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author | msmith <msmith@FreeBSD.org> | 1998-10-09 00:31:29 +0000 |
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committer | msmith <msmith@FreeBSD.org> | 1998-10-09 00:31:29 +0000 |
commit | d8d7e646f416a5174e264ad88911d935fa412354 (patch) | |
tree | f78e033be979761a6b4cf211e175242d89238a37 /sys/kern/kern_environment.c | |
parent | 0d4797aebc4ad480e6cdd4e03e1bf50e864c74c5 (diff) | |
download | FreeBSD-src-d8d7e646f416a5174e264ad88911d935fa412354.zip FreeBSD-src-d8d7e646f416a5174e264ad88911d935fa412354.tar.gz |
Kernel environment access, preloaded module lookup.
Diffstat (limited to 'sys/kern/kern_environment.c')
-rw-r--r-- | sys/kern/kern_environment.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/sys/kern/kern_environment.c b/sys/kern/kern_environment.c new file mode 100644 index 0000000..400da45 --- /dev/null +++ b/sys/kern/kern_environment.c @@ -0,0 +1,126 @@ +/*- + * Copyright (c) 1998 Michael Smith + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $Id$ + +/* + * The unified bootloader passes us a pointer to a preserved copy of + * bootstrap/kernel environment variables. + * We make these available using sysctl for both in-kernel and + * out-of-kernel consumers. + * + * Note that the current sysctl infrastructure doesn't allow + * dynamic insertion or traversal through handled spaces. Grr. + */ + +#include <sys/param.h> +#include <sys/kernel.h> +#include <sys/systm.h> +#include <sys/sysctl.h> +#include <sys/libkern.h> +#include <machine/bootinfo.h> + +char *kern_envp; + +static char *kernenv_next(char *cp); + +static void +kernenv_init(void* arg) +{ + if (bootinfo.bi_envp != 0) + kern_envp = (char *)bootinfo.bi_envp; +} + +SYSINIT(kernenv, SI_SUB_CONSOLE, SI_ORDER_FIRST, kernenv_init, 0); + +char * +getenv(char *name) +{ + char *cp, *ep; + int len; + + for (cp = kern_envp; cp != NULL; cp = kernenv_next(cp)) { + for (ep = cp; (*ep != '=') && (*ep != 0); ep++) + ; + len = ep - cp; + if (*ep = '=') + ep++; + if (!strncmp(name, cp, len)) + return(ep); + } + return(NULL); +} + + +static int +sysctl_kernenv SYSCTL_HANDLER_ARGS +{ + int *name = (int *)arg1; + u_int namelen = arg2; + char *cp; + int i, error; + + if (kern_envp == NULL) + return(ENOENT); + + name++; + namelen--; + + if (namelen != 1) + return(EINVAL); + + cp = kern_envp; + for (i = 0; i < name[0]; i++) { + cp = kernenv_next(cp); + if (cp == NULL) + break; + } + + if (cp == NULL) + return(ENOENT); + + error = SYSCTL_OUT(req, cp, strlen(cp) + 1); + return (error); +} + +SYSCTL_NODE(_kern, OID_AUTO, environment, CTLFLAG_RD, sysctl_kernenv, "kernel environment space"); + +/* + * Find the next entry after the one which (cp) falls within, return a + * pointer to its start or NULL if there are no more. + */ +static char * +kernenv_next(char *cp) +{ + if (cp != NULL) { + while (*cp != 0) + cp++; + cp++; + if (*cp == 0) + cp = NULL; + } + return(cp); +} + |