libpam: move line assembling functions to header

This follows the idiom of debug functions which reside in headers to
allow their usage within libpam itself and its modules without adding
modutil functions, i.e. extending the API.

No functional change.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>

3 files changed, 264 insertions, 253 deletions

diff --git a/libpam/Makefile.am b/libpam/Makefile.am
index 0d2fb6f3..5ed045a6 100644
--- a/libpam/Makefile.am
+++ b/libpam/Makefile.am
@@ -18,8 +18,9 @@ include_HEADERS = include/security/_pam_compat.h \
 	include/security/pam_ext.h include/security/pam_modutil.h
 
 noinst_HEADERS = pam_prelude.h pam_private.h pam_tokens.h \
-		pam_modutil_private.h include/pam_cc_compat.h \
-		include/pam_inline.h include/test_assert.h
+		pam_modutil_private.h include/pam_assemble_line.h \
+		include/pam_cc_compat.h include/pam_inline.h \
+		include/test_assert.h
 
 libpam_la_LDFLAGS = -no-undefined -version-info 85:1:85
 libpam_la_LIBADD = @LIBAUDIT@ $(LIBPRELUDE_LIBS) $(ECONF_LIBS) @LIBDL@ @LTLIBINTL@
diff --git a/libpam/include/pam_assemble_line.h b/libpam/include/pam_assemble_line.h
new file mode 100644
index 00000000..a460b9e1
--- /dev/null
+++ b/libpam/include/pam_assemble_line.h
@@ -0,0 +1,259 @@
+/* pam_assemble_line.h -- routine to parse configuration lines */
+
+#ifndef PAM_ASSEMBLE_LINE_H
+#define PAM_ASSEMBLE_LINE_H
+
+#include "pam_inline.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+struct line_buffer {
+	char *assembled;
+	char *chunk;
+	size_t chunk_size;
+	size_t len;
+	size_t size;
+};
+
+static int _pam_buffer_add(struct line_buffer *buffer, char *start, char *end)
+{
+    size_t len = end - start;
+
+    D(("assembled: [%zu/%zu] '%s', adding [%zu] '%s'",
+	buffer->len, buffer->size,
+	buffer->assembled == NULL ? "" : buffer->assembled, len, start));
+
+    if (start == end)
+	return 0;
+
+    if (buffer->assembled == NULL && buffer->chunk == start) {
+	/* no extra allocation needed, just move chunk to assembled */
+	buffer->assembled = buffer->chunk;
+	buffer->len = len;
+	buffer->size = buffer->chunk_size;
+
+	buffer->chunk = NULL;
+	buffer->chunk_size = 0;
+
+	D(("exiting with quick exchange"));
+	return 0;
+    }
+
+    if (buffer->len + len + 1 > buffer->size) {
+	size_t size;
+	char *p;
+
+	size = buffer->len + len + 1;
+	if ((p = realloc(buffer->assembled, size)) == NULL)
+		return -1;
+
+	buffer->assembled = p;
+	buffer->size = size;
+    }
+
+    memcpy(buffer->assembled + buffer->len, start, len);
+    buffer->len += len;
+    buffer->assembled[buffer->len] = '\0';
+
+    D(("exiting"));
+    return 0;
+}
+
+static inline int _pam_buffer_add_eol(struct line_buffer *buffer,
+				      char *start, char *end)
+{
+    if (buffer->assembled != NULL || (*start != '\0' && *start != '\n'))
+	return _pam_buffer_add(buffer, start, end);
+    return 0;
+}
+
+static void _pam_buffer_clear(struct line_buffer *buffer)
+{
+    _pam_drop(buffer->assembled);
+    _pam_drop(buffer->chunk);
+    buffer->chunk_size = 0;
+    buffer->len = 0;
+    buffer->size = 0;
+}
+
+static void _pam_buffer_init(struct line_buffer *buffer)
+{
+    buffer->assembled = NULL;
+    buffer->chunk = NULL;
+    _pam_buffer_clear(buffer);
+}
+
+static void _pam_buffer_purge(struct line_buffer *buffer)
+{
+    _pam_drop(buffer->chunk);
+    buffer->chunk_size = 0;
+}
+
+static void _pam_buffer_shift(struct line_buffer *buffer)
+{
+    if (buffer->assembled == NULL)
+	return;
+
+    _pam_buffer_purge(buffer);
+    buffer->chunk = buffer->assembled;
+    buffer->chunk_size = buffer->size;
+
+    buffer->assembled = NULL;
+    buffer->size = 0;
+    buffer->len = 0;
+}
+
+static inline int _pam_buffer_valid(struct line_buffer *buffer)
+{
