lib/, src/: Use SNPRINTF() instead of its pattern

The variable declarations for the buffers have been aligned in this
commit, so that they appear in the diff, making it easier to review.

Some important but somewhat tangent changes included in this commit:

-  lib/nss.c: The size was being defined as 65, but then used as 64.
   That was a bug, although not an important one; we were just wasting
   one byte.  Fix that while we replace snprintf() by SNPRINTF(), which
   will get the size from sizeof(), and thus will use the real size.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

lib/commonio.c

@@ -32,6 +32,7 @@
 #include "prototypes.h"
 #include "commonio.h"
 #include "shadowlog_internal.h"
+#include "string/sprintf.h"
 
 
 /* local function prototypes */
@@ -123,11 +124,11 @@ static int check_link_count (const char *file, bool log)
 
 static int do_lock_file (const char *file, const char *lock, bool log)
 {
-	int fd;
-	pid_t pid;
-	ssize_t len;
-	int retval;
-	char buf[32];
+	int      fd;
+	int      retval;
+	char     buf[32];
+	pid_t    pid;
+	ssize_t  len;
 
 	fd = open (file, O_CREAT | O_TRUNC | O_WRONLY, 0600);
 	if (-1 == fd) {
@@ -140,7 +141,7 @@ static int do_lock_file (const char *file, const char *lock, bool log)
 	}
 
 	pid = getpid ();
-	snprintf (buf, sizeof buf, "%lu", (unsigned long) pid);
+	SNPRINTF(buf, "%lu", (unsigned long) pid);
 	len = (ssize_t) strlen (buf) + 1;
 	if (write_full(fd, buf, len) == -1) {
 		if (log) {
@@ -341,7 +342,7 @@ static void free_linked_list (struct commonio_db *db)
 
 int commonio_setname (struct commonio_db *db, const char *name)
 {
-	snprintf (db->filename, sizeof (db->filename), "%s", name);
+	SNPRINTF(db->filename, "%s", name);
 	db->setname = true;
 	return 1;
 }
@@ -467,7 +468,7 @@ static void dec_lock_count (void)
 
 int commonio_unlock (struct commonio_db *db)
 {
-	char lock[1029];
+	char  lock[1029];
 
 	if (db->isopen) {
 		db->readonly = true;
@@ -484,7 +485,7 @@ int commonio_unlock (struct commonio_db *db)
 		 * then call ulckpwdf() (if used) on last unlock.
 		 */
 		db->locked = false;
-		snprintf (lock, sizeof lock, "%s.lock", db->filename);
+		SNPRINTF(lock, "%s.lock", db->filename);
 		unlink (lock);
 		dec_lock_count ();
 		return 1;
@@ -893,7 +894,7 @@ static int write_all (const struct commonio_db *db)
 
 int commonio_close (struct commonio_db *db)
 {
-	int          errors = 0, r;
+	int          errors = 0;
 	char         buf[1024];
 	struct stat  sb;
 
@@ -926,8 +927,7 @@ int commonio_close (struct commonio_db *db)
 		/*
 		 * Create backup file.
 		 */
-		r = snprintf (buf, sizeof buf, "%s-", db->filename);
-		if (r < 0 || (size_t)r >= sizeof buf) {
+		if (SNPRINTF(buf, "%s-", db->filename) == -1) {
 			(void) fclose (db->fp);
 			db->fp = NULL;
 			goto fail;
@@ -964,8 +964,7 @@ int commonio_close (struct commonio_db *db)
 		sb.st_gid = db->st_gid;
 	}
 
-	r = snprintf (buf, sizeof buf, "%s+", db->filename);
-	if (r < 0 || (size_t)r >= sizeof buf)
+	if (SNPRINTF(buf, "%s+", db->filename) == -1)
 		goto fail;
 
 #ifdef WITH_SELINUX

lib/env.c

@@ -166,9 +166,9 @@ void addenv (const char *string, /*@null@*/const char *value)
  */
 void set_env (int argc, char *const *argv)
 {
-	int noname = 1;
-	char variable[1024];
-	char *cp;
+	int   noname = 1;
+	char  variable[1024];
+	char  *cp;
 
 	for (; argc > 0; argc--, argv++) {
 		if (strlen (*argv) >= sizeof variable) {
@@ -177,9 +177,7 @@ void set_env (int argc, char *const *argv)
 
 		cp = strchr (*argv, '=');
 		if (NULL == cp) {
-			int wlen;
-			wlen = snprintf (variable, sizeof variable, "L%d", noname);
-			assert (wlen < (int) sizeof(variable));
+			assert(SNPRINTF(variable, "L%d", noname) != -1);
 			noname++;
 			addenv (variable, *argv);
 		} else {

lib/get_pid.c

@@ -14,6 +14,9 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
+#include "string/sprintf.h"
+
+
 int get_pid (const char *pidstr, pid_t *pid)
 {
 	long long  val;
@@ -76,7 +79,6 @@ int get_pidfd_from_fd(const char *pidfdstr)
 int open_pidfd(const char *pidstr)
 {
 	int    proc_dir_fd;
-	int    written;
 	char   proc_dir_name[32];
 	pid_t  target;
 
