diff options
Diffstat (limited to 'usr.bin/doas')
-rw-r--r-- | usr.bin/doas/CVS/Entries | 8 | ||||
-rw-r--r-- | usr.bin/doas/CVS/Repository | 1 | ||||
-rw-r--r-- | usr.bin/doas/CVS/Root | 1 | ||||
-rw-r--r-- | usr.bin/doas/Makefile | 15 | ||||
-rw-r--r-- | usr.bin/doas/doas.1 | 130 | ||||
-rw-r--r-- | usr.bin/doas/doas.c | 482 | ||||
-rw-r--r-- | usr.bin/doas/doas.conf.5 | 149 | ||||
-rw-r--r-- | usr.bin/doas/doas.h | 48 | ||||
-rw-r--r-- | usr.bin/doas/env.c | 235 | ||||
-rw-r--r-- | usr.bin/doas/parse.c | 868 | ||||
-rw-r--r-- | usr.bin/doas/parse.tab.h | 10 | ||||
-rw-r--r-- | usr.bin/doas/parse.y | 343 | ||||
-rw-r--r-- | usr.bin/doas/persist.c | 133 |
13 files changed, 2423 insertions, 0 deletions
diff --git a/usr.bin/doas/CVS/Entries b/usr.bin/doas/CVS/Entries new file mode 100644 index 0000000..dbdad45 --- /dev/null +++ b/usr.bin/doas/CVS/Entries @@ -0,0 +1,8 @@ +/Makefile/1.3/Mon Jul 3 22:21:47 2017// +/doas.1/1.23/Thu Jul 4 19:04:17 2019// +/doas.c/1.82/Fri Oct 18 17:15:45 2019// +/doas.conf.5/1.42/Mon Feb 10 13:18:20 2020// +/doas.h/1.15/Mon Jun 17 19:51:23 2019// +/env.c/1.10/Sun Jul 7 19:21:28 2019// +/parse.y/1.27/Wed Jul 11 07:39:22 2018// +D diff --git a/usr.bin/doas/CVS/Repository b/usr.bin/doas/CVS/Repository new file mode 100644 index 0000000..84a451b --- /dev/null +++ b/usr.bin/doas/CVS/Repository @@ -0,0 +1 @@ +src/usr.bin/doas diff --git a/usr.bin/doas/CVS/Root b/usr.bin/doas/CVS/Root new file mode 100644 index 0000000..3811072 --- /dev/null +++ b/usr.bin/doas/CVS/Root @@ -0,0 +1 @@ +/cvs diff --git a/usr.bin/doas/Makefile b/usr.bin/doas/Makefile new file mode 100644 index 0000000..f2e5529 --- /dev/null +++ b/usr.bin/doas/Makefile @@ -0,0 +1,15 @@ +# $OpenBSD: Makefile,v 1.3 2017/07/03 22:21:47 espie Exp $ + +SRCS= parse.y doas.c env.c + +PROG= doas +MAN= doas.1 doas.conf.5 + +BINOWN= root +BINMODE=4555 + +CFLAGS+= -I${.CURDIR} +COPTS+= -Wall +YFLAGS= + +.include <bsd.prog.mk> diff --git a/usr.bin/doas/doas.1 b/usr.bin/doas/doas.1 new file mode 100644 index 0000000..c7196e3 --- /dev/null +++ b/usr.bin/doas/doas.1 @@ -0,0 +1,130 @@ +.\" $OpenBSD: doas.1,v 1.23 2019/07/04 19:04:17 tedu Exp $ +.\" +.\"Copyright (c) 2015 Ted Unangst <tedu@openbsd.org> +.\" +.\"Permission to use, copy, modify, and distribute this software for any +.\"purpose with or without fee is hereby granted, provided that the above +.\"copyright notice and this permission notice appear in all copies. +.\" +.\"THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +.\"WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +.\"MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +.\"ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +.\"WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +.\"ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +.\"OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +.Dd $Mdocdate: July 4 2019 $ +.Dt DOAS 1 +.Os +.Sh NAME +.Nm doas +.Nd execute commands as another user +.Sh SYNOPSIS +.Nm doas +.Op Fl Lns +.Op Fl C Ar config +.Op Fl u Ar user +.Ar command +.Op Ar args +.Sh DESCRIPTION +The +.Nm +utility executes the given command as another user. +The +.Ar command +argument is mandatory unless +.Fl C , +.Fl L , +or +.Fl s +is specified. +.Pp +The user will be required to authenticate by entering their password, +unless configured otherwise. +.Pp +By default, a new environment is created. +The variables +.Ev HOME , +.Ev LOGNAME , +.Ev PATH , +.Ev SHELL , +and +.Ev USER +and the +.Xr umask 2 +are set to values appropriate for the target user. +.Ev DOAS_USER +is set to the name of the user executing +.Nm . +The variables +.Ev DISPLAY +and +.Ev TERM +are inherited from the current environment. +This behavior may be modified by the config file. +The working directory is not changed. +.Pp +The options are as follows: +.Bl -tag -width tenletters +.It Fl C Ar config +Parse and check the configuration file +.Ar config , +then exit. +If +.Ar command +is supplied, +.Nm +will also perform command matching. +In the latter case +either +.Sq permit , +.Sq permit nopass +or +.Sq deny +will be printed on standard output, depending on command +matching results. +No command is executed. +.It Fl L +Clear any persisted authorizations from previous invocations, +then immediately exit. +No command is executed. +.It Fl n +Non interactive mode, fail if +.Nm +would prompt for password. +.It Fl s +Execute the shell from +.Ev SHELL +or +.Pa /etc/passwd . +.It Fl u Ar user +Execute the command as +.Ar user . +The default is root. +.El +.Sh EXIT STATUS +.Ex -std doas +It may fail for one of the following reasons: +.Pp +.Bl -bullet -compact +.It +The config file +.Pa /etc/doas.conf +could not be parsed. +.It +The user attempted to run a command which is not permitted. +.It +The password was incorrect. +.It +The specified command was not found or is not executable. +.El +.Sh SEE ALSO +.Xr su 1 , +.Xr doas.conf 5 +.Sh HISTORY +The +.Nm +command first appeared in +.Ox 5.8 . +.Sh AUTHORS +.An Ted Unangst Aq Mt tedu@openbsd.org diff --git a/usr.bin/doas/doas.c b/usr.bin/doas/doas.c new file mode 100644 index 0000000..15220e4 --- /dev/null +++ b/usr.bin/doas/doas.c @@ -0,0 +1,482 @@ +/* $OpenBSD: doas.c,v 1.82 2019/10/18 17:15:45 tedu Exp $ */ +/* + * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif + +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/ioctl.h> + +#include <limits.h> +#include <readpassphrase.h> +#include <string.h> +#include <stdio.h> +#include <stdlib.h> +#include <err.h> +#include <unistd.h> +#include <pwd.h> +#include <grp.h> +#include <syslog.h> +#include <errno.h> +#include <fcntl.h> +#include <shadow.h> + +#include "doas.h" + +#ifndef UID_MAX +#define UID_MAX 65535 +#endif + +#ifndef GID_MAX +#define GID_MAX 65535 +#endif + +static void __dead +usage(void) +{ + fprintf(stderr, "usage: doas [-Lns] [-C config] [-u user]" + " command [args]\n"); + exit(1); +} + +static int +parseuid(const char *s, uid_t *uid) +{ + struct passwd *pw; + const char *errstr; + + if ((pw = getpwnam(s)) != NULL) { + *uid = pw->pw_uid; + if (*uid == UID_MAX) + return -1; + return 0; + } + *uid = strtonum(s, 0, UID_MAX - 1, &errstr); + if (errstr) + return -1; + return 0; +} + +static int +uidcheck(const char *s, uid_t desired) +{ + uid_t uid; + + if (parseuid(s, &uid) != 0) + return -1; + if (uid != desired) + return -1; + return 0; +} + +static int +parsegid(const char *s, gid_t *gid) +{ + struct group *gr; + const char *errstr; + + if ((gr = getgrnam(s)) != NULL) { + *gid = gr->gr_gid; + if (*gid == GID_MAX) + return -1; + return 0; + } + *gid = strtonum(s, 0, GID_MAX - 1, &errstr); + if (errstr) + return -1; + return 0; +} + +static int +match(uid_t uid, gid_t *groups, int ngroups, uid_t target, const char *cmd, + const char **cmdargs, struct rule *r) +{ + int i; + + if (r->ident[0] == ':') { + gid_t rgid; + if (parsegid(r->ident + 1, &rgid) == -1) + return 0; + for (i = 0; i < ngroups; i++) { + if (rgid == groups[i]) + break; + } + if (i == ngroups) + return 0; + } else { + if (uidcheck(r->ident, uid) != 0) + return 0; + } + if (r->target && uidcheck(r->target, target) != 0) + return 0; + if (r->cmd) { + if (strcmp(r->cmd, cmd)) + return 0; + if (r->cmdargs) { + /* if arguments were given, they should match explicitly */ + for (i = 0; r->cmdargs[i]; i++) { + if (!cmdargs[i]) + return 0; + if (strcmp(r->cmdargs[i], cmdargs[i])) + return 0; + } + if (cmdargs[i]) + return 0; + } + } + return 1; +} + +static int +permit(uid_t uid, gid_t *groups, int ngroups, const struct rule **lastr, + uid_t target, const char *cmd, const char **cmdargs) +{ + int i; + + *lastr = NULL; + for (i = 0; i < nrules; i++) { + if (match(uid, groups, ngroups, target, cmd, + cmdargs, rules[i])) + *lastr = rules[i]; + } + if (!*lastr) + return 0; + return (*lastr)->action == PERMIT; +} + +static void +parseconfig(const char *filename, int checkperms) +{ + extern FILE *yyfp; + extern int yyparse(void); + struct stat sb; + + yyfp = fopen(filename, "r"); + if (!yyfp) + err(1, checkperms ? "doas is not enabled, %s" : + "could not open config file %s", filename); + + if (checkperms) { + if (fstat(fileno(yyfp), &sb) != 0) + err(1, "fstat(\"%s\")", filename); + if ((sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) + errx(1, "%s is writable by group or other", filename); + if (sb.st_uid != 0) + errx(1, "%s is not owned by root", filename); + } + + yyparse(); + fclose(yyfp); + if (parse_errors) + exit(1); +} + +static void __dead +checkconfig(const char *confpath, int argc, char **argv, + uid_t uid, gid_t *groups, int ngroups, uid_t target) +{ + const struct rule *rule; + + setresuid(uid, uid, uid); + parseconfig(confpath, 0); + if (!argc) + exit(0); + + if (permit(uid, groups, ngroups, &rule, target, argv[0], + (const char **)argv + 1)) { + printf("permit%s\n", (rule->options & NOPASS) ? " nopass" : ""); + exit(0); + } else { + printf("deny\n"); + exit(1); + } +} + +static int +verifypasswd(const char *user, const char *pass) +{ + struct spwd *sp; + char *p1, *p2; + + sp = getspnam(user); + if (!sp) + return 0; + p1 = sp->sp_pwdp; + if (p1[0] == '!' || p1[0] == '*') + return 0; + p2 = crypt(pass, p1); + if (!p2) + return 0; + return strcmp(p1, p2) == 0; +} + +static void +authuser(char *myname, int persist) +{ + char *challenge = NULL, *response, rbuf[1024], cbuf[128]; + int fd = -1, valid = 0; + + if (persist) { + fd = openpersist(&valid); + if (valid) + goto good; + } + + if (!challenge) { + char host[HOST_NAME_MAX + 1]; + if (gethostname(host, sizeof(host))) + snprintf(host, sizeof(host), "?"); + snprintf(cbuf, sizeof(cbuf), + "\rdoas (%.32s@%.32s) password: ", myname, host); + challenge = cbuf; + } + response = readpassphrase(challenge, rbuf, sizeof(rbuf), + RPP_REQUIRE_TTY); + if (response == NULL && errno == ENOTTY) { + syslog(LOG_NOTICE, "tty required for %s", myname); + errx(1, "a tty is required"); + } + if (!verifypasswd(myname, response)) { + explicit_bzero(rbuf, sizeof(rbuf)); + syslog(LOG_NOTICE, "failed auth for %s", myname); + errx(1, "Authorization failed"); + } + explicit_bzero(rbuf, sizeof(rbuf)); +good: + if (fd != -1) { + setpersist(fd); + close(fd); + } +} + +int +unveilcommands(const char *ipath, const char *cmd) +{ + char *path = NULL, *p; + int unveils = 0; + + if (strchr(cmd, '/') != NULL) { + if (unveil(cmd, "x") != -1) + unveils++; + goto done; + } + + if (!ipath) { + errno = ENOENT; + goto done; + } + path = strdup(ipath); + if (!path) { + errno = ENOENT; + goto done; + } + for (p = path; p && *p; ) { + char buf[PATH_MAX]; + char *cp = strsep(&p, ":"); + + if (cp) { + int r = snprintf(buf, sizeof buf, "%s/%s", cp, cmd); + if (r >= 0 && r < sizeof buf) { + if (unveil(buf, "x") != -1) + unveils++; + } + } + } +done: + free(path); + return (unveils); +} + +int +main(int argc, char **argv) +{ + const char *safepath = "/bin"; + const char *confpath = NULL; + char *shargv[] = { NULL, NULL }; + char *sh; + const char *p; + const char *cmd; + char cmdline[LINE_MAX]; + char mypwbuf[1024], targpwbuf[1024]; + struct passwd mypwstore, targpwstore; + struct passwd *mypw, *targpw; + const struct rule *rule; + uid_t uid; + uid_t target = 0; + gid_t groups[NGROUPS_MAX + 1]; + int ngroups; + int i, ch, rv; + int sflag = 0; + int nflag = 0; + char cwdpath[PATH_MAX]; + const char *cwd; + char **envp; + + setprogname("doas"); + openlog("doas", 0, LOG_AUTHPRIV); + + uid = getuid(); + + while ((ch = getopt(argc, argv, "C:Lnsu:")) != -1) { + switch (ch) { + case 'C': + confpath = optarg; + break; + case 'L': + exit(clearpersist() != 0); + case 'u': + if (parseuid(optarg, &target) != 0) + errx(1, "unknown user"); + break; + case 'n': + nflag = 1; + break; + case 's': + sflag = 1; + break; + default: + usage(); + break; + } + } + argv += optind; + argc -= optind; + + if (confpath) { + if (sflag) + usage(); + } else if ((!sflag && !argc) || (sflag && argc)) + usage(); + + rv = getpwuid_r(uid, &mypwstore, mypwbuf, sizeof(mypwbuf), &mypw); + if (rv != 0) + err(1, "getpwuid_r failed"); + if (mypw == NULL) + errx(1, "no passwd entry for self"); + ngroups = getgroups(NGROUPS_MAX, groups); + if (ngroups == -1) + err(1, "can't get groups"); + groups[ngroups++] = getgid(); + + if (sflag) { + sh = getenv("SHELL"); + if (sh == NULL || *sh == '\0') { + shargv[0] = mypw->pw_shell; + } else + shargv[0] = sh; + argv = shargv; + argc = 1; + } + + if (confpath) { + checkconfig(confpath, argc, argv, uid, groups, ngroups, + target); + exit(1); /* fail safe */ + } + + if (geteuid()) + errx(1, "not installed setuid"); + + parseconfig("/etc/doas.conf", 1); + + /* cmdline is used only for logging, no need to abort on truncate */ + (void)strlcpy(cmdline, argv[0], sizeof(cmdline)); + for (i = 1; i < argc; i++) { + if (strlcat(cmdline, " ", sizeof(cmdline)) >= sizeof(cmdline)) + break; + if (strlcat(cmdline, argv[i], sizeof(cmdline)) >= sizeof(cmdline)) + break; + } + + cmd = argv[0]; + if (!permit(uid, groups, ngroups, &rule, target, cmd, + (const char **)argv + 1)) { + syslog(LOG_NOTICE, "failed command for %s: %s", mypw->pw_name, cmdline); + errno = EPERM; + err(1, NULL); + } + + if (!