Update to rra-c-util 3.9

* Add notices in each file copied from rra-c-util.
* Prefer gssapi/gssapi.h to gssapi.h.
* Include strings.h if it exists for strncasecmp on some platforms.
* getaddrinfo replacement now portable to systems with bad netdb.h.
* Avoid krb5-config if --with-gssapi-{include,lib} are given.
* Add Windows implementation of fdflag_nonblocking.
* The network_connect utility functions now take an optional timeout.
* Use typedef instead of #define for socklen_t and sig_atomic_t.
* Stop providing or using INADDR_LOOPBACK for portability reasons.

15 files changed, 212 insertions, 62 deletions

diff --git a/util/concat.c b/util/concat.c
index 0525ddb..fb4afa8 100644
--- a/util/concat.c
+++ b/util/concat.c
@@ -18,6 +18,9 @@
  * together and returned.  This is useful for building file names where names
  * that aren't fully qualified are qualified with some particular directory.
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Written by Russ Allbery <rra@stanford.edu>
  *
  * The authors hereby relinquish any claim to any copyright that they may have
diff --git a/util/concat.h b/util/concat.h
index 9712d70..960f242 100644
--- a/util/concat.h
+++ b/util/concat.h
@@ -1,6 +1,9 @@
 /*
  * Prototypes for string concatenation with dynamic memory allocation.
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Written by Russ Allbery <rra@stanford.edu>
  *
  * The authors hereby relinquish any claim to any copyright that they may have
diff --git a/util/fdflag.c b/util/fdflag.c
index bf3125e..1be200c 100644
--- a/util/fdflag.c
+++ b/util/fdflag.c
@@ -4,7 +4,10 @@
  * Simple functions (wrappers around fcntl) to set or clear file descriptor
  * flags like close-on-exec or nonblocking I/O.
  *
- * Copyright 2008
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
+ * Copyright 2008, 2011
  *     The Board of Trustees of the Leland Stanford Junior University
  * Copyright (c) 2004, 2005, 2006
  *     by Internet Systems Consortium, Inc. ("ISC")
@@ -30,16 +33,21 @@
 #include <config.h>
 #include <portable/system.h>
 
-#include <errno.h>
-#include <fcntl.h>
-#ifndef O_NONBLOCK
-# include <sys/ioctl.h>
-# if HAVE_SYS_FILIO_H
-#  include <sys/filio.h>
+#ifdef _WIN32
+# include <winsock2.h>
+#else
+# include <errno.h>
+# include <fcntl.h>
+# ifndef O_NONBLOCK
+#  include <sys/ioctl.h>
+#  if HAVE_SYS_FILIO_H
+#   include <sys/filio.h>
+#  endif
 # endif
 #endif
 
 #include <util/fdflag.h>
+#include <util/macros.h>
 
 
 /*
@@ -49,7 +57,17 @@
  * One is supposed to retrieve the flags, add FD_CLOEXEC, and then set them,
  * although I've never seen a system with any flags other than close-on-exec.
  * Do it right anyway; it's not that expensive.
-*/
+ *
+ * Stub this out on Windows, where it's not supported (at least currently by
+ * this utility library).
+ */
+#ifdef _WIN32
+bool
+fdflag_close_exec(int fd UNUSED, bool flag UNUSED)
+{
+    return false;
+}
+#else
 bool
 fdflag_close_exec(int fd, bool flag)
 {
@@ -61,17 +79,23 @@ fdflag_close_exec(int fd, bool flag)
     mode = flag ? (oflag | FD_CLOEXEC) : (oflag & ~FD_CLOEXEC);
     return (fcntl(fd, F_SETFD, mode) == 0);
 }
+#endif
 
