Patch based on commits by Dave Vasilevsky <dave@vasilevsky.ca> and
Blake Riley <blake.riley@gmail.com>, squashed into a single patch,
with BSD-specific changes omitted.

See also https://github.com/plougher/squashfs-tools/pull/69.

diff --git a/squashfs-tools/action.c b/squashfs-tools/action.c
index 4b06ccb..3cad2ab 100644
--- a/squashfs-tools/action.c
+++ b/squashfs-tools/action.c
@@ -39,6 +39,10 @@
 #include <errno.h>
 #include <ctype.h>
 
+#ifndef FNM_EXTMATCH /* glibc extension */
+	#define FNM_EXTMATCH 0
+#endif
+
 #include "squashfs_fs.h"
 #include "mksquashfs.h"
 #include "action.h"
@@ -2414,9 +2418,12 @@ static char *get_start(char *s, int n)
 
 static int subpathname_fn(struct atom *atom, struct action_data *action_data)
 {
-	return fnmatch(atom->argv[0], get_start(strdupa(action_data->subpath),
+	char *path = strdup(action_data->subpath);
+	int is_match = fnmatch(atom->argv[0], get_start(path,
 		count_components(atom->argv[0])),
 		FNM_PATHNAME|FNM_EXTMATCH) == 0;
+	free(path);
+	return is_match;
 }
 
 /*
diff --git a/squashfs-tools/info.c b/squashfs-tools/info.c
index fe23d78..5c2f835 100644
--- a/squashfs-tools/info.c
+++ b/squashfs-tools/info.c
@@ -144,31 +144,22 @@ void dump_state()
 void *info_thrd(void *arg)
 {
 	sigset_t sigmask;
-	struct timespec timespec = { .tv_sec = 1, .tv_nsec = 0 };
-	int sig, waiting = 0;
+	int sig, err, waiting = 0;
 
 	sigemptyset(&sigmask);
 	sigaddset(&sigmask, SIGQUIT);
 	sigaddset(&sigmask, SIGHUP);
+	sigaddset(&sigmask, SIGALRM);
 
 	while(1) {
-		if(waiting)
-			sig = sigtimedwait(&sigmask, NULL, &timespec);
-		else
-			sig = sigwaitinfo(&sigmask, NULL);
+		err = sigwait(&sigmask, &sig);
 
-		if(sig == -1) {
+		if(err == -1) {
 			switch(errno) {
-			case EAGAIN:
-				/* interval timed out */
-				waiting = 0;
-				/* FALLTHROUGH */
 			case EINTR:
-				/* if waiting, the wait will be longer, but
-				   that's OK */
 				continue;
 			default:
-				BAD_ERROR("sigtimedwait/sigwaitinfo failed "
+				BAD_ERROR("sigwait failed "
 					"because %s\n", strerror(errno));
 			}
 		}
@@ -179,8 +170,12 @@ void *info_thrd(void *arg)
 			/* set one second interval period, if ^\ received
 			   within then, dump queue and cache status */
 			waiting = 1;
-		} else
+			alarm(1);
+		} else if (sig == SIGQUIT) {
 			dump_state();
+		} else if (sig == SIGALRM) {
+			waiting = 0;
+		}
 	}
 }
 
diff --git a/squashfs-tools/mksquashfs.c b/squashfs-tools/mksquashfs.c
index a45b77f..3607448 100644
--- a/squashfs-tools/mksquashfs.c
+++ b/squashfs-tools/mksquashfs.c
@@ -35,7 +35,12 @@
 #include <stddef.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#ifndef linux
+#include <sys/sysctl.h>
+#else
+#include <sys/sysinfo.h>
 #include <sys/sysmacros.h>
+#endif
 #include <fcntl.h>
 #include <errno.h>
 #include <dirent.h>
@@ -50,7 +55,10 @@
 #include <sys/wait.h>
 #include <limits.h>
 #include <ctype.h>
-#include <sys/sysinfo.h>
+
+#ifndef FNM_EXTMATCH /* glibc extension */
+	#define FNM_EXTMATCH 0
+#endif
 
 #ifndef linux
 #include <sys/sysctl.h>
@@ -5022,6 +5030,7 @@ static void initialise_threads(int readq, int fragq, int bwriteq, int fwriteq,
 	sigemptyset(&sigmask);
 	sigaddset(&sigmask, SIGQUIT);
 	sigaddset(&sigmask, SIGHUP);
+	sigaddset(&sigmask, SIGALRM);
 	if(pthread_sigmask(SIG_BLOCK, &sigmask, NULL) != 0)
 		BAD_ERROR("Failed to set signal mask in intialise_threads\n");
 