(rule->options & NOPASS)) { + if (nflag) + errx(1, "Authorization required"); + + authuser(mypw->pw_name, rule->options & PERSIST); + } + + if ((p = getenv("PATH")) != NULL) + formerpath = strdup(p); + if (formerpath == NULL) + formerpath = ""; + + if (unveil(_PATH_LOGIN_CONF, "r") == -1 || + unveil(_PATH_LOGIN_CONF ".db", "r") == -1) + err(1, "unveil"); + if (rule->cmd) { + if (setenv("PATH", safepath, 1) == -1) + err(1, "failed to set PATH '%s'", safepath); + } + if (unveilcommands(getenv("PATH"), cmd) == 0) + goto fail; + + if (pledge("stdio rpath getpw exec id", NULL) == -1) + err(1, "pledge"); + + rv = getpwuid_r(target, &targpwstore, targpwbuf, sizeof(targpwbuf), &targpw); + if (rv != 0) + err(1, "getpwuid_r failed"); + if (targpw == NULL) + errx(1, "no passwd entry for target"); + + if (initgroups(targpw->pw_name, targpw->pw_gid) < 0) + err(1, "initgroups"); + if (setgid(targpw->pw_gid) < 0) + err(1, "setgid"); + if (setuid(targpw->pw_uid) < 0) + err(1, "setuid"); + + if (pledge("stdio rpath exec", NULL) == -1) + err(1, "pledge"); + + if (getcwd(cwdpath, sizeof(cwdpath)) == NULL) + cwd = "(failed)"; + else + cwd = cwdpath; + + if (pledge("stdio exec", NULL) == -1) + err(1, "pledge"); + + syslog(LOG_INFO, "%s ran command %s as %s from %s", + mypw->pw_name, cmdline, targpw->pw_name, cwd); + + envp = prepenv(rule, mypw, targpw); + + /* setusercontext set path for the next process, so reset it for us */ + if (rule->cmd) { + if (setenv("PATH", safepath, 1) == -1) + err(1, "failed to set PATH '%s'", safepath); + } else { + if (setenv("PATH", formerpath, 1) == -1) + err(1, "failed to set PATH '%s'", formerpath); + } + execvpe(cmd, argv, envp); +fail: + if (errno == ENOENT) + errx(1, "%s: command not found", cmd); + err(1, "%s", cmd); +} diff --git a/usr.bin/doas/doas.conf.5 b/usr.bin/doas/doas.conf.5 new file mode 100644 index 0000000..70379ee --- /dev/null +++ b/usr.bin/doas/doas.conf.5 @@ -0,0 +1,149 @@ +.\" $OpenBSD: doas.conf.5,v 1.42 2020/02/10 13:18:20 schwarze Exp $ +.\" +.\"Copyright (c) 2015 Ted Unangst <tedu@openbsd.org> +.\" +.\"Permission to use, copy, modify, and distribute this software for any +.\"purpose with or without fee is hereby granted, provided that the above +.\"copyright notice and this permission notice appear in all copies. +.\" +.\"THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +.\"WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +.\"MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +.\"ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +.\"WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +.\"ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +.\"OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +.Dd $Mdocdate: February 10 2020 $ +.Dt DOAS.CONF 5 +.Os +.Sh NAME +.Nm doas.conf +.Nd doas configuration file +.Sh DESCRIPTION +The +.Xr doas 1 +utility executes commands as other users according to the rules +in the +.Nm +configuration file. +.Pp +The rules have the following format: +.Bd -ragged -offset indent +.Ic permit Ns | Ns Ic deny +.Op Ar options +.Ar identity +.Op Ic as Ar target +.Op Ic cmd Ar command Op Ic args No ... +.Ed +.Pp +Rules consist of the following parts: +.Bl -tag -width 11n +.It Ic permit Ns | Ns Ic deny +The action to be taken if this rule matches. +.It Ar options +Options are: +.Bl -tag -width keepenv +.It Ic nopass +The user is not required to enter a password. +.It Ic persist +After the user successfully authenticates, do not ask for a password +again for some time. +.It Ic keepenv +Environment variables other than those listed in +.Xr doas 1 +are retained when creating the environment for the new process. +.It Ic setenv { Oo Ar variable ... Oc Oo Ar variable=value ... Oc Ic } +Keep or set the space-separated specified variables. +Variables may also be removed with a leading +.Sq - +or set using the latter syntax. +If the first character of +.Ar value +is a +.Ql $ +then the value to be set is taken from the existing environment +variable of the indicated name. +This option is processed after the default environment has been created. +.El +.It Ar identity +The username to match. +Groups may be specified by prepending a colon +.Pq Sq \&: . +Numeric IDs are also accepted. +.It Ic as Ar target +The target user the running user is allowed to run the command as. +The default is all users. +.It Ic cmd Ar command +The command the user is allowed or denied to run. +The default is all commands. +Be advised that it is best to specify absolute paths. +If a relative path is specified, only a restricted +.Ev PATH +will be searched. +.It Ic args Op Ar argument ... +Arguments to command. +The command arguments provided by the user need to match those specified. +The keyword +.Ic args +alone means that command must be run without any arguments. +.El +.Pp +The last matching rule determines the action taken. +If no rule matches, the action is denied. +.Pp +Comments can be put anywhere in the file using a hash mark +.Pq Sq # , +and extend to the end of the current line. +.Pp +The following quoting rules apply: +.Bl -dash +.It +The text between a pair of double quotes +.Pq Sq \&" +is taken as is. +.It +The backslash character +.Pq Sq \e +escapes the next character, including new line characters, outside comments; +as a result, comments may not be extended over multiple lines. +.It +If quotes or backslashes are used in a word, +it is not considered a keyword. +.El +.Sh FILES +.Bl -tag -width /etc/examples/doas.conf -compact +.It Pa /etc/doas.conf +.Xr doas 1 +configuration file +.It Pa /etc/examples/doas.conf +example configuration file +.El +.Sh EXAMPLES +The following example permits user aja to install packages +from a preferred mirror; +group wheel to execute commands as any user while keeping the environment +variables +.Ev PS1 +and +.Ev SSH_AUTH_SOCK +and +unsetting +.Ev ENV ; +permits tedu to run procmap as root without a password; +and additionally permits root to run unrestricted commands as itself +while retaining the original PATH. +.Bd -literal -offset indent +permit persist setenv { PKG_CACHE PKG_PATH } aja cmd pkg_add +permit setenv { -ENV PS1=$DOAS_PS1 SSH_AUTH_SOCK } :wheel +permit nopass tedu as root cmd /usr/sbin/procmap +permit nopass keepenv setenv { PATH } root as root +.Ed +.Sh SEE ALSO +.Xr doas 1 +.Sh HISTORY +The +.Nm +configuration file first appeared in +.Ox 5.8 . +.Sh AUTHORS +.An Ted Unangst Aq Mt tedu@openbsd.org diff --git a/usr.bin/doas/doas.h b/usr.bin/doas/doas.h new file mode 100644 