 
 /*
  * Set a file descriptor to nonblocking (or clear the nonblocking flag if flag
  * is false), returning true on success and false on failure.
  *
- * Always use O_NONBLOCK; O_NDELAY is not the same thing historically.  The
- * semantics of O_NDELAY are that if the read would block, it returns 0
- * instead.  This is indistinguishable from an end of file condition.  POSIX
- * added O_NONBLOCK, which requires read to return -1 and set errno to EAGAIN,
- * which is what we want.
+ * For Windows, be aware that this will only work for sockets.  For UNIX, you
+ * can pass a non-socket in and it will do the right thing, since UNIX doesn't
+ * distinguish, but Windows will not allow that.  Thankfully, there's rarely
+ * any need to set non-sockets non-blocking.
+ *
+ * For UNIX, always use O_NONBLOCK; O_NDELAY is not the same thing
+ * historically.  The semantics of O_NDELAY are that if the read would block,
+ * it returns 0 instead.  This is indistinguishable from an end of file
+ * condition.  POSIX added O_NONBLOCK, which requires read to return -1 and
+ * set errno to EAGAIN, which is what we want.
  *
  * FNDELAY (4.3BSD) originally did the correct thing, although it has a
  * different incompatibility (affecting all users of a socket rather than just
@@ -93,9 +117,18 @@ fdflag_close_exec(int fd, bool flag)
  * O_NONBLOCK).  Accordingly, we currently unconditionally use O_NONBLOCK.  If
  * this causes too many problems, an autoconf test may be required.
  */
-#ifdef O_NONBLOCK
+#if defined(_WIN32)
+bool
+fdflag_nonblocking(socket_type fd, bool flag)
+{
+    u_long mode;
+
+    mode = flag ? 1 : 0;
+    return (ioctlsocket(fd, FIONBIO, &mode) == 0);
+}
+#elif defined(O_NONBLOCK)
 bool
-fdflag_nonblocking(int fd, bool flag)
+fdflag_nonblocking(socket_type fd, bool flag)
 {
     int mode;
 
@@ -106,8 +139,8 @@ fdflag_nonblocking(int fd, bool flag)
     return (fcntl(fd, F_SETFL, mode) == 0);
 }
 #else /* !O_NONBLOCK */
-int
-nonblocking(int fd, bool flag)
+bool
+fdflag_nonblocking(socket_type fd, bool flag)
 {
     int state;
 
diff --git a/util/fdflag.h b/util/fdflag.h
index 6b8af60..bed45da 100644
--- a/util/fdflag.h
+++ b/util/fdflag.h
@@ -1,7 +1,10 @@
 /*
  * Prototypes for setting or clearing file descriptor flags.
  *
- * Copyright 2008, 2010
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
+ * Copyright 2008, 2010, 2011
  *     The Board of Trustees of the Leland Stanford Junior University
  * Copyright (c) 2004, 2005, 2006
  *     by Internet Systems Consortium, Inc. ("ISC")
@@ -30,15 +33,22 @@
 #include <config.h>
 #include <portable/macros.h>
 #include <portable/stdbool.h>
+#include <portable/socket.h>
 
 BEGIN_DECLS
 
 /* Default to a hidden visibility for all util functions. */
 #pragma GCC visibility push(hidden)
 
-/* Set a file descriptor close-on-exec or nonblocking. */
+/*
+ * Set a file descriptor close-on-exec or nonblocking.  fdflag_close_exec is
+ * not supported on Windows and will always return false.  fdflag_nonblocking
+ * is defined to take a socket_type so that it can be supported on Windows.
+ * On UNIX systems, you can safely pass in a non-socket file descriptor, but
+ * be aware that this will fail to compile on Windows.
+ */
 bool fdflag_close_exec(int fd, bool flag);
-bool fdflag_nonblocking(int fd, bool flag);
+bool fdflag_nonblocking(socket_type fd, bool flag);
 
 /* Undo default visibility change. */
 #pragma GCC visibility pop
diff --git a/util/macros.h b/util/macros.h
index 084a5a2..54faee5 100644
--- a/util/macros.h
+++ b/util/macros.h
@@ -1,6 +1,9 @@
 /*
  * Some standard helpful macros.
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Written by Russ Allbery <rra@stanford.edu>
  *
  * The authors hereby relinquish any claim to any copyright that they may have
@@ -17,6 +20,15 @@
 
