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/* $OpenBSD: env.c,v 1.6 2017/04/06 21:12:06 tedu Exp $ */ |
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/* |
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* Copyright (c) 2016 Ted Unangst <tedu@openbsd.org> |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/types.h> |
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#include <sys/tree.h> |
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#include <string.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <err.h> |
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#include <unistd.h> |
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#include <errno.h> |
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#include "doas.h" |
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struct envnode { |
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RB_ENTRY(envnode) node; |
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const char *key; |
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const char *value; |
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}; |
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struct env { |
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RB_HEAD(envtree, envnode) root; |
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u_int count; |
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}; |
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static int |
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envcmp(struct envnode *a, struct envnode *b) |
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{ |
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return strcmp(a->key, b->key); |
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} |
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RB_GENERATE_STATIC(envtree, envnode, node, envcmp) |
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static struct envnode * |
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createnode(const char *key, const char *value) |
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{ |
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struct envnode *node; |
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node = malloc(sizeof(*node)); |
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if (!node) |
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err(1, NULL); |
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node->key = strdup(key); |
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node->value = strdup(value); |
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if (!node->key || !node->value) |
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err(1, NULL); |
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return node; |
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} |
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static void |
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freenode(struct envnode *node) |
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{ |
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free((char *)node->key); |
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free((char *)node->value); |
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free(node); |
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} |
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static struct env * |
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createenv(const struct rule *rule) |
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{ |
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struct env *env; |
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u_int i; |
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env = malloc(sizeof(*env)); |
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if (!env) |
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err(1, NULL); |
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RB_INIT(&env->root); |
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env->count = 0; |
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if (rule->options & KEEPENV) { |
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extern const char **environ; |
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for (i = 0; environ[i] != NULL; i++) { |
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struct envnode *node; |
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const char *e, *eq; |
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size_t len; |
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char name[1024]; |
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e = environ[i]; |
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/* ignore invalid or overlong names */ |
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if ((eq = strchr(e, '=')) == NULL || eq == e) |
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continue; |
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len = eq - e; |
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if (len > sizeof(name) - 1) |
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continue; |
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memcpy(name, e, len); |
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name[len] = '\0'; |
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node = createnode(name, eq + 1); |
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if (RB_INSERT(envtree, &env->root, node)) { |
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/* ignore any later duplicates */ |
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freenode(node); |
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} else { |
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env->count++; |
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} |
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} |
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} |
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return env; |
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} |
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static char ** |
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flattenenv(struct env *env) |
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{ |
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char **envp; |
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struct envnode *node; |
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u_int i; |
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envp = reallocarray(NULL, env->count + 1, sizeof(char *)); |
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if (!envp) |
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err(1, NULL); |
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i = 0; |
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RB_FOREACH(node, envtree, &env->root) { |
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if (asprintf(&envp[i], "%s=%s", node->key, node->value) == -1) |
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err(1, NULL); |
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i++; |
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} |
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envp[i] = NULL; |
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return envp; |
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} |
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static void |
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fillenv(struct env *env, const char **envlist) |
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{ |
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struct envnode *node, key; |
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const char *e, *eq; |
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const char *val; |
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char name[1024]; |
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u_int i; |
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size_t len; |
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for (i = 0; envlist[i]; i++) { |
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e = envlist[i]; |
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/* parse out env name */ |
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if ((eq = strchr(e, '=')) == NULL) |
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len = strlen(e); |
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else |
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len = eq - e; |
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if (len > sizeof(name) - 1) |
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continue; |
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memcpy(name, e, len); |
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name[len] = '\0'; |
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/* delete previous copies */ |
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key.key = name; |
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if (*name == '-') |
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key.key = name + 1; |
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if ((node = RB_FIND(envtree, &env->root, &key))) { |
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RB_REMOVE(envtree, &env->root, node); |
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freenode(node); |
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env->count--; |
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} |
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if (*name == '-') |
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continue; |
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/* assign value or inherit from environ */ |
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if (eq) { |
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val = eq + 1; |
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if (*val == '$') |
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val = getenv(val + 1); |
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} else { |
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val = getenv(name); |
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} |
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/* at last, we have something to insert */ |
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if (val) { |
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node = createnode(name, val); |
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RB_INSERT(envtree, &env->root, node); |
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env->count++; |
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} |
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} |
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} |
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char ** |
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prepenv(const struct rule *rule) |
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{ |
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static const char *safeset[] = { |
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"DISPLAY", "HOME", "LOGNAME", "MAIL", |
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"PATH", "TERM", "USER", "USERNAME", |
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NULL |
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}; |
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struct env *env; |
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env = createenv(rule); |
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/* if we started with blank, fill some defaults then apply rules */ |
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if (!(rule->options & KEEPENV)) |
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fillenv(env, safeset); |
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if (rule->envlist) |
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fillenv(env, rule->envlist); |
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return flattenenv(env); |
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} |