@@ -84,9 +86,7 @@ int open_pidfd(const char *pidstr)
 		return -ENOENT;
 
 	/* max string length is 6 + 10 + 1 + 1 = 18, allocate 32 bytes */
-	written = snprintf(proc_dir_name, sizeof(proc_dir_name), "/proc/%u/",
-		target);
-	if ((written <= 0) || ((size_t)written >= sizeof(proc_dir_name))) {
+	if (SNPRINTF(proc_dir_name, "/proc/%u/", target) == -1) {
 		fprintf(stderr, "snprintf of proc path failed for %u: %s\n",
 			target, strerror(errno));
 		return -EINVAL;

lib/hushed.c

@@ -18,6 +18,9 @@
 #include "defines.h"
 #include "prototypes.h"
 #include "getdef.h"
+#include "string/sprintf.h"
+
+
 /*
  * hushed - determine if a user receives login messages
  *
@@ -26,11 +29,11 @@
  */
 bool hushed (const char *username)
 {
-	struct passwd *pw;
-	const char *hushfile;
-	char buf[BUFSIZ];
-	bool found;
-	FILE *fp;
+	bool           found;
+	char           buf[BUFSIZ];
+	FILE           *fp;
+	const char     *hushfile;
+	struct passwd  *pw;
 
 	/*
 	 * Get the name of the file to use.  If this option is not
@@ -53,7 +56,7 @@ bool hushed (const char *username)
 	 */
 
 	if (hushfile[0] != '/') {
-		(void) snprintf (buf, sizeof (buf), "%s/%s", pw->pw_dir, hushfile);
+		SNPRINTF(buf, "%s/%s", pw->pw_dir, hushfile);
 		return (access (buf, F_OK) == 0);
 	}
 

lib/nss.c

@@ -14,6 +14,8 @@
 #include "../libsubid/subid.h"
 #include "shadowlog_internal.h"
 #include "shadowlog.h"
+#include "string/sprintf.h"
+
 
 #define NSSWITCH "/etc/nsswitch.conf"
 
@@ -45,7 +47,7 @@ static void nss_exit(void) {
 // nsswitch_path is an argument only to support testing.
 void nss_init(const char *nsswitch_path) {
 	char    *line = NULL, *p, *token, *saveptr;
-	char    libname[65];
+	char    libname[64];
 	FILE    *nssfp = NULL;
 	FILE    *shadow_logfd = log_get_logfd();
 	void    *h;
@@ -103,7 +105,7 @@ void nss_init(const char *nsswitch_path) {
 		fprintf(shadow_logfd, "Using files\n");
 		goto null_subid;
 	}
-	snprintf(libname, 64,  "libsubid_%s.so", token);
+	SNPRINTF(libname, "libsubid_%s.so", token);
 	h = dlopen(libname, RTLD_LAZY);
 	if (!h) {
 		fprintf(shadow_logfd, "Error opening %s: %s\n", libname, dlerror());

lib/pwauth.c

@@ -25,6 +25,7 @@
 #include "prototypes.h"
 #include "pwauth.h"
 #include "getdef.h"
+#include "string/sprintf.h"
 
 #ifdef SKEY
 #include <skey.h>
@@ -51,16 +52,16 @@ int pw_auth (const char *cipher,
              int reason,
              /*@null@*/const char *input)
 {
-	char prompt[1024];
-	char *clear = NULL;
-	const char *cp;
-	const char *encrypted;
-	int retval;
+	int          retval;
+	char         prompt[1024];
+	char         *clear = NULL;
+	const char   *cp;
+	const char   *encrypted;
 
 #ifdef	SKEY
-	bool use_skey = false;
-	char challenge_info[40];
-	struct skey skey;
+	bool         use_skey = false;
+	char         challenge_info[40];
+	struct skey  skey;
 #endif
 
 	/*
@@ -141,7 +142,7 @@ int pw_auth (const char *cipher,
 		}
 #endif
 
-		snprintf (prompt, sizeof prompt, cp, user);
+		SNPRINTF(prompt, cp, user);
 		clear = agetpass(prompt);
 		input = (clear == NULL) ? "" : clear;
 	}

lib/shell.c

@@ -15,6 +15,9 @@
 #include <errno.h>
 #include "prototypes.h"
 #include "defines.h"
+#include "string/sprintf.h"
+
+
 extern char **newenvp;
 extern size_t newenvc;
 