 #include <portable/macros.h>
 
+/*
+ * Used for iterating through arrays.  ARRAY_SIZE returns the number of
+ * elements in the array (useful for a < upper bound in a for loop) and
+ * ARRAY_END returns a pointer to the element past the end (ISO C99 makes it
+ * legal to refer to such a pointer as long as it's never dereferenced).
+ */
+#define ARRAY_SIZE(array) (sizeof(array) / sizeof((array)[0]))
+#define ARRAY_END(array)  (&(array)[ARRAY_SIZE(array)])
+
 /* Used for unused parameters to silence gcc warnings. */
 #define UNUSED __attribute__((__unused__))
 
diff --git a/util/messages.c b/util/messages.c
index 01038d6..52fcfb7 100644
--- a/util/messages.c
+++ b/util/messages.c
@@ -50,6 +50,9 @@
  * generates given the format and arguments), a format, an argument list as a
  * va_list, and the applicable errno value (if any).
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Written by Russ Allbery <rra@stanford.edu>
  * Copyright 2008, 2009, 2010
  *     The Board of Trustees of the Leland Stanford Junior University
@@ -204,8 +207,8 @@ message_log_syslog(int pri, size_t len, const char *fmt, va_list args, int err)
 
     buffer = malloc(len + 1);
     if (buffer == NULL) {
-        fprintf(stderr, "failed to malloc %u bytes at %s line %d: %s",
-                len + 1, __FILE__, __LINE__, strerror(errno));
+        fprintf(stderr, "failed to malloc %lu bytes at %s line %d: %s",
+                (unsigned long) len + 1, __FILE__, __LINE__, strerror(errno));
         exit(message_fatal_cleanup ? (*message_fatal_cleanup)() : 1);
     }
     vsnprintf(buffer, len + 1, fmt, args);
diff --git a/util/messages.h b/util/messages.h
index 05dacac..0f8b5b6 100644
--- a/util/messages.h
+++ b/util/messages.h
@@ -1,6 +1,9 @@
 /*
  * Prototypes for message and error reporting (possibly fatal).
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Copyright 2008, 2010
  *     The Board of Trustees of the Leland Stanford Junior University
  * Copyright (c) 2004, 2005, 2006
@@ -91,7 +94,7 @@ void message_log_syslog_crit(size_t, const char *, va_list, int)
     __attribute__((__nonnull__));
 
 /* The type of a message handler. */
-typedef void (*message_handler_func)(size_t, const char *, va_list, int);
+typedef void (*message_handler_func)(unsigned int, const char *, va_list, int);
 
 /* If non-NULL, called before exit and its return value passed to exit. */
 extern int (*message_fatal_cleanup)(void);
diff --git a/util/network.c b/util/network.c
index 50d7f8d..b88f83b 100644
--- a/util/network.c
+++ b/util/network.c
@@ -10,6 +10,15 @@
  * implementations for functions that aren't found on some pre-IPv6 systems.
  * No other part of the source tree should have to care about IPv4 vs. IPv6.
  *
+ * In this file, casts through void * or const void * of struct sockaddr *
+ * parameters are to silence gcc warnings with -Wcast-align.  The specific
+ * address types often require stronger alignment than a struct sockaddr, and
+ * were originally allocated with that alignment.  GCC doesn't have a good way
+ * of knowing that this code is correct.
+ *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Written by Russ Allbery <rra@stanford.edu>
  * Copyright 2009, 2011
  *     The Board of Trustees of the Leland Stanford Junior University
@@ -39,7 +48,14 @@
 #include <portable/socket.h>
 
 #include <errno.h>
+#ifdef HAVE_SYS_SELECT_H
+# include <sys/select.h>
+#endif
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
 
