klibc - Jul 2011 - [PATCH 1/3] klibc: Add scandir() and alphasort() support.

Add support for scandir() and alphasort() as defined in POSIX.1-2008.

Signed-off-by: Mike Waychison <mikew at google.com>
---
 usr/include/dirent.h |    7 +++++
 usr/klibc/Kbuild     |    2 +
 usr/klibc/scandir.c  |   76 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 84 insertions(+), 1 deletions(-)
 create mode 100644 usr/klibc/scandir.c

diff --git a/usr/include/dirent.h b/usr/include/dirent.h
index e324474..3b1ff59 100644
--- a/usr/include/dirent.h
+++ b/usr/include/dirent.h
@@ -30,4 +30,11 @@ static __inline__ int dirfd(DIR * __d)
 	return __d->__fd;
 }
 
+__extern int scandir(const char *dirp, struct dirent ***namelist,
+		     int (*filter)(const struct dirent *),
+		     int (*compar)(const struct dirent **,
+				   const struct dirent **));
+
+int alphasort(const struct dirent **a, const struct dirent **b);
+
 #endif				/* _DIRENT_H */
diff --git a/usr/klibc/Kbuild b/usr/klibc/Kbuild
index af40367..40e61da 100644
--- a/usr/klibc/Kbuild
+++ b/usr/klibc/Kbuild
@@ -42,7 +42,7 @@ klib-y := vsnprintf.o snprintf.o vsprintf.o sprintf.o \
 	  seteuid.o setegid.o \
 	  getenv.o setenv.o putenv.o __put_env.o unsetenv.o \
 	  clearenv.o nullenv.o \
-	  getopt.o getopt_long.o readdir.o remove.o \
+	  getopt.o getopt_long.o readdir.o scandir.o remove.o \
 	  syslog.o closelog.o pty.o getpt.o posix_openpt.o isatty.o reboot.o \
 	  time.o utime.o llseek.o nice.o getpriority.o \
 	  qsort.o bsearch.o \
diff --git a/usr/klibc/scandir.c b/usr/klibc/scandir.c
new file mode 100644
index 0000000..1f58b15
--- /dev/null
+++ b/usr/klibc/scandir.c
@@ -0,0 +1,76 @@
+/*
+ * scandir.c: scandir/alphasort
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <dirent.h>
+
+int scandir(const char *dirp, struct dirent ***namelist,
+	    int (*filter)(const struct dirent *),
+	    int (*compar)(const struct dirent **, const struct dirent **))
+{
+	struct dirent **nl = NULL, **next_nl;
+	struct dirent *dirent;
+	size_t count = 0;
+	size_t allocated = 0;
+	DIR *dir;
+
+	dir = opendir(dirp);
+	if (!dir)
+		return -1;
+
+	while (1) {
+		dirent = readdir(dir);
+		if (!dirent)
+			break;
+		if (!filter || filter(dirent)) {
+			struct dirent *copy;
+			copy = malloc(sizeof(*copy));
+			if (!copy)
+				goto cleanup_fail;
+			memcpy(copy, dirent, sizeof(*copy));
+
+			/* Extend the array if needed */
+			if (count == allocated) {
+				if (allocated == 0)
+					allocated = 15; /* ~1 page worth */
+				else
+					allocated *= 2;
+				next_nl = realloc(nl, allocated);
+				if (!next_nl) {
+					free(copy);
+					goto cleanup_fail;
+				}
+				nl = next_nl;
+			}
+
+			nl[count++] = copy;
+		}
+	}
+
+	qsort(nl, count, sizeof(struct dirent *),
+	      (int (*)(const void *, const void *))compar);
+
+	closedir(dir);
+
+	*namelist = nl;
+	return count;
+
+cleanup_fail:
+	while (count) {
+		dirent = nl[--count];
+		free(dirent);
+	}
+	free(nl);
+	closedir(dir);
+	errno = ENOMEM;
+	return -1;
+}
+
+int alphasort(const struct dirent **a, const struct dirent **b)
+{
+	return strcmp((*a)->d_name, (*b)->d_name);
+}

Add support for scandir() and alphasort() as defined in POSIX.1-2008.

