From: Todd C. Miller <Todd.Miller@courtesan.com>
Date: Thu, 15 Aug 2013 20:09:53 +0000 (-0600)
Subject: Add support to the debug subsystem for zero-length strings.  This
X-Git-Tag: SUDO_1_8_8^2~55
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=bec394dc11e29f2b34206ff1fab01ea46f589d13;p=sudo

Add support to the debug subsystem for zero-length strings.  This
can happen for things like warning(NULL) or fatal(NULL) where we
just want to log the errno string.
---

diff --git a/common/sudo_debug.c b/common/sudo_debug.c
index c46bf3634..d5c356fa8 100644
--- a/common/sudo_debug.c
+++ b/common/sudo_debug.c
@@ -155,8 +155,14 @@ int sudo_debug_init(const char *debugfile, const char *settings)
 	sudo_debug_mode = SUDO_DEBUG_MODE_CONV;
     }
 
+    /* Stash the pid string so we only have to format it once. */
+    (void)snprintf(sudo_debug_pidstr, sizeof(sudo_debug_pidstr), "[%d] ",
+	(int)getpid());
+    sudo_debug_pidlen = strlen(sudo_debug_pidstr);
+
     /* Parse settings string. */
-    buf = estrdup(settings);
+    if ((buf = strdup(settings)) == NULL)
+	return 0;
     for ((cp = strtok(buf, ",")); cp != NULL; (cp = strtok(NULL, ","))) {
 	/* Should be in the form subsys@pri. */
 	subsys = cp;
@@ -181,11 +187,7 @@ int sudo_debug_init(const char *debugfile, const char *settings)
 	    }
 	}
     }
-    efree(buf);
-
-    (void)snprintf(sudo_debug_pidstr, sizeof(sudo_debug_pidstr), "[%d] ",
-	(int)getpid());
-    sudo_debug_pidlen = strlen(sudo_debug_pidstr);
+    free(buf);
 
     return 1;
 }
@@ -212,28 +214,32 @@ sudo_debug_enter(const char *func, const char *file, int line,
 	"-> %s @ %s:%d", func, file, line);
 }
 
-void sudo_debug_exit(const char *func, const char *file, int line,
+void
+sudo_debug_exit(const char *func, const char *file, int line,
     int subsys)
 {
     sudo_debug_printf2(NULL, NULL, 0, subsys | SUDO_DEBUG_TRACE,
 	"<- %s @ %s:%d", func, file, line);
 }
 
-void sudo_debug_exit_int(const char *func, const char *file, int line,
+void
+sudo_debug_exit_int(const char *func, const char *file, int line,
     int subsys, int rval)
 {
     sudo_debug_printf2(NULL, NULL, 0, subsys | SUDO_DEBUG_TRACE,
 	"<- %s @ %s:%d := %d", func, file, line, rval);
 }
 
-void sudo_debug_exit_long(const char *func, const char *file, int line,
+void
+sudo_debug_exit_long(const char *func, const char *file, int line,
     int subsys, long rval)
 {
     sudo_debug_printf2(NULL, NULL, 0, subsys | SUDO_DEBUG_TRACE,
 	"<- %s @ %s:%d := %ld", func, file, line, rval);
 }
 
-void sudo_debug_exit_size_t(const char *func, const char *file, int line,
+void
+sudo_debug_exit_size_t(const char *func, const char *file, int line,
     int subsys, size_t rval)
 {
     /* XXX - should use %zu but our snprintf.c doesn't support it */
@@ -242,7 +248,8 @@ void sudo_debug_exit_size_t(const char *func, const char *file, int line,
 }
 
 /* We use int, not bool, here for functions that return -1 on error. */
-void sudo_debug_exit_bool(const char *func, const char *file, int line,
+void
+sudo_debug_exit_bool(const char *func, const char *file, int line,
     int subsys, int rval)
 {
     if (rval == true || rval == false) {
@@ -254,14 +261,16 @@ void sudo_debug_exit_bool(const char *func, const char *file, int line,
     }
 }
 
-void sudo_debug_exit_str(const char *func, const char *file, int line,
+void
+sudo_debug_exit_str(const char *func, const char *file, int line,
     int subsys, const char *rval)
 {
     sudo_debug_printf2(NULL, NULL, 0, subsys | SUDO_DEBUG_TRACE,
 	"<- %s @ %s:%d := %s", func, file, line, rval ? rval : "(null)");
 }
 