@@ -5760,6 +5769,35 @@ static int get_physical_memory()
 	long long page_size = sysconf(_SC_PAGESIZE);
 	int phys_mem;
 
+#ifndef linux
+	#ifdef HW_MEMSIZE
+		#define SYSCTL_PHYSMEM HW_MEMSIZE
+	#elif defined(HW_PHYSMEM64)
+		#define SYSCTL_PHYSMEM HW_PHYSMEM64
+	#else
+		#define SYSCTL_PHYSMEM HW_PHYSMEM
+	#endif
+
+	int mib[2];
+	uint64_t sysctl_physmem = 0;
+	size_t sysctl_len = sizeof(sysctl_physmem);
+
+	mib[0] = CTL_HW;
+	mib[1] = SYSCTL_PHYSMEM;
+
+	if(sysctl(mib, 2, &sysctl_physmem, &sysctl_len, NULL, 0) == 0) {
+		/* some systems use 32-bit values, work with what we're given */
+		if (sysctl_len == 4)
+			sysctl_physmem = *(uint32_t*)&sysctl_physmem;
+		phys_mem = sysctl_physmem >> 20;
+	} else {
+		ERROR_START("Failed to get amount of available "
+			"memory.");
+		ERROR_EXIT("  Defaulting to least viable amount\n");
+		phys_mem = SQUASHFS_LOWMEM;
+	}
+  #undef SYSCTL_PHYSMEM
+#else
 	if(num_pages == -1 || page_size == -1) {
 		struct sysinfo sys;
 		int res = sysinfo(&sys);
@@ -5772,6 +5810,7 @@ static int get_physical_memory()
 	}
 
 	phys_mem = num_pages * page_size >> 20;
+#endif
 
 	if(phys_mem < SQUASHFS_LOWMEM)
 		BAD_ERROR("Mksquashfs requires more physical memory than is "
diff --git a/squashfs-tools/read_xattrs.c b/squashfs-tools/read_xattrs.c
index 4debedf..3257c30 100644
--- a/squashfs-tools/read_xattrs.c
+++ b/squashfs-tools/read_xattrs.c
@@ -31,13 +31,13 @@
 #include <stdio.h>
 #include <string.h>
 
+#include <stdlib.h>
+
 #include "squashfs_fs.h"
 #include "squashfs_swap.h"
 #include "xattr.h"
 #include "error.h"
 
-#include <stdlib.h>
-
 extern int read_fs_bytes(int, long long, int, void *);
 extern int read_block(int, long long, long long *, int, void *);
 
diff --git a/squashfs-tools/unsquashfs.c b/squashfs-tools/unsquashfs.c
index 727f1d5..c1a6183 100644
--- a/squashfs-tools/unsquashfs.c
+++ b/squashfs-tools/unsquashfs.c
@@ -32,8 +32,12 @@
 #include "stdarg.h"
 #include "fnmatch_compat.h"
 
+#ifndef linux
+#include <sys/sysctl.h>
+#else
 #include <sys/sysinfo.h>
 #include <sys/sysmacros.h>
+#endif
 #include <sys/types.h>
 #include <sys/time.h>
 #include <sys/resource.h>
@@ -1175,7 +1179,7 @@ int create_inode(char *pathname, struct inode *i)
 			break;
 		case SQUASHFS_SYMLINK_TYPE:
 		case SQUASHFS_LSYMLINK_TYPE: {
-			struct timespec times[2] = {
+			struct timeval times[2] = {
 				{ i->time, 0 },
 				{ i->time, 0 }
 			};
@@ -1194,8 +1198,7 @@ int create_inode(char *pathname, struct inode *i)
 				goto failed;
 			}
 
-			res = utimensat(AT_FDCWD, pathname, times,
-					AT_SYMLINK_NOFOLLOW);
+			res = lutimes(pathname, times);
 			if(res == -1) {
 				EXIT_UNSQUASH_STRICT("create_inode: failed to"
 					" set time on %s, because %s\n",
@@ -2683,6 +2686,7 @@ void initialise_threads(int fragment_buffer_size, int data_buffer_size, int cat_
 		sigemptyset(&sigmask);
 		sigaddset(&sigmask, SIGQUIT);
 		sigaddset(&sigmask, SIGHUP);
+		sigaddset(&sigmask, SIGALRM);
 		if(pthread_sigmask(SIG_BLOCK, &sigmask, NULL) != 0)
 			EXIT_UNSQUASH("Failed to set signal mask in initialise_threads\n");
 
diff --git a/squashfs-tools/unsquashfs.h b/squashfs-tools/unsquashfs.h
index 934618b..0e680ab 100644
--- a/squashfs-tools/unsquashfs.h
+++ b/squashfs-tools/unsquashfs.h
@@ -46,6 +46,10 @@
 #include <sys/ioctl.h>
 #include <sys/time.h>
 