+    return buffer->assembled != NULL && *buffer->assembled != '\0';
+}
+
+/*
+ * Trim string to relevant parts of a configuration line.
+ *
+ * Preceding whitespaces are skipped and comment (#) marks the end of
+ * configuration line.
+ *
+ * Returns start of configuration line.
+ */
+static inline char *_pam_str_trim(char *str)
+{
+    /* skip leading spaces */
+    str += strspn(str, " \t");
+    /*
+     * we are only interested in characters before the first '#'
+     * character
+     */
+    str[strcspn(str, "#")] = '\0';
+
+    return str;
+}
+
+/*
+ * Remove escaped newline from end of string.
+ *
+ * Configuration lines may span across multiple lines in a file
+ * by ending a line with a backslash (\).
+ *
+ * If an escaped newline is encountered, the backslash will be
+ * replaced with a blank ' ' and the newline itself removed.
+ * Then the variable "end" will point to the new end of line.
+ *
+ * Returns 0 if escaped newline was found and replaced, 1 otherwise.
+ */
+static inline int _pam_str_unescnl(char *start, char **end)
+{
+    int ret = 1;
+    char *p = *end;
+
+    /*
+     * Check for backslash by scanning back from the end of
+     * the entered line, the '\n' should be included since
+     * normally a line is terminated with this character.
+     */
+    while (p > start && ((*--p == ' ') || (*p == '\t') || (*p == '\n')))
+	;
+    if (*p == '\\') {
+	*p++ = ' ';         /* replace backslash with ' ' */
+	*p = '\0';          /* truncate the line here */
+	*end = p;
+	ret = 0;
+    }
+
+    return ret;
+}
+
+/*
+ * Prepare line from file for configuration line parsing.
+ *
+ * A configuration line may span across multiple lines in a file.
+ * Remove comments and skip preceding whitespaces.
+ *
+ * Returns 0 if line spans across multiple lines, 1 if
+ * end of line is encountered.
+ */
+static inline int _pam_str_prepare(char *line, ssize_t len,
+				   char **start, char **end)
+{
+    int ret;
+
+    *start = line;
+    *end = line + len;
+
+    ret = _pam_str_unescnl(*start, end) || strchr(*start, '#') != NULL;
+
+    *start = _pam_str_trim(*start);
+
+    return ret;
+}
+
+/*
+ * This is where we read a line of the PAM config file. The line may be
+ * preceded by lines of comments and also extended with "\\\n"
+ *
+ * Returns 0 on EOF, 1 on successful line parsing, or -1 on error.
+ */
+
+static int _pam_assemble_line(FILE *f, struct line_buffer *buffer)
+{
+    int ret = 0;
+
+    /* loop broken with a 'break' when a non-'\\n' ended line is read */
+
+    D(("called."));
+
+    _pam_buffer_shift(buffer);
+
+    for (;;) {
+	char *start, *end;
+	ssize_t n;
+	int eol;
+
+	if ((n = getline(&buffer->chunk, &buffer->chunk_size, f)) == -1) {
+	    if (ret) {
+		/* Incomplete read */
+		ret = -1;
+	    } else {
+		/* EOF */
+		ret = 0;
+	    }
+	    break;
+	}
+
+	eol = _pam_str_prepare(buffer->chunk, n, &start, &end);
+
+	if (eol) {
+	    if (_pam_buffer_add_eol(buffer, start, end)) {
+		ret = -1;
+		break;
+	    }
+	    if (_pam_buffer_valid(buffer)) {
+		/* Successfully parsed a line */
+		ret = 1;
+		break;
+	    }
+	    /* Start parsing next line */
+	    _pam_buffer_shift(buffer);
+	    ret = 0;
+	} else {
+	    /* Configuration line spans across multiple lines in file */
+	    if (_pam_buffer_add(buffer, start, end)) {
+		ret = -1;
+		break;
+	    }
+	    /* Keep parsing line */
+	    ret = 1;
+	}
+    }
+
+    if (ret == 1)
+	_pam_buffer_purge(buffer);
+    else
+	_pam_buffer_clear(buffer);
+
+    return ret;
+}
+
+#endif /* PAM_ASSEMBLE_LINE_H */
diff --git a/libpam/pam_handlers.c b/libpam/pam_handlers.c
index 88e12253..28f82d73 100644
--- a/libpam/pam_handlers.c
+++ b/libpam/pam_handlers.c
@@ -18,24 +18,14 @@
 #include <fcntl.h>
 #include <unistd.h>
 