Signed-off-by: Mike Waychison <mikew at google.com>
---
 usr/include/dirent.h |    7 +++++
 usr/klibc/Kbuild     |    2 +
 usr/klibc/scandir.c  |   76 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 84 insertions(+), 1 deletions(-)
 create mode 100644 usr/klibc/scandir.c

diff --git a/usr/include/dirent.h b/usr/include/dirent.h
index e324474..3b1ff59 100644
--- a/usr/include/dirent.h
+++ b/usr/include/dirent.h
@@ -30,4 +30,11 @@ static __inline__ int dirfd(DIR * __d)
 	return __d->__fd;
 }
 
+__extern int scandir(const char *dirp, struct dirent ***namelist,
+		     int (*filter)(const struct dirent *),
+		     int (*compar)(const struct dirent **,
+				   const struct dirent **));
+
+int alphasort(const struct dirent **a, const struct dirent **b);
+
 #endif				/* _DIRENT_H */
diff --git a/usr/klibc/Kbuild b/usr/klibc/Kbuild
index af40367..40e61da 100644
--- a/usr/klibc/Kbuild
+++ b/usr/klibc/Kbuild
@@ -42,7 +42,7 @@ klib-y := vsnprintf.o snprintf.o vsprintf.o sprintf.o \
 	  seteuid.o setegid.o \
 	  getenv.o setenv.o putenv.o __put_env.o unsetenv.o \
 	  clearenv.o nullenv.o \
-	  getopt.o getopt_long.o readdir.o remove.o \
+	  getopt.o getopt_long.o readdir.o scandir.o remove.o \
 	  syslog.o closelog.o pty.o getpt.o posix_openpt.o isatty.o reboot.o \
 	  time.o utime.o llseek.o nice.o getpriority.o \
 	  qsort.o bsearch.o \
diff --git a/usr/klibc/scandir.c b/usr/klibc/scandir.c
new file mode 100644
index 0000000..1f58b15
--- /dev/null
+++ b/usr/klibc/scandir.c
@@ -0,0 +1,76 @@
+/*
+ * scandir.c: scandir/alphasort
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <dirent.h>
+
+int scandir(const char *dirp, struct dirent ***namelist,
+	    int (*filter)(const struct dirent *),
+	    int (*compar)(const struct dirent **, const struct dirent **))
+{
+	struct dirent **nl = NULL, **next_nl;
+	struct dirent *dirent;
+	size_t count = 0;
+	size_t allocated = 0;
+	DIR *dir;
+
+	dir = opendir(dirp);
+	if (!dir)
+		return -1;
+
+	while (1) {
+		dirent = readdir(dir);
+		if (!dirent)
+			break;
+		if (!filter || filter(dirent)) {
+			struct dirent *copy;
+			copy = malloc(sizeof(*copy));
+			if (!copy)
+				goto cleanup_fail;
+			memcpy(copy, dirent, sizeof(*copy));
+
+			/* Extend the array if needed */
+			if (count == allocated) {
+				if (allocated == 0)
+					allocated = 15; /* ~1 page worth */
+				else
+					allocated *= 2;
+				next_nl = realloc(nl, allocated);
+				if (!next_nl) {
+					free(copy);
+					goto cleanup_fail;
+				}
+				nl = next_nl;
+			}
+
+			nl[count++] = copy;
+		}
+	}
+
+	qsort(nl, count, sizeof(struct dirent *),
+	      (int (*)(const void *, const void *))compar);
+
+	closedir(dir);
+
+	*namelist = nl;
+	return count;
+
+cleanup_fail:
+	while (count) {
+		dirent = nl[--count];
+		free(dirent);
+	}
+	free(nl);
+	closedir(dir);
+	errno = ENOMEM;
+	return -1;
+}
+
+int alphasort(const struct dirent **a, const struct dirent **b)
+{
+	return strcmp((*a)->d_name, (*b)->d_name);
+}

This patch implements support for executing files present in drop
directories.  This is implemented by a new function called run_scripts,
which takes the name of the base drop-directory to search for scripts.

It is implemented by simply doing a single-depth search for files
present in the directory using scandir().  It then will synchronously
execute each file in order.  Failure to execute anything that looks like
a file is treated as a fatal error, which should be easy to catch as
these directories are essentially configuration directories and failure
to execute should be immediately visible to developers.

Execution is implemented as a simple fork/exec, passing all the command
line flags in as the arguments to the executed script/binary.