+#include <util/fdflag.h>
 #include <util/messages.h>
 #include <util/network.h>
 #include <util/xmalloc.h>
@@ -218,7 +234,7 @@ network_bind_ipv6(const char *address, unsigned short port)
  */
 #if HAVE_INET6
 void
-network_bind_all(unsigned short port, int **fds, unsigned int *count)
+network_bind_all(unsigned short port, socket_type **fds, unsigned int *count)
 {
     struct addrinfo hints, *addrs, *addr;
     unsigned int size;
@@ -245,7 +261,7 @@ network_bind_all(unsigned short port, int **fds, unsigned int *count)
      * assuming an IPv6 and IPv4 socket, and grow it by two when necessary.
      */
     size = 2;
-    *fds = xmalloc(size * sizeof(int));
+    *fds = xmalloc(size * sizeof(socket_type));
     for (addr = addrs; addr != NULL; addr = addr->ai_next) {
         network_sockaddr_sprint(name, sizeof(name), addr->ai_addr);
         if (addr->ai_family == AF_INET)
@@ -285,6 +301,18 @@ network_bind_all(unsigned short port, socket_type **fds, unsigned int *count)
 
 
 /*
+ * Free the array of file descriptors allocated by network_bind_all.  This is
+ * a simple wrapper around free, needed on platforms where libraries allocate
+ * memory from a different memory domain than programs (such as Windows).
+ */
+void
+network_bind_all_free(socket_type *fds)
+{
+    free(fds);
+}
+
+
+/*
  * Given an array of file descriptors and the length of that array (the same
  * data that's returned by network_bind_all), wait for an incoming connection
  * on any of those sockets, accept the connection with accept(), and return
@@ -327,7 +355,10 @@ network_accept_any(socket_type fds[], unsigned int count,
             fd = fds[i];
             break;
         }
-    return accept(fd, addr, addrlen);
+    if (fd == INVALID_SOCKET)
+        return INVALID_SOCKET;
+    else
+        return accept(fd, addr, addrlen);
 }
 
 
@@ -336,18 +367,18 @@ network_accept_any(socket_type fds[], unsigned int count,
  * using the provided source address.  Returns true on success and false on
  * failure.
  */
-static int
+static bool
 network_source(socket_type fd, int family, const char *source)
 {
     if (source == NULL || strcmp(source, "all") == 0)
-        return 1;
+        return true;
     if (family == AF_INET) {
         struct sockaddr_in saddr;
 
         memset(&saddr, 0, sizeof(saddr));
         saddr.sin_family = AF_INET;
         if (!inet_aton(source, &saddr.sin_addr))
-            return 0;
+            return false;
         return bind(fd, (struct sockaddr *) &saddr, sizeof(saddr)) == 0;
     }
 #ifdef HAVE_INET6
@@ -357,7 +388,7 @@ network_source(socket_type fd, int family, const char *source)
         memset(&saddr, 0, sizeof(saddr));
         saddr.sin6_family = AF_INET6;
         if (inet_pton(AF_INET6, source, &saddr.sin6_addr) < 1)
-            return 0;
+            return false;
         return bind(fd, (struct sockaddr *) &saddr, sizeof(saddr)) == 0;
     }
 #endif
@@ -367,7 +398,7 @@ network_source(socket_type fd, int family, const char *source)
 #else
         socket_set_errno(EINVAL);
 #endif
-        return 0;
+        return false;
     }
 }
 
@@ -381,13 +412,15 @@ network_source(socket_type fd, int family, const char *source)
  * errno.
  */
 socket_type
-network_connect(struct addrinfo *ai, const char *source)
+network_connect(struct addrinfo *ai, const char *source, time_t timeout)
 {
     socket_type fd = INVALID_SOCKET;
-    int oerrno;
-    int success;
+    int oerrno, status, err;
+    socklen_t len;
+    struct timeval tv;
+    fd_set set;
 