-void sudo_debug_exit_str_masked(const char *func, const char *file, int line,
+void
+sudo_debug_exit_str_masked(const char *func, const char *file, int line,
     int subsys, const char *rval)
 {
     static const char stars[] = "********************************************************************************";
@@ -271,7 +280,8 @@ void sudo_debug_exit_str_masked(const char *func, const char *file, int line,
 	"<- %s @ %s:%d := %.*s", func, file, line, len, rval ? stars : "(null)");
 }
 
-void sudo_debug_exit_ptr(const char *func, const char *file, int line,
+void
+sudo_debug_exit_ptr(const char *func, const char *file, int line,
     int subsys, const void *rval)
 {
     sudo_debug_printf2(NULL, NULL, 0, subsys | SUDO_DEBUG_TRACE,
@@ -282,24 +292,34 @@ static void
 sudo_debug_write_conv(const char *func, const char *file, int lineno,
     const char *str, int len, int errno_val)
 {
-    /* Remove the newline at the end if appending extra info. */
-    if (str[len - 1] == '\n')
+    /* Remove trailing newlines. */
+    while (len > 0 && str[len - 1] == '\n')
 	len--;
 
-    if (func != NULL && file != NULL) {
-	if (errno_val) {
-	    sudo_printf(SUDO_CONV_DEBUG_MSG, "%.*s: %s @ %s() %s:%d",
-		len, str, strerror(errno_val), func, file, lineno);
+    if (len > 0) {
+	if (func != NULL && file != NULL) {
+	    if (errno_val) {
+		sudo_printf(SUDO_CONV_DEBUG_MSG, "%.*s: %s @ %s() %s:%d",
+		    len, str, strerror(errno_val), func, file, lineno);
+	    } else {
+		sudo_printf(SUDO_CONV_DEBUG_MSG, "%.*s @ %s() %s:%d",
+		    len, str, func, file, lineno);
+	    }
 	} else {
-	    sudo_printf(SUDO_CONV_DEBUG_MSG, "%.*s @ %s() %s:%d",
-		len, str, func, file, lineno);
+	    if (errno_val) {
+		sudo_printf(SUDO_CONV_DEBUG_MSG, "%.*s: %s",
+		    len, str, strerror(errno_val));
+	    } else {
+		sudo_printf(SUDO_CONV_DEBUG_MSG, "%.*s", len, str);
+	    }
 	}
-    } else {
-	if (errno_val) {
-	    sudo_printf(SUDO_CONV_DEBUG_MSG, "%.*s: %s",
-		len, str, strerror(errno_val));
+    } else if (errno_val) {
+	/* Only print error string. */
+	if (func != NULL && file != NULL) {
+	    sudo_printf(SUDO_CONV_DEBUG_MSG, "%s @ %s() %s:%d",
+		strerror(errno_val), func, file, lineno);
 	} else {
-	    sudo_printf(SUDO_CONV_DEBUG_MSG, "%.*s", len, str);
+	    sudo_printf(SUDO_CONV_DEBUG_MSG, "%s", strerror(errno_val));
 	}
     }
 }
@@ -311,8 +331,7 @@ sudo_debug_write_file(const char *func, const char *file, int lineno,
     char *timestr, numbuf[(((sizeof(int) * 8) + 2) / 3) + 2];
     time_t now;
     struct iovec iov[12];
-    int iovcnt = 4;
-    bool need_newline = false;
+    int iovcnt = 3;
 
     /* Prepend program name and pid with a trailing space. */
     iov[1].iov_base = (char *)getprogname();
@@ -321,25 +340,24 @@ sudo_debug_write_file(const char *func, const char *file, int lineno,
     iov[2].iov_len = sudo_debug_pidlen;
 
     /* Add string along with newline if it doesn't have one. */
-    iov[3].iov_base = (char *)str;
-    iov[3].iov_len = len;
-    if (str[len - 1] != '\n')
-	need_newline = true;
+    if (len > 0) {
+	iov[iovcnt].iov_base = (char *)str;
+	iov[iovcnt].iov_len = len;
+	while (len > 0 && str[len - 1] == '\n')
+	    iov[iovcnt].iov_len--;
+	iovcnt++;
+    }
 