@@ -45,7 +48,7 @@ int shell (const char *file, /*@null@*/const char *arg, char *const envp[])
 	 * don't want to tell us what it is themselves.
 	 */
 	if (arg == NULL) {
-		snprintf(arg0, sizeof(arg0), "-%s", Basename(file));
+		SNPRINTF(arg0, "-%s", Basename(file));
 		arg = arg0;
 	}
 
@@ -71,7 +74,7 @@ int shell (const char *file, /*@null@*/const char *arg, char *const envp[])
 	 * how to execute this stupid shell, so I might as well give
 	 * up in disgust ...
 	 */
-	(void) snprintf (arg0, sizeof arg0, _("Cannot execute %s"), file);
+	SNPRINTF(arg0, _("Cannot execute %s"), file);
 	errno = err;
 	perror (arg0);
 	return err;

lib/subordinateio.c

@@ -18,6 +18,8 @@
 #include <fcntl.h>
 
 #include "alloc.h"
+#include "string/sprintf.h"
+
 
 #define ID_SIZE 31
 
@@ -220,10 +222,9 @@ static const struct subordinate_range *find_range(struct commonio_db *db,
          * (It may be specified as literal UID or as another username which
          * has the same UID as the username we are looking for.)
          */
-        struct passwd *pwd;
-        uid_t          owner_uid;
         char           owner_uid_string[33];
-        int ret;
+        uid_t          owner_uid;
+        struct passwd  *pwd;
 
 
         /* Get UID of the username we are looking for */
@@ -233,8 +234,7 @@ static const struct subordinate_range *find_range(struct commonio_db *db,
                 return NULL;
         }
         owner_uid = pwd->pw_uid;
-        ret = snprintf(owner_uid_string, sizeof (owner_uid_string), "%lu", (unsigned long)owner_uid);
-        if (ret < 0 || (size_t)ret >= sizeof (owner_uid_string))
+        if (SNPRINTF(owner_uid_string, "%lu", (unsigned long) owner_uid) == -1)
                 return NULL;
 
         commonio_rewind(db);

lib/user_busy.c

@@ -23,6 +23,8 @@
 #include "subordinateio.h"
 #endif				/* ENABLE_SUBIDS */
 #include "shadowlog.h"
+#include "string/sprintf.h"
+
 
 #ifdef __linux__
 static int check_status (const char *name, const char *sname, uid_t uid);
@@ -83,11 +85,11 @@ static int user_busy_utmp (const char *name)
 static int different_namespace (const char *sname)
 {
 	/* 41: /proc/xxxxxxxxxx/task/xxxxxxxxxx/ns/user + \0 */
-	char path[41];
-	char buf[512], buf2[512];
-	ssize_t llen1, llen2;
+	char     path[41];
+	char     buf[512], buf2[512];
+	ssize_t  llen1, llen2;
 
-	snprintf (path, 41, "/proc/%s/ns/user", sname);
+	SNPRINTF(path, "/proc/%s/ns/user", sname);
 
 	if ((llen1 = readlink (path, buf, sizeof(buf))) == -1)
 		return 0;
@@ -106,11 +108,11 @@ static int different_namespace (const char *sname)
 static int check_status (const char *name, const char *sname, uid_t uid)
 {
 	/* 40: /proc/xxxxxxxxxx/task/xxxxxxxxxx/status + \0 */
-	char status[40];
-	char line[1024];
-	FILE *sfile;
+	char  status[40];
+	char  line[1024];
+	FILE  *sfile;
 
-	snprintf (status, 40, "/proc/%s/status", sname);
+	SNPRINTF(status, "/proc/%s/status", sname);
 
 	sfile = fopen (status, "r");
 	if (NULL == sfile) {
@@ -205,7 +207,7 @@ static int user_busy_processes (const char *name, uid_t uid)
 		}
 
 		/* Check if the process is in our chroot */
-		snprintf(root_path, sizeof(root_path), "/proc/%lu/root", (unsigned long) pid);
+		SNPRINTF(root_path, "/proc/%lu/root", (unsigned long) pid);
 		if (stat (root_path, &sbroot_process) != 0) {
 			continue;
 		}
@@ -225,7 +227,7 @@ static int user_busy_processes (const char *name, uid_t uid)
 			return 1;
 		}
 
-		snprintf(task_path, sizeof(task_path), "/proc/%lu/task", (unsigned long) pid);
+		SNPRINTF(task_path, "/proc/%lu/task", (unsigned long) pid);
 		task_dir = opendir (task_path);
 		if (task_dir != NULL) {
 			while ((ent = readdir (task_dir)) != NULL) {