-    for (success = 0; ai != NULL; ai = ai->ai_next) {
+    for (status = -1; status != 0 && ai != NULL; ai = ai->ai_next) {
         if (fd != INVALID_SOCKET)
             socket_close(fd);
         fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
@@ -395,15 +428,34 @@ network_connect(struct addrinfo *ai, const char *source)
             continue;
         if (!network_source(fd, ai->ai_family, source))
             continue;
-        if (connect(fd, ai->ai_addr, ai->ai_addrlen) == 0) {
-            success = 1;
-            break;
+        if (timeout == 0)
+            status = connect(fd, ai->ai_addr, ai->ai_addrlen);
+        else {
+            fdflag_nonblocking(fd, true);
+            status = connect(fd, ai->ai_addr, ai->ai_addrlen);
+            if (status < 0 && socket_errno == EINPROGRESS) {
+                tv.tv_sec = timeout;
+                tv.tv_usec = 0;
+                FD_ZERO(&set);
+                FD_SET(fd, &set);
+                status = select(fd + 1, NULL, &set, NULL, &tv);
+                if (status == 0 && !FD_ISSET(fd, &set)) {
+                    status = -1;
+                    socket_set_errno(ETIMEDOUT);
+                } else if (status > 0 && FD_ISSET(fd, &set)) {
+                    len = sizeof(err);
+                    status = getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &len);
+                    if (status == 0)
+                        status = err;
+                }
+            }
+            fdflag_nonblocking(fd, false);
         }
     }
-    if (success)
+    if (status == 0)
         return fd;
     else {
-        if (fd >= 0) {
+        if (fd != INVALID_SOCKET) {
             oerrno = socket_errno;
             socket_close(fd);
             socket_set_errno(oerrno);
@@ -421,7 +473,7 @@ network_connect(struct addrinfo *ai, const char *source)
  */
 socket_type
 network_connect_host(const char *host, unsigned short port,
-                     const char *source)
+                     const char *source, time_t timeout)
 {
     struct addrinfo hints, *ai;
     char portbuf[16];
@@ -434,7 +486,7 @@ network_connect_host(const char *host, unsigned short port,
     snprintf(portbuf, sizeof(portbuf), "%d", port);
     if (getaddrinfo(host, portbuf, &hints, &ai) != 0)
         return INVALID_SOCKET;
-    fd = network_connect(ai, source);
+    fd = network_connect(ai, source, timeout);
     oerrno = socket_errno;
     freeaddrinfo(ai);
     socket_set_errno(oerrno);
@@ -483,7 +535,7 @@ network_sockaddr_sprint(char *dst, size_t size, const struct sockaddr *addr)
     if (addr->sa_family == AF_INET6) {
         const struct sockaddr_in6 *sin6;
 
-        sin6 = (const struct sockaddr_in6 *) addr;
+        sin6 = (const struct sockaddr_in6 *) (const void *) addr;
         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
             struct in_addr in;
 
@@ -497,7 +549,7 @@ network_sockaddr_sprint(char *dst, size_t size, const struct sockaddr *addr)
     if (addr->sa_family == AF_INET) {
         const struct sockaddr_in *sin;
 
-        sin = (const struct sockaddr_in *) addr;
+        sin = (const struct sockaddr_in *) (const void *) addr;
         result = inet_ntop(AF_INET, &sin->sin_addr, dst, size);
         return (result != NULL);
     } else {
@@ -515,20 +567,26 @@ network_sockaddr_sprint(char *dst, size_t size, const struct sockaddr *addr)
 bool
 network_sockaddr_equal(const struct sockaddr *a, const struct sockaddr *b)
 {
-    const struct sockaddr_in *a4 = (const struct sockaddr_in *) a;
-    const struct sockaddr_in *b4 = (const struct sockaddr_in *) b;
-
+    const struct sockaddr_in *a4;
+    const struct sockaddr_in *b4;
 #ifdef HAVE_INET6
-    const struct sockaddr_in6 *a6 = (const struct sockaddr_in6 *) a;
-    const struct sockaddr_in6 *b6 = (const struct sockaddr_in6 *) b;
+    const struct sockaddr_in6 *a6;
+    const struct sockaddr_in6 *b6;
     const struct sockaddr *tmp;
+#endif
+
+    a4 = (const struct sockaddr_in *) (const void *) a;
+    b4 = (const struct sockaddr_in *) (const void *) b;
 