index 0000000..c97986e --- /dev/null +++ b/usr.bin/doas/doas.h @@ -0,0 +1,48 @@ +/* $OpenBSD: doas.h,v 1.15 2019/06/17 19:51:23 tedu Exp $ */ +/* + * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +struct rule { + int action; + int options; + const char *ident; + const char *target; + const char *cmd; + const char **cmdargs; + const char **envlist; +}; + +extern struct rule **rules; +extern int nrules; +extern int parse_errors; + +extern const char *formerpath; + +struct passwd; + +char **prepenv(const struct rule *, const struct passwd *, + const struct passwd *); + +int openpersist(int *valid); +int setpersist(int fd); +int clearpersist(void); + +#define PERMIT 1 +#define DENY 2 + +#define NOPASS 0x1 +#define KEEPENV 0x2 +#define PERSIST 0x4 diff --git a/usr.bin/doas/env.c b/usr.bin/doas/env.c new file mode 100644 index 0000000..2d93a40 --- /dev/null +++ b/usr.bin/doas/env.c @@ -0,0 +1,235 @@ +/* $OpenBSD: env.c,v 1.10 2019/07/07 19:21:28 tedu Exp $ */ +/* + * Copyright (c) 2016 Ted Unangst <tedu@openbsd.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <sys/types.h> +#include <sys/tree.h> + +#include <string.h> +#include <stdio.h> +#include <stdlib.h> +#include <err.h> +#include <unistd.h> +#include <errno.h> +#include <pwd.h> + +#include "doas.h" + +const char *formerpath; + +struct envnode { + RB_ENTRY(envnode) node; + const char *key; + const char *value; +}; + +struct env { + RB_HEAD(envtree, envnode) root; + u_int count; +}; + +static void fillenv(struct env *env, const char **envlist); + +static int +envcmp(struct envnode *a, struct envnode *b) +{ + return strcmp(a->key, b->key); +} +RB_GENERATE_STATIC(envtree, envnode, node, envcmp) + +static struct envnode * +createnode(const char *key, const char *value) +{ + struct envnode *node; + + node = malloc(sizeof(*node)); + if (!node) + err(1, NULL); + node->key = strdup(key); + node->value = strdup(value); + if (!node->key || !node->value) + err(1, NULL); + return node; +} + +static void +freenode(struct envnode *node) +{ + free((char *)node->key); + free((char *)node->value); + free(node); +} + +static void +addnode(struct env *env, const char *key, const char *value) +{ + struct envnode *node; + + node = createnode(key, value); + RB_INSERT(envtree, &env->root, node); + env->count++; +} + +static struct env * +createenv(const struct rule *rule, const struct passwd *mypw, + const struct passwd *targpw) +{ + static const char *copyset[] = { + "DISPLAY", "TERM", + NULL + }; + struct env *env; + u_int i; + + env = malloc(sizeof(*env)); + if (!env) + err(1, NULL); + RB_INIT(&env->root); + env->count = 0; + + addnode(env, "DOAS_USER", mypw->pw_name); + addnode(env, "HOME", targpw->pw_dir); + addnode(env, "LOGNAME", targpw->pw_name); + addnode(env, "PATH", getenv("PATH")); + addnode(env, "SHELL", targpw->pw_shell); + addnode(env, "USER", targpw->pw_name); + + fillenv(env, copyset); + + if (rule->options & KEEPENV) { + extern const char **environ; + + for (i = 0; environ[i] != NULL; i++) { + struct envnode *node; + const char *e, *eq; + size_t len; + char name[1024]; + + e = environ[i]; + + /* ignore invalid or overlong names */ + if ((eq = strchr(e, '=')) == NULL || eq == e) + continue; + len = eq - e; + if (len > sizeof(name) - 1) + continue; + memcpy(name, e, len); + name[len] = '\0'; + + node = createnode(name, eq + 1); + if (RB_INSERT(envtree, &env->root, node)) { + /* ignore any later duplicates */ + freenode(node); + } else { + env->count++; + } + } + } + + return env; +} + +static char ** +flattenenv(struct env *env) +{ + char **envp; + struct envnode *node; + u_int i; + + envp = reallocarray(NULL, env->count + 1, sizeof(char *)); + if (!envp) + err(1, NULL); + i = 0; + RB_FOREACH(node, envtree, &env->root) { + if (asprintf(&envp[i], "%s=%s", node->key, node->value) == -1) + err(1, NULL); + i++; + } + envp[i] = NULL; + return envp; +} + +static void +fillenv(struct env *env, const char **envlist) +{ + struct envnode *node, key; + const char *e, *eq; + const char *val; + char name[1024]; + u_int i; + size_t len; + + for (i = 0; envlist[i]; i++) { + e = envlist[i]; + + /* parse out env name */ + if ((eq = strchr(e, '=')) == NULL) + len = strlen(e); + else + len = eq - e; + if (len > sizeof(name) - 1) + continue; + memcpy(name, e, len); + name[len] = '\0'; + + /* delete previous copies */ + key.key = name; + if (*name == '-') + key.key = name + 1; + if ((node = RB_FIND(envtree, &env->root, &key))) { + RB_REMOVE(envtree, &env->root, node); + freenode(node); + env->count--; + } + if (*name == '-') + continue; + + /* assign value or inherit from environ */ + if (eq) { + val = eq + 1; + if (*val == '$') { + if (strcmp(val + 1, "PATH") == 0) + val = formerpath; + else + val = getenv(val + 1); + } + } else { + if (strcmp(name, "PATH") == 0) + val = formerpath; + else + val = getenv(name); + } + /* at last, we have something to insert */ + if (val) { + node = createnode(name, val); + RB_INSERT(envtree, &env->root, node); + env->count++; + } + } +} + +char ** +prepenv(const struct rule *rule, const struct passwd *mypw, + const struct passwd *targpw) +{ + struct env *env; + + env = createenv(rule, mypw, targpw); + if (rule->envlist) + fillenv(env, rule->envlist); + + return flattenenv(env); +} diff --git a/usr.bin/doas/parse.c b/usr.bin/doas/parse.c new file mode 100644 index 0000000..abebdb2 --- /dev/null +++ b/usr.bin/doas/parse.c @@ -0,0 +1,868 @@ +/* original parser id follows */ +/* yysccsid[] = "@(#)yaccpar 1.9 (Berkeley) 02/21/93" */ +/* (use YYMAJOR/YYMINOR for ifdefs dependent on parser version) */ + +#define YYBYACC 1 +#define YYMAJOR 2 +#define YYMINOR 0 +#define YYPATCH 20200910 + +#define YYEMPTY (-1) +#define yyclearin (yychar = YYEMPTY) +#define yyerrok (yyerrflag = 0) +#define YYRECOVERING() (yyerrflag != 0) +#define YYENOMEM (-2) +#define YYEOF 0 +#define YYPREFIX "yy" + +#define YYPURE 0 + +#line 19 "usr.bin/doas/parse.y" +#include <sys/types.h> +#include <ctype.h> +#include <unistd.h> +#include <stdlib.h> +#include <stdint.h> +#include <stdarg.h> +#include <stdio.h> +#include <string.h> +#include <err.h> + +#include "doas.h" + +typedef struct { + union { + struct { + int action; + int options; + const char *cmd; + const char **cmdargs; + const char **envlist; + }; + const char **strlist; + const char *str; + }; + int lineno; + int colno; +} yystype; +#define YYSTYPE yystype + +FILE *yyfp; + +struct rule **rules; +int nrules; +static int maxrules; + +int parse_errors = 0; + +static void yyerror(const char *, ...); +static int yylex(void); + +static size_t +arraylen(const char **arr) +{ + size_t cnt = 0; + + while (*arr) { + cnt++; + arr++; + } + return cnt; +} + +#line 74 "usr.bin/doas/parse.c" + +#if ! defined(YYSTYPE) && ! defined(YYSTYPE_IS_DECLARED) +/* Default: YYSTYPE is the semantic value type. */ +typedef int YYSTYPE; +# define YYSTYPE_IS_DECLARED 1 +#endif + +/* compatibility with bison */ +#ifdef YYPARSE_PARAM +/* compatibility with FreeBSD */ +# ifdef YYPARSE_PARAM_TYPE +# define YYPARSE_DECL() yyparse(YYPARSE_PARAM_TYPE YYPARSE_PARAM) +# else +# define YYPARSE_DECL() yyparse(void *YYPARSE_PARAM) +# endif +#else +# define YYPARSE_DECL() yyparse(void) +#endif + +/* Parameters sent to lex. */ +#ifdef YYLEX_PARAM +# define YYLEX_DECL() yylex(void *YYLEX_PARAM) +# define YYLEX yylex(YYLEX_PARAM) +#else +# define YYLEX_DECL() yylex(void) +# define YYLEX yylex() +#endif + +#if !