+#include "pam_assemble_line.h"
+
 #define MODULE_CHUNK              4
 #define UNKNOWN_MODULE       "<*unknown module*>"
 #ifndef _PAM_ISA
 #define _PAM_ISA "."
 #endif
 
-struct line_buffer {
-	char *assembled;
-	char *chunk;
-	size_t chunk_size;
-	size_t len;
-	size_t size;
-};
-
-static void _pam_buffer_init(struct line_buffer *buffer);
-
-static int _pam_assemble_line(FILE *f, struct line_buffer *buf);
-
 static void _pam_free_handlers_aux(struct handler **hp);
 
 static int _pam_add_handler(pam_handle_t *pamh
@@ -584,245 +574,6 @@ int _pam_init_handlers(pam_handle_t *pamh)
     return PAM_SUCCESS;
 }
 
-static int _pam_buffer_add(struct line_buffer *buffer, char *start, char *end)
-{
-    size_t len = end - start;
-
-    D(("assembled: [%zu/%zu] '%s', adding [%zu] '%s'",
-	buffer->len, buffer->size,
-	buffer->assembled == NULL ? "" : buffer->assembled, len, start));
-
-    if (start == end)
-	return 0;
-
-    if (buffer->assembled == NULL && buffer->chunk == start) {
-	/* no extra allocation needed, just move chunk to assembled */
-	buffer->assembled = buffer->chunk;
-	buffer->len = len;
-	buffer->size = buffer->chunk_size;
-
-	buffer->chunk = NULL;
-	buffer->chunk_size = 0;
-
-	D(("exiting with quick exchange"));
-	return 0;
-    }
-
-    if (buffer->len + len + 1 > buffer->size) {
-	size_t size;
-	char *p;
-
-	size = buffer->len + len + 1;
-	if ((p = realloc(buffer->assembled, size)) == NULL)
-		return -1;
-
-	buffer->assembled = p;
-	buffer->size = size;
-    }
-
-    memcpy(buffer->assembled + buffer->len, start, len);
-    buffer->len += len;
-    buffer->assembled[buffer->len] = '\0';
-
-    D(("exiting"));
-    return 0;
-}
-
-static inline int _pam_buffer_add_eol(struct line_buffer *buffer,
-				      char *start, char *end)
-{
-    if (buffer->assembled != NULL || (*start != '\0' && *start != '\n'))
-	return _pam_buffer_add(buffer, start, end);
-    return 0;
-}
-
-static void _pam_buffer_clear(struct line_buffer *buffer)
-{
-    _pam_drop(buffer->assembled);
-    _pam_drop(buffer->chunk);
-    buffer->chunk_size = 0;
-    buffer->len = 0;
-    buffer->size = 0;
-}
-
-static void _pam_buffer_init(struct line_buffer *buffer)
-{
-    buffer->assembled = NULL;
-    buffer->chunk = NULL;
-    _pam_buffer_clear(buffer);
-}
-
-static void _pam_buffer_purge(struct line_buffer *buffer)
-{
-    _pam_drop(buffer->chunk);
-    buffer->chunk_size = 0;
-}
-
-static void _pam_buffer_shift(struct line_buffer *buffer)
-{
-    if (buffer->assembled == NULL)
-	return;
-
-    _pam_buffer_purge(buffer);
-    buffer->chunk = buffer->assembled;
-    buffer->chunk_size = buffer->size;
-
-    buffer->assembled = NULL;
-    buffer->size = 0;
-    buffer->len = 0;
-}
-
-static inline int _pam_buffer_valid(struct line_buffer *buffer)
-{
-    return buffer->assembled != NULL && *buffer->assembled != '\0';
-}
-
-/*
- * Trim string to relevant parts of a configuration line.
- *
- * Preceding whitespaces are skipped and comment (#) marks the end of
- * configuration line.
- *
- * Returns start of configuration line.
- */
-static inline char *_pam_str_trim(char *str)
-{
-    /* skip leading spaces */
-    str += strspn(str, " \t");