+#ifdef HAVE_INET6
+    a6 = (const struct sockaddr_in6 *) (const void *) a;
+    b6 = (const struct sockaddr_in6 *) (const void *) b;
     if (a->sa_family == AF_INET && b->sa_family == AF_INET6) {
         tmp = a;
         a = b;
         b = tmp;
-        a6 = (const struct sockaddr_in6 *) a;
-        b4 = (const struct sockaddr_in *) b;
+        a6 = (const struct sockaddr_in6 *) (const void *) a;
+        b4 = (const struct sockaddr_in *) (const void *) b;
     }
     if (a->sa_family == AF_INET6) {
         if (b->sa_family == AF_INET6)
@@ -564,14 +622,14 @@ network_sockaddr_port(const struct sockaddr *sa)
     const struct sockaddr_in6 *sin6;
 
     if (sa->sa_family == AF_INET6) {
-        sin6 = (const struct sockaddr_in6 *) sa;
+        sin6 = (const struct sockaddr_in6 *) (const void *) sa;
         return htons(sin6->sin6_port);
     }
 #endif
     if (sa->sa_family != AF_INET)
         return 0;
     else {
-        sin = (const struct sockaddr_in *) sa;
+        sin = (const struct sockaddr_in *) (const void *) sa;
         return htons(sin->sin_port);
     }
 }
diff --git a/util/network.h b/util/network.h
index d528a1a..5c4d981 100644
--- a/util/network.h
+++ b/util/network.h
@@ -1,6 +1,9 @@
 /*
  * Prototypes for network connection utility functions.
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Written by Russ Allbery <rra@stanford.edu>
  * Copyright 2009, 2010, 2011
  *     The Board of Trustees of the Leland Stanford Junior University
@@ -56,11 +59,13 @@ socket_type network_bind_ipv6(const char *address, unsigned short port)
  * and one for IPv6, if IPv6 support is enabled).  If IPv6 is not enabled,
  * just one socket will be created and bound to the IPv4 wildcard address.
  * fds will be set to an array containing the resulting file descriptors, with
- * count holding the count returned.
+ * count holding the count returned.  Use network_bind_all_free to free the
+ * array of file descriptors when no longer needed.
  */
 void network_bind_all(unsigned short port, socket_type **fds,
                       unsigned int *count)
     __attribute__((__nonnull__));
+void network_bind_all_free(socket_type *fds);
 
 /*
  * Accept an incoming connection from any file descriptor in an array.  This
@@ -78,9 +83,9 @@ socket_type network_accept_any(socket_type fds[], unsigned int count,
  * Create a socket and connect it to the remote service given by the linked
  * list of addrinfo structs.  Returns the new file descriptor on success and
  * -1 on failure, with the error left in errno.  Takes an optional source
- * address.
+ * address and a timeout in seconds, which may be 0 for no timeout.
  */
-socket_type network_connect(struct addrinfo *, const char *source)
+socket_type network_connect(struct addrinfo *, const char *source, time_t)
     __attribute__((__nonnull__(1)));
 
 /*
@@ -88,7 +93,7 @@ socket_type network_connect(struct addrinfo *, const char *source)
  * fails, errno may not be set to anything useful.
  */
 socket_type network_connect_host(const char *host, unsigned short port,
-                                 const char *source)
+                                 const char *source, time_t)
     __attribute__((__nonnull__(1)));
 
 /*
diff --git a/util/vector.c b/util/vector.c
index 5138438..285969c 100644
--- a/util/vector.c
+++ b/util/vector.c
@@ -20,6 +20,9 @@
  * and perform the same operations, but I'm leery of doing that as I'm not
  * sure if it's a violation of the C type aliasing rules.
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Written by Russ Allbery <rra@stanford.edu>
  *
  * The authors hereby relinquish any claim to any copyright that they may have
@@ -345,7 +348,7 @@ vector_split_multi(const char *string, const char *seps,
     if (vector->allocated < count)
         vector_resize(vector, count);
 
-    for (start = string, p = string, i = 0; *p; p++)
+    for (start = string, p = string, i = 0; *p != '\0'; p++)
         if (strchr(seps, *p) != NULL) {
             if (start != p)
                 vector->strings[i++] = xstrndup(start, p - start);
@@ -378,7 +381,7 @@ cvector_split_multi(char *string, const char *seps, struct cvector *vector)
     if (vector->allocated < count)
         cvector_resize(vector, count);
 