(defined(yylex) || defined(YYSTATE)) +int YYLEX_DECL(); +#endif + +/* Parameters sent to yyerror. */ +#ifndef YYERROR_DECL +#define YYERROR_DECL() yyerror(const char *s) +#endif +#ifndef YYERROR_CALL +#define YYERROR_CALL(msg) yyerror(msg) +#endif + +extern int YYPARSE_DECL(); + +#define TPERMIT 257 +#define TDENY 258 +#define TAS 259 +#define TCMD 260 +#define TARGS 261 +#define TNOPASS 262 +#define TPERSIST 263 +#define TKEEPENV 264 +#define TSETENV 265 +#define TSTRING 266 +#define YYERRCODE 256 +typedef short YYINT; +static const YYINT yylhs[] = { -1, + 0, 0, 0, 0, 1, 2, 2, 6, 6, 7, + 7, 7, 7, 8, 8, 3, 4, 4, 5, 5, + 9, 9, +}; +static const YYINT yylen[] = { 2, + 0, 2, 3, 2, 4, 2, 1, 0, 2, 1, + 1, 1, 4, 0, 2, 1, 0, 2, 0, 3, + 0, 2, +}; +static const YYINT yydefred[] = { 0, + 0, 0, 4, 8, 7, 2, 0, 0, 0, 3, + 16, 0, 10, 11, 12, 0, 9, 0, 0, 14, + 18, 0, 5, 0, 0, 15, 13, 14, 20, 0, +}; +static const YYINT yydgoto[] = { 2, + 7, 8, 12, 19, 23, 9, 17, 24, 29, +}; +static const YYINT yysindex[] = { -253, + -1, -6, 0, 0, 0, 0, 2, -256, -257, 0, + 0, -246, 0, 0, 0, -109, 0, -251, -244, 0, + 0, -249, 0, -123, -243, 0, 0, 0, 0, -247, +}; +static const YYINT yyrindex[] = { 1, + 0, 0, 0, 0, 0, 0, 0, 0, -245, 0, + 0, -10, 0, 0, 0, 0, 0, 0, 10, 0, + 0, 0, 0, 0, 12, 0, 0, 0, 0, 13, +}; +static const YYINT yygindex[] = { 0, + 0, 0, 0, 0, 0, 0, 0, -4, 0, +}; +#define YYTABLESIZE 259 +static const YYINT yytable[] = { 17, + 1, 27, 1, 6, 13, 14, 15, 16, 3, 11, + 1, 10, 18, 20, 21, 22, 25, 28, 26, 19, + 6, 21, 22, 30, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 26, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 17, + 4, 5, 0, 0, 0, 0, 0, 1, 1, +}; +static const YYINT yycheck[] = { 10, + 0, 125, 256, 10, 262, 263, 264, 265, 10, 266, + 10, 10, 259, 123, 266, 260, 266, 261, 266, 10, + 266, 10, 10, 28, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, 266, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, 260, + 257, 258, -1, -1, -1, -1, -1, 257, 258, +}; +#define YYFINAL 2 +#ifndef YYDEBUG +#define YYDEBUG 0 +#endif +#define YYMAXTOKEN 266 +#define YYUNDFTOKEN 278 +#define YYTRANSLATE(a) ((a) > YYMAXTOKEN ? YYUNDFTOKEN : (a)) +#if YYDEBUG +static const char *const yyname[] = { + +"end-of-file",0,0,0,0,0,0,0,0,0,"'\\n'",0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, +0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, +0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, +0,0,0,0,0,0,0,0,0,0,0,0,"'{'",0,"'}'",0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, +0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, +0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, +0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,"TPERMIT","TDENY", +"TAS","TCMD","TARGS","TNOPASS","TPERSIST","TKEEPENV","TSETENV","TSTRING",0,0,0, +0,0,0,0,0,0,0,0,"illegal-symbol", +}; +static const char *const yyrule[] = { +"$accept : grammar", +"grammar :", +"grammar : grammar '\\n'", +"grammar : grammar rule '\\n'", +"grammar : error '\\n'", +"rule : action ident target cmd", +"action : TPERMIT options", +"action : TDENY", +"options :", +"options : options option", +"option : TNOPASS", +"option : TPERSIST", +"option : TKEEPENV", +"option : TSETENV '{' strlist '}'", +"strlist :", +"strlist : strlist TSTRING", +"ident : TSTRING", +"target :", +"target : TAS TSTRING", +"cmd :", +"cmd : TCMD TSTRING args", +"args :", +"args : TARGS strlist", + +}; +#endif + +#if YYDEBUG +int yydebug; +#endif + +int yyerrflag; +int yychar; +YYSTYPE yyval; +YYSTYPE yylval; +int yynerrs; + +/* define the initial stack-sizes */ +#ifdef YYSTACKSIZE +#undef YYMAXDEPTH +#define YYMAXDEPTH YYSTACKSIZE +#else +#ifdef YYMAXDEPTH +#define YYSTACKSIZE YYMAXDEPTH +#else +#define YYSTACKSIZE 10000 +#define YYMAXDEPTH 10000 +#endif +#endif + +#define YYINITSTACKSIZE 200 + +typedef struct { + unsigned stacksize; + YYINT *s_base; + YYINT *s_mark; + YYINT *s_last; + YYSTYPE *l_base; + YYSTYPE *l_mark; +} YYSTACKDATA; +/* variables for the parser stack */ +static YYSTACKDATA yystack; +#line 189 "usr.bin/doas/parse.y" + +void +yyerror(const char *fmt, ...) +{ + va_list va; + + fprintf(stderr, "doas: "); + va_start(va, fmt); + vfprintf(stderr, fmt, va); + va_end(va); + fprintf(stderr, " at line %d\n", yylval.lineno + 1); + parse_errors++; +} + +static struct keyword { + const char *word; + int token; +} keywords[] = { + { "deny", TDENY }, + { "permit", TPERMIT }, + { "as", TAS }, + { "cmd", TCMD }, + { "args", TARGS }, + { "nopass", TNOPASS }, + { "persist", TPERSIST }, + { "keepenv", TKEEPENV }, + { "setenv", TSETENV }, +}; + +int +yylex(void) +{ + char buf[1024], *ebuf, *p, *str; + int i, c, quotes = 0, escape = 0, qpos = -1, nonkw = 0; + + p = buf; + ebuf = buf + sizeof(buf); + +repeat: + /* skip whitespace first */ + for (c = getc(yyfp); c == ' ' || c == '\t'; c = getc(yyfp)) + yylval.colno++; + + /* check for special one-character constructions */ + switch (c) { + case '\n': + yylval.colno = 0; + yylval.lineno++; + /* FALLTHROUGH */ + case '{': + case '}': + return c; + case '#': + /* skip comments; NUL is allowed; no continuation */ + while ((c = getc(yyfp)) != '\n') + if (c == EOF) + goto eof; + yylval.colno = 0; + yylval.lineno++; + return c; + case EOF: + goto eof; + } + + /* parsing next word */ + for (;; c = getc(yyfp), yylval.colno++) { + switch (c) { + case '\0': + yyerror("unallowed character NUL in column %d", + yylval.colno + 1); + escape = 0; + continue; + case '\\': + escape = !escape; + if (escape) + continue; + break; + case '\n': + if (quotes) + yyerror("unterminated quotes in column %d", + qpos + 1); + if (escape) { + nonkw = 1; + escape = 0; + yylval.colno = 