svn commit: r335642 - head/usr.sbin/config
Kyle Evans
kevans at FreeBSD.org
Mon Jun 25 17:17:50 UTC 2018
Author: kevans
Date: Mon Jun 25 17:17:47 2018
New Revision: 335642
URL: https://svnweb.freebsd.org/changeset/base/335642
Log:
config(8): Add `envvar` support
envvar allows adding individual environment variables to the kernel's static
environment without the overhead of pulling in a full file. envvar in a
config looks like:
envvar some_var=5
All envvar-provided variables will be added after the env file is processed,
so envvar keys that exist in the previous env will be overwritten by
whatever value is set here in the kernel configuration directly.
As an aside, envvar lines are intentionally tokenized differently from
basically every other line. We used a named state when ENVVAR is encountered
to gobble up the rest of the line, which will later be cleaned and validated
in post-processing by sanitize_envline. This turns out to be the simplest
and cleanest way to allow the flexibility that kenv does while not
compromising on silly hacks.
Reviewed by: ian (also contributor of sanitize_envline rewrite)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D15962
Modified:
head/usr.sbin/config/config.5
head/usr.sbin/config/config.h
head/usr.sbin/config/config.y
head/usr.sbin/config/lang.l
head/usr.sbin/config/main.c
head/usr.sbin/config/mkmakefile.c
Modified: head/usr.sbin/config/config.5
==============================================================================
--- head/usr.sbin/config/config.5 Mon Jun 25 16:42:49 2018 (r335641)
+++ head/usr.sbin/config/config.5 Mon Jun 25 17:17:47 2018 (r335642)
@@ -23,7 +23,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd February 21, 2016
+.Dd June 22, 2018
.Dt CONFIG 5
.Os
.Sh NAME
@@ -124,6 +124,20 @@ the compiled-in environment instead, unless the boot e
This directive is useful for setting kernel tunables in
embedded environments that do not start from
.Xr loader 8 .
+.\" -------- ENVVAR --------
+.Pp
+.It Ic envvar Ar setting
+Specifies an individual environment setting to be added to the kernel's
+compiled-in environment.
+.Ar setting
+must be of the form
+.Dq Va name=value .
+Optional quotes are supported in both name and value.
+All environment variables specified with
+.Ic envvar
+will be set after any
+.Ic env
+files are included.
.\" -------- FILES --------
.Pp
.It Ic files Ar filename
Modified: head/usr.sbin/config/config.h
==============================================================================
--- head/usr.sbin/config/config.h Mon Jun 25 16:42:49 2018 (r335641)
+++ head/usr.sbin/config/config.h Mon Jun 25 17:17:47 2018 (r335642)
@@ -140,6 +140,13 @@ struct opt_list {
SLIST_HEAD(, opt_list) otab;
+struct envvar {
+ char *env_str;
+ STAILQ_ENTRY(envvar) envvar_next;
+};
+
+STAILQ_HEAD(envvar_head, envvar) envvars;
+
struct hint {
char *hint_name;
STAILQ_ENTRY(hint) hint_next;
Modified: head/usr.sbin/config/config.y
==============================================================================
--- head/usr.sbin/config/config.y Mon Jun 25 16:42:49 2018 (r335641)
+++ head/usr.sbin/config/config.y Mon Jun 25 17:17:47 2018 (r335642)
@@ -12,6 +12,7 @@
%token DEVICE
%token NODEVICE
%token ENV
+%token ENVVAR
%token EQUALS
%token PLUSEQUALS
%token HINTS
@@ -26,6 +27,7 @@
%token INCLUDE
%token FILES
+%token <str> ENVLINE
%token <str> ID
%token <val> NUMBER
@@ -193,6 +195,15 @@ Config_spec:
env = $2;
envmode = 1;
} |
+ ENVVAR ENVLINE {
+ struct envvar *envvar;
+
+ envvar = (struct envvar *)calloc(1, sizeof (struct envvar));
+ if (envvar == NULL)
+ err(EXIT_FAILURE, "calloc");
+ envvar->env_str = $2;
+ STAILQ_INSERT_TAIL(&envvars, envvar, envvar_next);
+ } |
HINTS ID {
struct hint *hint;
Modified: head/usr.sbin/config/lang.l
==============================================================================
--- head/usr.sbin/config/lang.l Mon Jun 25 16:42:49 2018 (r335641)
+++ head/usr.sbin/config/lang.l Mon Jun 25 17:17:47 2018 (r335642)
@@ -70,6 +70,7 @@ struct kt {
{ "nodevice", NODEVICE },