-    for (start = string, p = string, i = 0; *p; p++)
+    for (start = string, p = string, i = 0; *p != '\0'; p++)
         if (strchr(seps, *p) != NULL) {
             if (start != p) {
                 *p = '\0';
@@ -438,7 +441,7 @@ vector_split_space(const char *string, struct vector *vector)
     if (vector->allocated < count)
         vector_resize(vector, count);
 
-    for (start = string, p = string, i = 0; *p; p++)
+    for (start = string, p = string, i = 0; *p != '\0'; p++)
         if (*p == ' ' || *p == '\t') {
             if (start != p)
                 vector->strings[i++] = xstrndup(start, p - start);
@@ -470,7 +473,7 @@ cvector_split_space(char *string, struct cvector *vector)
     if (vector->allocated < count)
         cvector_resize(vector, count);
 
-    for (start = string, p = string, i = 0; *p; p++)
+    for (start = string, p = string, i = 0; *p != '\0'; p++)
         if (*p == ' ' || *p == '\t') {
             if (start != p) {
                 *p = '\0';
diff --git a/util/vector.h b/util/vector.h
index ac3bf18..6a872d3 100644
--- a/util/vector.h
+++ b/util/vector.h
@@ -8,6 +8,9 @@
  * Vectors require list of strings, not arbitrary binary data, and cannot
  * handle data elements containing nul characters.
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Written by Russ Allbery <rra@stanford.edu>
  *
  * The authors hereby relinquish any claim to any copyright that they may have
@@ -97,7 +100,9 @@ void cvector_free(struct cvector *)
  * Empty strings will yield zero-length vectors.  Adjacent delimiters are
  * treated as a single delimiter by *_split_space and *_split_multi, but *not*
  * by *_split, so callers of *_split should be prepared for zero-length
- * strings in the vector.
+ * strings in the vector.  *_split_space and *_split_multi ignore any leading
+ * or trailing delimiters, so those functions will never create zero-length
+ * strings (similar to the behavior of strtok).
  */
 struct vector *vector_split(const char *string, char sep, struct vector *)
     __attribute__((__nonnull__(1)));
diff --git a/util/xmalloc.c b/util/xmalloc.c
index 0803999..839f5a0 100644
--- a/util/xmalloc.c
+++ b/util/xmalloc.c
@@ -55,6 +55,9 @@
  * header file defines macros named xmalloc, etc. that pass the file name and
  * line number to these functions.
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Copyright (c) 2004, 2005, 2006
  *     by Internet Systems Consortium, Inc. ("ISC")
  * Copyright (c) 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
diff --git a/util/xmalloc.h b/util/xmalloc.h
index 5447335..14d8831 100644
--- a/util/xmalloc.h
+++ b/util/xmalloc.h
@@ -1,6 +1,9 @@
 /*
  * Prototypes for malloc routines with failure handling.
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Copyright 2010
  *     The Board of Trustees of the Leland Stanford Junior University
  * Copyright (c) 2004, 2005, 2006
diff --git a/util/xwrite.c b/util/xwrite.c
index 7e27654..8d472a7 100644
--- a/util/xwrite.c
+++ b/util/xwrite.c
@@ -21,6 +21,9 @@
  * written, on the subsequent additional write; in that case, these functions
  * will return -1 and the number of bytes actually written will be lost.
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Copyright 2008
  *     The Board of Trustees of the Leland Stanford Junior University
  * Copyright (c) 2004, 2005, 2006
diff --git a/util/xwrite.h b/util/xwrite.h
index d79e801..2822727 100644
--- a/util/xwrite.h
+++ b/util/xwrite.h
@@ -1,6 +1,9 @@
 /*
  * Prototypes for write and writev replacements to handle partial writes.
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Copyright 2008, 2010
  *     The Board of Trustees of the Leland Stanford Junior University
  * Copyright (c) 2004, 2005, 2006