Date: Mon, 25 Jun 2018 17:17:48 +0000 (UTC) From: Kyle Evans <kevans@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r335642 - head/usr.sbin/config Message-ID: <201806251717.w5PHHmBh004211@repo.freebsd.org>
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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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