Signed-off-by: Mike Waychison <mikew at google.com>
---
 usr/kinit/Kbuild        |    2 -
 usr/kinit/kinit.h       |    2 +
 usr/kinit/run_scripts.c |  110 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 113 insertions(+), 1 deletions(-)
 create mode 100644 usr/kinit/run_scripts.c

diff --git a/usr/kinit/Kbuild b/usr/kinit/Kbuild
index ff1d449..b743b87 100644
--- a/usr/kinit/Kbuild
+++ b/usr/kinit/Kbuild
@@ -8,7 +8,7 @@ lib-y   := name_to_dev.o devname.o getarg.o
 kinit-y  := lib.a
 
 kinit-y  += kinit.o do_mounts.o ramdisk_load.o initrd.o
-kinit-y  += getintfile.o readfile.o xpio.o
+kinit-y  += getintfile.o readfile.o xpio.o run_scripts.o
 kinit-y  += do_mounts_md.o do_mounts_mtd.o nfsroot.o
 
 kinit-y  += ipconfig/
diff --git a/usr/kinit/kinit.h b/usr/kinit/kinit.h
index c2e67b7..808deee 100644
--- a/usr/kinit/kinit.h
+++ b/usr/kinit/kinit.h
@@ -65,4 +65,6 @@ static inline void dump_args(int argc, char *argv[])
 }
 #endif
 
+void run_scripts(const char *basepath, int cmdc, char **cmdv);
+
 #endif				/* KINIT_H */
diff --git a/usr/kinit/run_scripts.c b/usr/kinit/run_scripts.c
new file mode 100644
index 0000000..4609b39
--- /dev/null
+++ b/usr/kinit/run_scripts.c
@@ -0,0 +1,110 @@
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <dirent.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "kinit.h"
+
+static int is_file(const struct dirent *dirent)
+{
+	return (dirent->d_type == DT_REG);
+}
+
+static void run_script(const char *basepath, const char *filename,
+		       int cmdc, char **cmdv)
+{
+	char *fullpath;
+	char **args;
+	pid_t pid;
+	int status;
+	int ret;
+	int i;
+
+	/* Figure out fullpath */
+	fullpath = malloc(strlen(basepath) + strlen(filename) + 2);
+	if (!fullpath) {
+		fprintf(stderr, "Ran out of memory!\n");
+		exit(1);
+	}
+	sprintf(fullpath, "%s/%s", basepath, filename);
+
+	/* Prepare args for call */
+	args = malloc(sizeof(*args) * (cmdc + 2)); /* NULL + ARGV[0} */
+	if (!args) {
+		fprintf(stderr, "Ran out of memory!\n");
+		free(fullpath);
+		exit(1);
+	}
+	args[0] = fullpath;
+	for (i = 0; i < cmdc; i++)
+		args[i + 1] = cmdv[i];
+	args[cmdc + 1] = NULL;
+
+	/* Run the child */
+	pid = fork();
+	if (pid == -1) {
+		fprintf(stderr, "Failed to fork in run_scripts(%s)\n",
+			basepath);
+		exit(1);
+	}
+	if (pid == 0) {
+		/* Child */
+		execv(fullpath, args);
+		fprintf(stderr, "Failed to exec %s: %s\n", fullpath,
+			strerror(errno));
+		exit(1);
+	}
+
+	/* Parent */
+	while (1) {
+		ret = waitpid(pid, &status, 0);
+		if (ret == pid)
+			break;
+		if (ret == -1 && errno == EINTR)
+			continue;
+		fprintf(stderr, "failed to wait on child: ret=%d errno=%d\n",
+			ret, errno);
+		exit(1);
+	}
+
+	if (WIFEXITED(status)) {
+		if (WEXITSTATUS(status) != 0)
+			fprintf(stderr, "%s exited with status: %d\n",
+				fullpath, WEXITSTATUS(status));
+	} else if (WIFSIGNALED(status)) {
+		fprintf(stderr, "%s terminated by signal %d\n",
+			fullpath, WTERMSIG(status));
+	} else {
+		fprintf(stderr, "Failed to understand status code 0x%x\n",
+			status);
+	}
+
+	free(args);
+	free(fullpath);
+}
+
+void run_scripts(const char *basepath, int cmdc, char **cmdv)
+{
+	struct dirent **namelist;
+	int i;
+	int count;
+
+	count = scandir(basepath, &namelist, is_file, alphasort);
+	if (count < 0) {
+		if (errno == ENOENT)
+			return;
+		fprintf(stderr, "WARNING: could not run_scripts(%s): %s\n",
+			basepath, strerror(errno));
+		return;
+	}
+
+	for (i = 0; i < count; i++) {
+		run_script(basepath, namelist[i]->d_name, cmdc, cmdv);
+		free(namelist[i]);
+	}
+	free(namelist);
+}