0; + yylval.lineno++; + continue; + } + goto eow; + case EOF: + if (escape) + yyerror("unterminated escape in column %d", + yylval.colno); + if (quotes) + yyerror("unterminated quotes in column %d", + qpos + 1); + goto eow; + /* FALLTHROUGH */ + case '{': + case '}': + case '#': + case ' ': + case '\t': + if (!escape && !quotes) + goto eow; + break; + case '"': + if (!escape) { + quotes = !quotes; + if (quotes) { + nonkw = 1; + qpos = yylval.colno; + } + continue; + } + } + *p++ = c; + if (p == ebuf) { + yyerror("too long line"); + p = buf; + } + escape = 0; + } + +eow: + *p = 0; + if (c != EOF) + ungetc(c, yyfp); + if (p == buf) { + /* + * There could be a number of reasons for empty buffer, + * and we handle all of them here, to avoid cluttering + * the main loop. + */ + if (c == EOF) + goto eof; + else if (qpos == -1) /* accept, e.g., empty args: cmd foo args "" */ + goto repeat; + } + if (!nonkw) { + for (i = 0; i < sizeof(keywords) / sizeof(keywords[0]); i++) { + if (strcmp(buf, keywords[i].word) == 0) + return keywords[i].token; + } + } + if ((str = strdup(buf)) == NULL) + err(1, "%s", __func__); + yylval.str = str; + return TSTRING; + +eof: + if (ferror(yyfp)) + yyerror("input error reading config"); + return 0; +} +#line 456 "usr.bin/doas/parse.c" + +#if YYDEBUG +#include <stdio.h> /* needed for printf */ +#endif + +#include <stdlib.h> /* needed for malloc, etc */ +#include <string.h> /* needed for memset */ + +/* allocate initial stack or double stack size, up to YYMAXDEPTH */ +static int yygrowstack(YYSTACKDATA *data) +{ + int i; + unsigned newsize; + YYINT *newss; + YYSTYPE *newvs; + + if ((newsize = data->stacksize) == 0) + newsize = YYINITSTACKSIZE; + else if (newsize >= YYMAXDEPTH) + return YYENOMEM; + else if ((newsize *= 2) > YYMAXDEPTH) + newsize = YYMAXDEPTH; + + i = (int) (data->s_mark - data->s_base); + newss = (YYINT *)realloc(data->s_base, newsize * sizeof(*newss)); + if (newss == 0) + return YYENOMEM; + + data->s_base = newss; + data->s_mark = newss + i; + + newvs = (YYSTYPE *)realloc(data->l_base, newsize * sizeof(*newvs)); + if (newvs == 0) + return YYENOMEM; + + data->l_base = newvs; + data->l_mark = newvs + i; + + data->stacksize = newsize; + data->s_last = data->s_base + newsize - 1; + return 0; +} + +#if YYPURE || defined(YY_NO_LEAKS) +static void yyfreestack(YYSTACKDATA *data) +{ + free(data->s_base); + free(data->l_base); + memset(data, 0, sizeof(*data)); +} +#else +#define yyfreestack(data) /* nothing */ +#endif + +#define YYABORT goto yyabort +#define YYREJECT goto yyabort +#define YYACCEPT goto yyaccept +#define YYERROR goto yyerrlab + +int +YYPARSE_DECL() +{ + int yym, yyn, yystate; +#if YYDEBUG + const char *yys; + + if ((yys = getenv("YYDEBUG")) != 0) + { + yyn = *yys; + if (yyn >= '0' && yyn <= '9') + yydebug = yyn - '0'; + } +#endif + + yym = 0; + yyn = 0; + yynerrs = 0; + yyerrflag = 0; + yychar = YYEMPTY; + yystate = 0; + +#if YYPURE + memset(&yystack, 0, sizeof(yystack)); +#endif + + if (yystack.s_base == NULL && yygrowstack(&yystack) == YYENOMEM) goto yyoverflow; + yystack.s_mark = yystack.s_base; + yystack.l_mark = yystack.l_base; + yystate = 0; + *yystack.s_mark = 0; + +yyloop: + if ((yyn = yydefred[yystate]) != 0) goto yyreduce; + if (yychar < 0) + { + yychar = YYLEX; + if (yychar < 0) yychar = YYEOF; +#if YYDEBUG + if (yydebug) + { + if ((yys = yyname[YYTRANSLATE(yychar)]) == NULL) yys = yyname[YYUNDFTOKEN]; + printf("%sdebug: state %d, reading %d (%s)\n", + YYPREFIX, yystate, yychar, yys); + } +#endif + } + if (((yyn = yysindex[yystate]) != 0) && (yyn += yychar) >= 0 && + yyn <= YYTABLESIZE && yycheck[yyn] == (YYINT) yychar) + { +#if YYDEBUG + if (yydebug) + printf("%sdebug: state %d, shifting to state %d\n", + YYPREFIX, yystate, yytable[yyn]); +#endif + if (yystack.s_mark >= yystack.s_last && yygrowstack(&yystack) == YYENOMEM) goto yyoverflow; + yystate = yytable[yyn]; + *++yystack.s_mark = yytable[yyn]; + *++yystack.l_mark = yylval; + yychar = YYEMPTY; + if (yyerrflag > 0) --yyerrflag; + goto yyloop; + } + if (((yyn = yyrindex[yystate]) != 0) && (yyn += yychar) >= 0 && + yyn <= YYTABLESIZE && yycheck[yyn] == (YYINT) yychar) + { + yyn = yytable[yyn]; + goto yyreduce; + } + if (yyerrflag != 0) goto yyinrecovery; + + YYERROR_CALL("syntax error"); + + goto yyerrlab; /* redundant goto avoids 'unused label' warning */ +yyerrlab: + ++yynerrs; + +yyinrecovery: + if (yyerrflag < 3) + { + yyerrflag = 3; + for (;;) + { + if (((yyn = yysindex[*yystack.s_mark]) != 0) && (yyn += YYERRCODE) >= 0 && + yyn <= YYTABLESIZE && yycheck[yyn] == (YYINT) YYERRCODE) + { +#if YYDEBUG + if (yydebug) + printf("%sdebug: state %d, error recovery shifting\ + to state %d\n", YYPREFIX, *yystack.s_mark, yytable[yyn]); +#endif + if (yystack.s_mark >= yystack.s_last && yygrowstack(&yystack) == YYENOMEM) goto yyoverflow; + yystate = yytable[yyn]; + *++yystack.s_mark = yytable[yyn]; + *++yystack.l_mark = yylval; + goto yyloop; + } + else + { +#if YYDEBUG + if (yydebug) + printf("%sdebug: error recovery discarding state %d\n", + YYPREFIX, *yystack.s_mark); +#endif + if (yystack.s_mark <= yystack.s_base) goto yyabort; + --yystack.s_mark; + --yystack.l_mark; + } + } + } + else + { + if (yychar == YYEOF) goto yyabort; +#if YYDEBUG + if (yydebug) + { + if ((yys = yyname[YYTRANSLATE(yychar)]) == NULL) yys = yyname[YYUNDFTOKEN]; + printf("%sdebug: state %d, error recovery discards token %d (%s)\n", + YYPREFIX, yystate, yychar, yys); + } +#endif + yychar = YYEMPTY; + goto yyloop; + } + +yyreduce: +#if YYDEBUG + if (yydebug) + printf("%sdebug: state %d, reducing by rule %d (%s)\n", + YYPREFIX, yystate, yyn, yyrule[yyn]); +#endif + yym = yylen[yyn]; + if (yym > 0) + yyval = yystack.l_mark[1-yym]; + else + memset(&yyval, 0, sizeof yyval); + + switch (yyn) + { +case 5: +#line 85 "usr.bin/doas/parse.y" + { + struct rule *r; + r = calloc(1, sizeof(*r)); + if (!r) + errx(1, "can't allocate rule"); + r->action = yystack.l_mark[-3].action; + r->options = yystack.l_mark[-3].options; + r->envlist = yystack.l_mark[-3].envlist; + r->ident = yystack.l_mark[-2].str; + r->target = yystack.l_mark[-1].str; + r->cmd = yystack.l_mark[0].cmd; + r->cmdargs = yystack.l_mark[0].cmdargs; + if (nrules == maxrules) { + if (maxrules == 0) + maxrules = 63; + else + maxrules *= 2; + if (!