-    /*
-     * we are only interested in characters before the first '#'
-     * character
-     */
-    str[strcspn(str, "#")] = '\0';
-
-    return str;
-}
-
-/*
- * Remove escaped newline from end of string.
- *
- * Configuration lines may span across multiple lines in a file
- * by ending a line with a backslash (\).
- *
- * If an escaped newline is encountered, the backslash will be
- * replaced with a blank ' ' and the newline itself removed.
- * Then the variable "end" will point to the new end of line.
- *
- * Returns 0 if escaped newline was found and replaced, 1 otherwise.
- */
-static inline int _pam_str_unescnl(char *start, char **end)
-{
-    int ret = 1;
-    char *p = *end;
-
-    /*
-     * Check for backslash by scanning back from the end of
-     * the entered line, the '\n' should be included since
-     * normally a line is terminated with this character.
-     */
-    while (p > start && ((*--p == ' ') || (*p == '\t') || (*p == '\n')))
-	;
-    if (*p == '\\') {
-	*p++ = ' ';         /* replace backslash with ' ' */
-	*p = '\0';          /* truncate the line here */
-	*end = p;
-	ret = 0;
-    }
-
-    return ret;
-}
-
-/*
- * Prepare line from file for configuration line parsing.
- *
- * A configuration line may span across multiple lines in a file.
- * Remove comments and skip preceding whitespaces.
- *
- * Returns 0 if line spans across multiple lines, 1 if
- * end of line is encountered.
- */
-static inline int _pam_str_prepare(char *line, ssize_t len,
-				   char **start, char **end)
-{
-    int ret;
-
-    *start = line;
-    *end = line + len;
-
-    ret = _pam_str_unescnl(*start, end) || strchr(*start, '#') != NULL;
-
-    *start = _pam_str_trim(*start);
-
-    return ret;
-}
-
-/*
- * This is where we read a line of the PAM config file. The line may be
- * preceded by lines of comments and also extended with "\\\n"
- *
- * Returns 0 on EOF, 1 on successful line parsing, or -1 on error.
- */
-
-static int _pam_assemble_line(FILE *f, struct line_buffer *buffer)
-{
-    int ret = 0;
-
-    /* loop broken with a 'break' when a non-'\\n' ended line is read */
-
-    D(("called."));
-
-    _pam_buffer_shift(buffer);
-
-    for (;;) {
-	char *start, *end;
-	ssize_t n;
-	int eol;
-
-	if ((n = getline(&buffer->chunk, &buffer->chunk_size, f)) == -1) {
-	    if (ret) {
-		/* Incomplete read */
-		ret = -1;
-	    } else {
-		/* EOF */
-		ret = 0;
-	    }
-	    break;
-	}
-
-	eol = _pam_str_prepare(buffer->chunk, n, &start, &end);
-
-	if (eol) {
-	    if (_pam_buffer_add_eol(buffer, start, end)) {
-		ret = -1;
-		break;
-	    }
-	    if (_pam_buffer_valid(buffer)) {
-		/* Successfully parsed a line */
-		ret = 1;
-		break;
-	    }
-	    /* Start parsing next line */
-	    _pam_buffer_shift(buffer);
-	    ret = 0;
-	} else {
-	    /* Configuration line spans across multiple lines in file */
-	    if (_pam_buffer_add(buffer, start, end)) {
-		ret = -1;
-		break;
-	    }
-	    /* Keep parsing line */
-	    ret = 1;
-	}
-    }
-
-    if (ret == 1)
-	_pam_buffer_purge(buffer);
-    else
-	_pam_buffer_clear(buffer);
-
-    return ret;
-}
-
 static char *
 extract_modulename(const char *mod_path)
 {