On Fri, 29 Jul 2011, Mike Waychison wrote:
> Add support for scandir() and alphasort() as defined in POSIX.1-2008.
> 
> Signed-off-by: Mike Waychison <mikew at google.com>
> ---
>  usr/include/dirent.h |    7 +++++
>  usr/klibc/Kbuild     |    2 +
>  usr/klibc/scandir.c  |   76
++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 84 insertions(+), 1 deletions(-)
>  create mode 100644 usr/klibc/scandir.c
> 
> diff --git a/usr/include/dirent.h b/usr/include/dirent.h
> index e324474..3b1ff59 100644
> --- a/usr/include/dirent.h
> +++ b/usr/include/dirent.h
> @@ -30,4 +30,11 @@ static __inline__ int dirfd(DIR * __d)
>  	return __d->__fd;
>  }
>  
> +__extern int scandir(const char *dirp, struct dirent ***namelist,
> +		     int (*filter)(const struct dirent *),
> +		     int (*compar)(const struct dirent **,
> +				   const struct dirent **));
> +
> +int alphasort(const struct dirent **a, const struct dirent **b);
> +
>  #endif				/* _DIRENT_H */
please no names in the header files, it breaks macros.

ah and alphasort needs __extern too.
> diff --git a/usr/klibc/Kbuild b/usr/klibc/Kbuild
> index af40367..40e61da 100644
> --- a/usr/klibc/Kbuild
> +++ b/usr/klibc/Kbuild
> @@ -42,7 +42,7 @@ klib-y := vsnprintf.o snprintf.o vsprintf.o sprintf.o \
>  	  seteuid.o setegid.o \
>  	  getenv.o setenv.o putenv.o __put_env.o unsetenv.o \
>  	  clearenv.o nullenv.o \
> -	  getopt.o getopt_long.o readdir.o remove.o \
> +	  getopt.o getopt_long.o readdir.o scandir.o remove.o \
>  	  syslog.o closelog.o pty.o getpt.o posix_openpt.o isatty.o reboot.o \
>  	  time.o utime.o llseek.o nice.o getpriority.o \
>  	  qsort.o bsearch.o \
please put alphasort in separate file.
> diff --git a/usr/klibc/scandir.c b/usr/klibc/scandir.c
> new file mode 100644
> index 0000000..1f58b15
> --- /dev/null
> +++ b/usr/klibc/scandir.c
> @@ -0,0 +1,76 @@
> +/*
> + * scandir.c: scandir/alphasort
> + */
> +
> +#include <stdlib.h>
> +#include <string.h>
> +#include <errno.h>
> +
> +#include <dirent.h>
> +
> +int scandir(const char *dirp, struct dirent ***namelist,
> +	    int (*filter)(const struct dirent *),
> +	    int (*compar)(const struct dirent **, const struct dirent **))
> +{
> +	struct dirent **nl = NULL, **next_nl;
> +	struct dirent *dirent;
> +	size_t count = 0;
> +	size_t allocated = 0;
> +	DIR *dir;
> +
> +	dir = opendir(dirp);
> +	if (!dir)
> +		return -1;
> +
> +	while (1) {
> +		dirent = readdir(dir);
> +		if (!dirent)
> +			break;
> +		if (!filter || filter(dirent)) {
> +			struct dirent *copy;
> +			copy = malloc(sizeof(*copy));
> +			if (!copy)
> +				goto cleanup_fail;
> +			memcpy(copy, dirent, sizeof(*copy));
> +
> +			/* Extend the array if needed */
> +			if (count == allocated) {
> +				if (allocated == 0)
> +					allocated = 15; /* ~1 page worth */
> +				else
> +					allocated *= 2;
> +				next_nl = realloc(nl, allocated);
> +				if (!next_nl) {
> +					free(copy);
> +					goto cleanup_fail;
> +				}
> +				nl = next_nl;
> +			}
> +
> +			nl[count++] = copy;
> +		}
> +	}
> +
> +	qsort(nl, count, sizeof(struct dirent *),
> +	      (int (*)(const void *, const void *))compar);
> +
> +	closedir(dir);
> +
> +	*namelist = nl;
> +	return count;
> +
> +cleanup_fail:
> +	while (count) {
> +		dirent = nl[--count];
> +		free(dirent);
> +	}
> +	free(nl);
> +	closedir(dir);
> +	errno = ENOMEM;
> +	return -1;
> +}
> +
> +int alphasort(const struct dirent **a, const struct dirent **b)
> +{
> +	return strcmp((*a)->d_name, (*b)->d_name);
> +}
other then that looks good, thanks to hpa for quick review.

-- 
maks

P.S. need to fix the sys/capability.h too.