(rules = reallocarray(rules, maxrules, + sizeof(*rules)))) + errx(1, "can't allocate rules"); + } + rules[nrules++] = r; + } +break; +case 6: +#line 109 "usr.bin/doas/parse.y" + { + yyval.action = PERMIT; + yyval.options = yystack.l_mark[0].options; + yyval.envlist = yystack.l_mark[0].envlist; + } +break; +case 7: +#line 113 "usr.bin/doas/parse.y" + { + yyval.action = DENY; + yyval.options = 0; + yyval.envlist = NULL; + } +break; +case 8: +#line 119 "usr.bin/doas/parse.y" + { + yyval.options = 0; + yyval.envlist = NULL; + } +break; +case 9: +#line 122 "usr.bin/doas/parse.y" + { + yyval.options = yystack.l_mark[-1].options | yystack.l_mark[0].options; + yyval.envlist = yystack.l_mark[-1].envlist; + if ((yyval.options & (NOPASS|PERSIST)) == (NOPASS|PERSIST)) { + yyerror("can't combine nopass and persist"); + YYERROR; + } + if (yystack.l_mark[0].envlist) { + if (yyval.envlist) { + yyerror("can't have two setenv sections"); + YYERROR; + } else + yyval.envlist = yystack.l_mark[0].envlist; + } + } +break; +case 10: +#line 137 "usr.bin/doas/parse.y" + { + yyval.options = NOPASS; + yyval.envlist = NULL; + } +break; +case 11: +#line 140 "usr.bin/doas/parse.y" + { + yyval.options = PERSIST; + yyval.envlist = NULL; + } +break; +case 12: +#line 143 "usr.bin/doas/parse.y" + { + yyval.options = KEEPENV; + yyval.envlist = NULL; + } +break; +case 13: +#line 146 "usr.bin/doas/parse.y" + { + yyval.options = 0; + yyval.envlist = yystack.l_mark[-1].strlist; + } +break; +case 14: +#line 151 "usr.bin/doas/parse.y" + { + if (!(yyval.strlist = calloc(1, sizeof(char *)))) + errx(1, "can't allocate strlist"); + } +break; +case 15: +#line 154 "usr.bin/doas/parse.y" + { + int nstr = arraylen(yystack.l_mark[-1].strlist); + if (!(yyval.strlist = reallocarray(yystack.l_mark[-1].strlist, nstr + 2, + sizeof(char *)))) + errx(1, "can't allocate strlist"); + yyval.strlist[nstr] = yystack.l_mark[0].str; + yyval.strlist[nstr + 1] = NULL; + } +break; +case 16: +#line 164 "usr.bin/doas/parse.y" + { + yyval.str = yystack.l_mark[0].str; + } +break; +case 17: +#line 168 "usr.bin/doas/parse.y" + { + yyval.str = NULL; + } +break; +case 18: +#line 170 "usr.bin/doas/parse.y" + { + yyval.str = yystack.l_mark[0].str; + } +break; +case 19: +#line 174 "usr.bin/doas/parse.y" + { + yyval.cmd = NULL; + yyval.cmdargs = NULL; + } +break; +case 20: +#line 177 "usr.bin/doas/parse.y" + { + yyval.cmd = yystack.l_mark[-1].str; + yyval.cmdargs = yystack.l_mark[0].cmdargs; + } +break; +case 21: +#line 182 "usr.bin/doas/parse.y" + { + yyval.cmdargs = NULL; + } +break; +case 22: +#line 184 "usr.bin/doas/parse.y" + { + yyval.cmdargs = yystack.l_mark[0].strlist; + } +break; +#line 812 "usr.bin/doas/parse.c" + } + yystack.s_mark -= yym; + yystate = *yystack.s_mark; + yystack.l_mark -= yym; + yym = yylhs[yyn]; + if (yystate == 0 && yym == 0) + { +#if YYDEBUG + if (yydebug) + printf("%sdebug: after reduction, shifting from state 0 to\ + state %d\n", YYPREFIX, YYFINAL); +#endif + yystate = YYFINAL; + *++yystack.s_mark = YYFINAL; + *++yystack.l_mark = yyval; + if (yychar < 0) + { + yychar = YYLEX; + if (yychar < 0) yychar = YYEOF; +#if YYDEBUG + if (yydebug) + { + if ((yys = yyname[YYTRANSLATE(yychar)]) == NULL) yys = yyname[YYUNDFTOKEN]; + printf("%sdebug: state %d, reading %d (%s)\n", + YYPREFIX, YYFINAL, yychar, yys); + } +#endif + } + if (yychar == YYEOF) goto yyaccept; + goto yyloop; + } + if (((yyn = yygindex[yym]) != 0) && (yyn += yystate) >= 0 && + yyn <= YYTABLESIZE && yycheck[yyn] == (YYINT) yystate) + yystate = yytable[yyn]; + else + yystate = yydgoto[yym]; +#if YYDEBUG + if (yydebug) + printf("%sdebug: after reduction, shifting from state %d \ +to state %d\n", YYPREFIX, *yystack.s_mark, yystate); +#endif + if (yystack.s_mark >= yystack.s_last && yygrowstack(&yystack) == YYENOMEM) goto yyoverflow; + *++yystack.s_mark = (YYINT) yystate; + *++yystack.l_mark = yyval; + goto yyloop; + +yyoverflow: + YYERROR_CALL("yacc stack overflow"); + +yyabort: + yyfreestack(&yystack); + return (1); + +yyaccept: + yyfreestack(&yystack); + return (0); +} diff --git a/usr.bin/doas/parse.tab.h b/usr.bin/doas/parse.tab.h new file mode 100644 index 0000000..dfa6b41 --- /dev/null +++ b/usr.bin/doas/parse.tab.h @@ -0,0 +1,10 @@ +#define TPERMIT 257 +#define TDENY 258 +#define TAS 259 +#define TCMD 260 +#define TARGS 261 +#define TNOPASS 262 +#define TPERSIST 263 +#define TKEEPENV 264 +#define TSETENV 265 +#define TSTRING 266 diff --git a/usr.bin/doas/parse.y b/usr.bin/doas/parse.y new file mode 100644 index 0000000..d1f698c --- /dev/null +++ b/usr.bin/doas/parse.y @@ -0,0 +1,343 @@ +/* $OpenBSD: parse.y,v 1.27 2018/07/11 07:39:22 krw Exp $ */ +/* + * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +%{ +#include <sys/types.h> +#include <ctype.h> +#include <unistd.h> +#include <stdlib.h> +#include <stdint.h> +#include <stdarg.h> +#include <stdio.h> +#include <string.h> +#include <err.h> + +#include "doas.h" + +typedef struct { + union { + struct { + int action; + int options; + const char *cmd; + const char **cmdargs; + const char **envlist; + }; + const char **strlist; + const char *str; + }; + int lineno; + int colno; +} yystype; +#define YYSTYPE yystype + +FILE *yyfp; + +struct rule **rules; +int nrules; +static int maxrules; + +int parse_errors = 0; + +static void yyerror(const char *, ...); +static int yylex(void); + +static size_t +arraylen(const char **arr) +{ + size_t cnt = 0; + + while (*arr) { + cnt++; + arr++; + } + return cnt; +} + +%} + +%token TPERMIT TDENY TAS TCMD TARGS +%token TNOPASS TPERSIST TKEEPENV TSETENV +%token TSTRING + +%% + +grammar: /* empty */ + | grammar '\n' + | grammar rule '\n' + | error '\n' + ; + +rule: action ident target cmd { + struct rule *r; + r = calloc(1, sizeof(*r)); + if (!r) + errx(1, "can't allocate rule"); + r->action = $1.action; + r->options = $1.options; + r->envlist = $1.envlist; + r->ident = $2.str; + r->target = $3.str; + r->cmd = $4.cmd; + r->cmdargs = $4.cmdargs; + if (nrules == maxrules) { + if (maxrules == 0) + maxrules = 63; + else + maxrules *= 2; + if (!(rules = reallocarray(rules, maxrules, + sizeof(*rules)))) + errx(1, "can't allocate rules"); + } + rules[nrules++] = r; + } ; + +action: TPERMIT options { + $$.action = PERMIT; + $$.options = $2.options; + $$.envlist = $2.envlist; + } | TDENY { + $$.action = DENY; + $$.options = 0; + $$.envlist = NULL; + } ; + +options: /* none */ { + $$.options = 0; + $$.envlist = NULL; + } | options option { + $$.options = $1.options | $2.options; + $$.envlist = $1.envlist; + if (($$.options & (NOPASS|PERSIST)) == (NOPASS|PERSIST)) { + yyerror("can't combine nopass and persist"); + YYERROR; + } + if ($2.envlist) { + if ($$.envlist) { + yyerror("can't have two setenv sections"); + YYERROR; + } else + $$.envlist = $2.envlist; + } + } ; +option: TNOPASS { + $$.options = NOPASS; + $$.envlist = NULL; + } | TPERSIST { + $$.options = PERSIST; + $$.envlist = NULL; + } | TKEEPENV { + $$.options = KEEPENV; + $$.envlist = NULL; + } | TSETENV '{' strlist '}' { + $$.options = 0; + $$.envlist = $3.strlist; + } ; + +strlist: /* empty */ { + if (!