],uint32 *u)
   *u = result;
 }
 
-void uint32_unpack_big(char s[4],uint32 *u)
+void uint32_unpack_big(const char s[4],uint32 *u)
 {
   uint32 result;