{ "nodevices", NODEVICE },
{ "env", ENV },
+ { "envvar", ENVVAR },
{ "hints", HINTS },
{ "ident", IDENT },
{ "machine", ARCH }, /* MACHINE is defined in /sys/param.h */
@@ -105,7 +106,13 @@ int yyerror(const char *);
ID [A-Za-z_][-A-Za-z_0-9]*
PATH [./][-/.%^A-Za-z_0-9]+
%START TOEOL
+%START ENVC
%%
+<ENVC>[^#\n]* {
+ BEGIN 0;
+ yylval.str = strdup(yytext);
+ return ENVLINE;
+ }
{ID} {
int i;
@@ -115,6 +122,9 @@ PATH [./][-/.%^A-Za-z_0-9]+
yylval.str = strdup(yytext);
return ID;
}
+ /* We'll glom onto the rest of an envvar line */
+ if (i == ENVVAR)
+ BEGIN ENVC;
return i;
}
\\\"[^"]+\\\" {
Modified: head/usr.sbin/config/main.c
==============================================================================
--- head/usr.sbin/config/main.c Mon Jun 25 16:42:49 2018 (r335641)
+++ head/usr.sbin/config/main.c Mon Jun 25 17:17:47 2018 (r335642)
@@ -204,6 +204,7 @@ main(int argc, char **argv)
STAILQ_INIT(&fntab);
STAILQ_INIT(&ftab);
STAILQ_INIT(&hints);
+ STAILQ_INIT(&envvars);
if (yyparse())
exit(3);
Modified: head/usr.sbin/config/mkmakefile.c
==============================================================================
--- head/usr.sbin/config/mkmakefile.c Mon Jun 25 16:42:49 2018 (r335641)
+++ head/usr.sbin/config/mkmakefile.c Mon Jun 25 17:17:47 2018 (r335642)
@@ -46,6 +46,7 @@ static const char rcsid[] =
#include <ctype.h>
#include <err.h>
#include <stdarg.h>
+#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <sys/param.h>
@@ -238,6 +239,63 @@ makehints(void)
moveifchanged(path("hints.c.new"), path("hints.c"));
}
+static void
+sanitize_envline(char *result, const char *src)
+{
+ const char *eq;
+ char c, *dst;
+ bool leading;
+
+ /* If there is no '=' it's not a well-formed name=value line. */
+ if ((eq = strchr(src, '=')) == NULL) {
+ *result = 0;
+ return;
+ }
+ dst = result;
+
+ /* Copy chars before the '=', skipping any leading spaces/quotes. */
+ leading = true;
+ while (src < eq) {
+ c = *src++;
+ if (leading && (isspace(c) || c == '"'))
+ continue;
+ *dst++ = c;
+ leading = false;
+ }
+
+ /* If it was all leading space, we don't have a well-formed line. */
+ if (leading) {
+ *result = 0;
+ return;
+ }
+
+ /* Trim spaces/quotes immediately before the '=', then copy the '='. */
+ while (isspace(dst[-1]) || dst[-1] == '"')
+ --dst;
+ *dst++ = *src++;
+
+ /* Copy chars after the '=', skipping any leading whitespace. */
+ leading = true;
+ while ((c = *src++) != 0) {
+ if (leading && (isspace(c) || c == '"'))
+ continue;
+ *dst++ = c;
+ leading = false;
+ }
+
+ /* If it was all leading space, it's a valid 'var=' (nil value). */
+ if (leading) {
+ *dst = 0;
+ return;
+ }
+
+ /* Trim trailing whitespace and quotes. */
+ while (isspace(dst[-1]) || dst[-1] == '"')
+ --dst;
+
+ *dst = 0;
+}
+
/*
* Build env.c from the skeleton
*/
@@ -245,8 +303,8 @@ void
makeenv(void)
{
FILE *ifp, *ofp;
- char line[BUFSIZ];
- char *s;
+ char line[BUFSIZ], result[BUFSIZ], *linep;
+ struct envvar *envvar;
if (env) {
ifp = fopen(env, "r");
@@ -265,34 +323,19 @@ makeenv(void)
fprintf(ofp, "char static_env[] = {\n");
if (ifp) {
while (fgets(line, BUFSIZ, ifp) != NULL) {
- /* zap trailing CR and/or LF */
- while ((s = strrchr(line, '\n')) != NULL)
- *s = '\0';
- while ((s = strrchr(line, '\r')) != NULL)
- *s = '\0';
- /* remove # comments */
- s = strchr(line, '#');
- if (s)
- *s = '\0';
- /* remove any whitespace and " characters */
- s = line;
- while (*s) {
- if (*s == ' ' || *s == '\t' || *s == '"') {
- while (*s) {
- s[0] = s[1];
- s++;
- }
- /* start over */
- s = line;
- continue;
- }
- s++;
- }
+ sanitize_envline(result, line);
/* anything left? */
- if (*line == '\0')
+ if (*result == '\0')
continue;
- fprintf(ofp, "\"%s\\0\"\n", line);
+ fprintf(ofp, "\"%s\\0\"\n", result);
}
+ }
+ STAILQ_FOREACH(envvar, &envvars, envvar_next) {
+ linep = envvar->env_str;
+ sanitize_envline(result, linep);
+ if (*result == '\0')
+ continue;
+ fprintf(ofp, "\"%s\\0\"\n", result);
}
fprintf(ofp, "\"\\0\"\n};\n");
if (ifp)
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