($$.strlist = calloc(1, sizeof(char *)))) + errx(1, "can't allocate strlist"); + } | strlist TSTRING { + int nstr = arraylen($1.strlist); + if (!($$.strlist = reallocarray($1.strlist, nstr + 2, + sizeof(char *)))) + errx(1, "can't allocate strlist"); + $$.strlist[nstr] = $2.str; + $$.strlist[nstr + 1] = NULL; + } ; + + +ident: TSTRING { + $$.str = $1.str; + } ; + +target: /* optional */ { + $$.str = NULL; + } | TAS TSTRING { + $$.str = $2.str; + } ; + +cmd: /* optional */ { + $$.cmd = NULL; + $$.cmdargs = NULL; + } | TCMD TSTRING args { + $$.cmd = $2.str; + $$.cmdargs = $3.cmdargs; + } ; + +args: /* empty */ { + $$.cmdargs = NULL; + } | TARGS strlist { + $$.cmdargs = $2.strlist; + } ; + +%% + +void +yyerror(const char *fmt, ...) +{ + va_list va; + + fprintf(stderr, "doas: "); + va_start(va, fmt); + vfprintf(stderr, fmt, va); + va_end(va); + fprintf(stderr, " at line %d\n", yylval.lineno + 1); + parse_errors++; +} + +static struct keyword { + const char *word; + int token; +} keywords[] = { + { "deny", TDENY }, + { "permit", TPERMIT }, + { "as", TAS }, + { "cmd", TCMD }, + { "args", TARGS }, + { "nopass", TNOPASS }, + { "persist", TPERSIST }, + { "keepenv", TKEEPENV }, + { "setenv", TSETENV }, +}; + +int +yylex(void) +{ + char buf[1024], *ebuf, *p, *str; + int i, c, quotes = 0, escape = 0, qpos = -1, nonkw = 0; + + p = buf; + ebuf = buf + sizeof(buf); + +repeat: + /* skip whitespace first */ + for (c = getc(yyfp); c == ' ' || c == '\t'; c = getc(yyfp)) + yylval.colno++; + + /* check for special one-character constructions */ + switch (c) { + case '\n': + yylval.colno = 0; + yylval.lineno++; + /* FALLTHROUGH */ + case '{': + case '}': + return c; + case '#': + /* skip comments; NUL is allowed; no continuation */ + while ((c = getc(yyfp)) != '\n') + if (c == EOF) + goto eof; + yylval.colno = 0; + yylval.lineno++; + return c; + case EOF: + goto eof; + } + + /* parsing next word */ + for (;; c = getc(yyfp), yylval.colno++) { + switch (c) { + case '\0': + yyerror("unallowed character NUL in column %d", + yylval.colno + 1); + escape = 0; + continue; + case '\\': + escape = !escape; + if (escape) + continue; + break; + case '\n': + if (quotes) + yyerror("unterminated quotes in column %d", + qpos + 1); + if (escape) { + nonkw = 1; + escape = 0; + yylval.colno = 0; + yylval.lineno++; + continue; + } + goto eow; + case EOF: + if (escape) + yyerror("unterminated escape in column %d", + yylval.colno); + if (quotes) + yyerror("unterminated quotes in column %d", + qpos + 1); + goto eow; + /* FALLTHROUGH */ + case '{': + case '}': + case '#': + case ' ': + case '\t': + if (!escape && !quotes) + goto eow; + break; + case '"': + if (!escape) { + quotes = !quotes; + if (quotes) { + nonkw = 1; + qpos = yylval.colno; + } + continue; + } + } + *p++ = c; + if (p == ebuf) { + yyerror("too long line"); + p = buf; + } + escape = 0; + } + +eow: + *p = 0; + if (c != EOF) + ungetc(c, yyfp); + if (p == buf) { + /* + * There could be a number of reasons for empty buffer, + * and we handle all of them here, to avoid cluttering + * the main loop. + */ + if (c == EOF) + goto eof; + else if (qpos == -1) /* accept, e.g., empty args: cmd foo args "" */ + goto repeat; + } + if (!nonkw) { + for (i = 0; i < sizeof(keywords) / sizeof(keywords[0]); i++) { + if (strcmp(buf, keywords[i].word) == 0) + return keywords[i].token; + } + } + if ((str = strdup(buf)) == NULL) + err(1, "%s", __func__); + yylval.str = str; + return TSTRING; + +eof: + if (ferror(yyfp)) + yyerror("input error reading config"); + return 0; +} diff --git a/usr.bin/doas/persist.c b/usr.bin/doas/persist.c new file mode 100644 index 0000000..4ad1bf1 --- /dev/null +++ b/usr.bin/doas/persist.c @@ -0,0 +1,133 @@ +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <time.h> +#include <unistd.h> + +#include "doas.h" + +#define PERSIST_DIR "/run/doas" +#define PERSIST_TIMEOUT 5 * 60 + +static int +ttyid(dev_t *tty) +{ + int fd, i; + char buf[BUFSIZ], *p; + ssize_t n; + + fd = open("/proc/self/stat", O_RDONLY); + if (fd == -1) + return -1; + n = read(fd, buf, sizeof(buf) - 1); + if (n >= 0) + buf[n] = '\0'; + /* check that we read the whole file */ + n = read(fd, buf, 1); + close(fd); + if (n != 0) + return -1; + p = strrchr(buf, ')'); + if (!p) + return -1; + ++p; + /* ttr_nr is the 5th field after executable name, so skip the next 4 */ + for (i = 0; i < 4; ++i) { + p = strchr(++p, ' '); + if (!p) + return -1; + } + *tty = strtol(p, &p, 10); + if (*p != ' ') + return -1; + return 0; +} + +static int +persistpath(char *buf, size_t len) +{ + dev_t tty; + int n; + + if (ttyid(&tty) < 0) + return -1; + n = snprintf(buf, len, PERSIST_DIR "/%ju-%ju", (uintmax_t)getuid(), (uintmax_t)tty); + if (n < 0 || n >= (int)len) + return -1; + return 0; +} + +int +openpersist(int *valid) +{ + char path[256]; + struct stat st; + struct timespec ts; + int fd; + + if (stat(PERSIST_DIR, &st) < 0) { + if (errno != ENOENT) + return -1; + if (mkdir(PERSIST_DIR, 0700) < 0) + return -1; + } else if (st.st_uid != 0 || st.st_mode != (S_IFDIR | 0700)) { + return -1; + } + if (persistpath(path, sizeof(path)) < 0) + return -1; + fd = open(path, O_RDONLY); + if (fd == -1) { + char tmp[256]; + struct timespec ts[2] = { { .tv_nsec = UTIME_OMIT }, { 0 } }; + int n; + + n = snprintf(tmp, sizeof(tmp), PERSIST_DIR "/.tmp-%d", getpid()); + if (n < 0 || n >= (int)sizeof(tmp)) + return -1; + fd = open(tmp, O_RDONLY | O_CREAT | O_EXCL, 0); + if (fd == -1) + return -1; + if (futimens(fd, ts) < 0 || rename(tmp, path) < 0) { + close(fd); + unlink(tmp); + return -1; + } + *valid = 0; + } else { + *valid = clock_gettime(CLOCK_BOOTTIME, &ts) == 0 && + fstat(fd, &st) == 0 && + (ts.tv_sec < st.st_mtim.tv_sec || + (ts.tv_sec == st.st_mtim.tv_sec && ts.tv_nsec < st.st_mtim.tv_nsec)) && + st.st_mtime - ts.tv_sec <= PERSIST_TIMEOUT; + } + return fd; +} + +int +setpersist(int fd) +{ + struct timespec times[2]; + + if (clock_gettime(CLOCK_BOOTTIME, ×[1]) < 0) + return -1; + times[0].tv_nsec = UTIME_OMIT; + times[1].tv_sec += PERSIST_TIMEOUT; + return futimens(fd, times); +} + +int +clearpersist(void) +{ + char path[256]; + + if (persistpath(path, sizeof(path)) < 0) + return -1; + if (unlink(path) < 0 && errno != ENOENT) + return -1; + return 0; +} |