+#ifndef FNM_EXTMATCH /* glibc extension */
+	#define FNM_EXTMATCH 0
+#endif
+
 #include "endian_compat.h"
 #include "squashfs_fs.h"
 #include "unsquashfs_error.h"
diff --git a/squashfs-tools/unsquashfs_info.c b/squashfs-tools/unsquashfs_info.c
index c8e2b9b..7d4f7af 100644
--- a/squashfs-tools/unsquashfs_info.c
+++ b/squashfs-tools/unsquashfs_info.c
@@ -96,31 +96,22 @@ void dump_state()
 void *info_thrd(void *arg)
 {
 	sigset_t sigmask;
-	struct timespec timespec = { .tv_sec = 1, .tv_nsec = 0 };
-	int sig, waiting = 0;
+	int sig, err, waiting = 0;
 
 	sigemptyset(&sigmask);
 	sigaddset(&sigmask, SIGQUIT);
 	sigaddset(&sigmask, SIGHUP);
+	sigaddset(&sigmask, SIGALRM);
 
 	while(1) {
-		if(waiting)
-			sig = sigtimedwait(&sigmask, NULL, &timespec);
-		else
-			sig = sigwaitinfo(&sigmask, NULL);
+		err = sigwait(&sigmask, &sig);
 
-		if(sig == -1) {
+		if(err == -1) {
 			switch(errno) {
-			case EAGAIN:
-				/* interval timed out */
-				waiting = 0;
-				/* FALLTHROUGH */
 			case EINTR:
-				/* if waiting, the wait will be longer, but
-				   that's OK */
 				continue;
 			default:
-				BAD_ERROR("sigtimedwait/sigwaitinfo failed "
+				BAD_ERROR("sigwait failed "
 					"because %s\n", strerror(errno));
 			}
 		}
@@ -132,8 +123,12 @@ void *info_thrd(void *arg)
 			/* set one second interval period, if ^\ received
 			   within then, dump queue and cache status */
 			waiting = 1;
-		} else
+			alarm(1);
+		} else if (sig == SIGQUIT) {
 			dump_state();
+		} else if (sig == SIGALRM) {
+			waiting = 0;
+		}
 	}
 }
 
diff --git a/squashfs-tools/unsquashfs_xattr.c b/squashfs-tools/unsquashfs_xattr.c
index 7742dfe..f8cd3b6 100644
--- a/squashfs-tools/unsquashfs_xattr.c
+++ b/squashfs-tools/unsquashfs_xattr.c
@@ -27,6 +27,11 @@
 
 #include <sys/xattr.h>
 
+#ifdef XATTR_NOFOLLOW /* Apple's xattrs */
+	#define lsetxattr(path_, name_, val_, sz_, flags_) \
+		setxattr(path_, name_, val_, sz_, 0, flags_ | XATTR_NOFOLLOW)
+#endif
+
 #define NOSPACE_MAX 10
 
 extern int root_process;
diff --git a/squashfs-tools/xattr.c b/squashfs-tools/xattr.c
index 64dfd82..d82d186 100644
--- a/squashfs-tools/xattr.c
+++ b/squashfs-tools/xattr.c
@@ -22,6 +22,14 @@
  * xattr.c
  */
 
+#ifndef linux
+#define __BYTE_ORDER BYTE_ORDER
+#define __BIG_ENDIAN BIG_ENDIAN
+#define __LITTLE_ENDIAN LITTLE_ENDIAN
+#else
+#include <endian.h>
+#endif
+
 #define TRUE 1
 #define FALSE 0
 
@@ -36,6 +44,13 @@
 #include <stdlib.h>
 #include <sys/xattr.h>
 
+#ifdef XATTR_NOFOLLOW /* Apple's xattrs */
+	#define llistxattr(path_, buf_, sz_) \
+		listxattr(path_, buf_, sz_, XATTR_NOFOLLOW)
+	#define lgetxattr(path_, name_, val_, sz_) \
+		getxattr(path_, name_, val_, sz_, 0, XATTR_NOFOLLOW)
+#endif
+
 #include "squashfs_fs.h"
 #include "squashfs_swap.h"
 #include "mksquashfs.h"
-- 
2.23.0