     /* Append error string if errno is specified. */
     if (errno_val) {
-	iov[iovcnt].iov_base = ": ";
-	iov[iovcnt].iov_len = 2;
-	iovcnt++;
+	if (len > 0) {
+	    iov[iovcnt].iov_base = ": ";
+	    iov[iovcnt].iov_len = 2;
+	    iovcnt++;
+	}
 	iov[iovcnt].iov_base = strerror(errno_val);
 	iov[iovcnt].iov_len = strlen(iov[iovcnt].iov_base);
 	iovcnt++;
-
-	/* Move newline to the end. */
-	if (!need_newline) {
-	    need_newline = true;
-	    iov[3].iov_len--;
-	}
     }
 
     /* If function, file and lineno are specified, append them. */
@@ -364,21 +382,12 @@ sudo_debug_write_file(const char *func, const char *file, int lineno,
 	iov[iovcnt].iov_base = numbuf;
 	iov[iovcnt].iov_len = strlen(numbuf);
 	iovcnt++;
-
-	/* Move newline to the end. */
-	if (!need_newline) {
-	    need_newline = true;
-	    iov[3].iov_len--;
-	}
     }
 
-    /* Append newline as needed. */
-    if (need_newline) {
-	/* force newline */
-	iov[iovcnt].iov_base = "\n";
-	iov[iovcnt].iov_len = 1;
-	iovcnt++;
-    }
+    /* Append newline. */
+    iov[iovcnt].iov_base = "\n";
+    iov[iovcnt].iov_len = 1;
+    iovcnt++;
 
     /* Do timestamp last due to ctime's static buffer. */
     time(&now);
@@ -396,9 +405,6 @@ void
 sudo_debug_write2(const char *func, const char *file, int lineno,
     const char *str, int len, int errno_val)
 {
-    if (len <= 0)
-	return;
-
     switch (sudo_debug_mode) {
     case SUDO_DEBUG_MODE_CONV:
 	sudo_debug_write_conv(func, file, lineno, str, len, errno_val);
@@ -421,7 +427,7 @@ sudo_debug_vprintf2(const char *func, const char *file, int lineno, int level,
     const char *fmt, va_list ap)
 {
     int buflen, pri, subsys, saved_errno = errno;
-    char *buf;
+    char *buf = NULL;
 
     if (!sudo_debug_mode)
 	return;
@@ -432,8 +438,7 @@ sudo_debug_vprintf2(const char *func, const char *file, int lineno, int level,
 
     /* Make sure we want debug info at this level. */
     if (subsys < NUM_SUBSYSTEMS && sudo_debug_settings[subsys] >= pri) {
-	buflen = vasprintf(&buf, fmt, ap);
-	va_end(ap);
+	buflen = fmt ? vasprintf(&buf, fmt, ap) : 0;
 	if (buflen != -1) {
 	    int errcode = ISSET(level, SUDO_DEBUG_ERRNO) ? saved_errno : 0;
 	    if (ISSET(level, SUDO_DEBUG_LINENO))
diff --git a/include/sudo_debug.h b/include/sudo_debug.h
index ed1cd7147..ccc80ea5d 100644
--- a/include/sudo_debug.h
+++ b/include/sudo_debug.h
@@ -201,8 +201,8 @@ void sudo_debug_exit_str_masked(const char *func, const char *file, int line, in
 void sudo_debug_exit_ptr(const char *func, const char *file, int line, int subsys, const void *rval);
 int sudo_debug_fd_set(int fd);
 int sudo_debug_init(const char *debugfile, const char *settings);
-void sudo_debug_printf2(const char *func, const char *file, int line, int level, const char *fmt, ...) __printflike(5, 6);
-void sudo_debug_vprintf2(const char *func, const char *file, int line, int level, const char *fmt, va_list ap);
+void sudo_debug_printf2(const char *func, const char *file, int line, int level, const char *fmt, ...) __printf0like(5, 6);
+void sudo_debug_vprintf2(const char *func, const char *file, int line, int level, const char *fmt, va_list ap) __printf0like(5, 0);
 void sudo_debug_write(const char *str, int len, int errno_val);
 void sudo_debug_write2(const char *func, const char *file, int line, const char *str, int len, int errno_val);
 pid_t sudo_debug_fork(void);