ptools/pcred/pcred.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <errno.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <limits.h>
#include <sys/types.h>
#include <pwd.h>
#include <grp.h>
#include <libproc.h>

extern int _getgroupsbymember(const char *, gid_t[], int, int);

static int look(char *);
static int perr(char *);

static void usage(void);
static void initcred(void);

static char *command;
static char *procname;

static char *user;
static char *group;
static char *grplst;
static char *login;

static boolean_t all = B_FALSE;
static boolean_t doset = B_FALSE;
static int ngrp = -1;
static gid_t *groups;
static long ngroups_max;

static uid_t uid = (uid_t)-1;
static gid_t gid = (gid_t)-1;

int
main(int argc, char **argv)
{
    int rc = 0;
    int c;
    struct rlimit rlim;

    if ((command = strrchr(argv[0], '/')) != NULL)
        command++;
    else
        command = argv[0];

    if ((ngroups_max = sysconf(_SC_NGROUPS_MAX)) < 0)
        return (perr("sysconf(_SC_NGROUPS_MAX)"));

    opterr = 0;

    while ((c = getopt(argc, argv, "au:g:l:G:")) != EOF) {
        switch (c) {
        case 'a':
            all = B_TRUE;
            break;
        case 'u':
            user = optarg;
            doset = B_TRUE;
            break;
        case 'g':
            group = optarg;
            doset = B_TRUE;
            break;
        case 'G':
            grplst = optarg;
            doset = B_TRUE;
            break;
        case 'l':
            login = optarg;
            doset = B_TRUE;
            break;
        default:
            usage();
            /*NOTREACHED*/
        }
    }
    if (login != NULL && (user != NULL || group != NULL || grplst != NULL))
        usage();

    if (all && doset)
        usage();

    argc -= optind;
    argv += optind;

    if (argc == 0)
        usage();

    if (doset)
        initcred();

    /*
     * Make sure we'll have enough file descriptors to handle a target
     * that has many many mappings.
     */
    if (getrlimit(RLIMIT_NOFILE, &rlim) == 0) {
        rlim.rlim_cur = rlim.rlim_max;
        (void) setrlimit(RLIMIT_NOFILE, &rlim);
        (void) enable_extended_FILE_stdio(-1, -1);
    }

    while (argc-- > 0)
        rc += look(*argv++);

    return (rc > 255 ? 255 : rc);
}

static void
credupdate(prcred_t *pcr)
{
    if (uid != (uid_t)-1)
        pcr->pr_euid = pcr->pr_ruid = pcr->pr_suid = uid;
    if (gid != (gid_t)-1)
        pcr->pr_egid = pcr->pr_rgid = pcr->pr_sgid = gid;
    if (ngrp >= 0) {

        pcr->pr_ngroups = ngrp;

        (void) memcpy(pcr->pr_groups, groups, ngrp * sizeof (gid_t));
    }
}

static int
look(char *arg)
{
    struct ps_prochandle *Pr;
    static prcred_t *prcred = NULL;
    int gcode;

    procname = arg;     /* for perr() */

    if (prcred == NULL) {
        prcred = malloc(sizeof (prcred_t) +
            (ngroups_max - 1) * sizeof (gid_t));
        if (prcred == NULL) {
            (void) perr("malloc");
            exit(1);
        }
    }

    if ((Pr = proc_arg_grab(arg, doset ? PR_ARG_PIDS : PR_ARG_ANY,
        PGRAB_RETAIN | PGRAB_FORCE | (doset ? 0 : PGRAB_RDONLY) |
        PGRAB_NOSTOP, &gcode)) == NULL) {
        (void) fprintf(stderr, "%s: cannot examine %s: %s\n",
            command, arg, Pgrab_error(gcode));
        return (1);
    }

    if (Pcred(Pr, prcred, ngroups_max) == -1) {
        (void) perr("getcred");
        Prelease(Pr, 0);
        return (1);
    }

    if (doset) {
        credupdate(prcred);
        if (Psetcred(Pr, prcred) != 0) {
            (void) perr("setcred");
            Prelease(Pr, 0);
            return (1);
        }
        Prelease(Pr, 0);
        return (0);
    }

    if (Pstate(Pr) == PS_DEAD)
        (void) printf("core of %d:\t", (int)Pstatus(Pr)->pr_pid);
    else
        (void) printf("%d:\t", (int)Pstatus(Pr)->pr_pid);

    if (!all &&
        prcred->pr_euid == prcred->pr_ruid &&
        prcred->pr_ruid == prcred->pr_suid)
        (void) printf("e/r/suid=%u  ", prcred->pr_euid);
    else
        (void) printf("euid=%u ruid=%u suid=%u  ",
            prcred->pr_euid, prcred->pr_ruid, prcred->pr_suid);

    if (!all &&
        prcred->pr_egid == prcred->pr_rgid &&
        prcred->pr_rgid == prcred->pr_sgid)
        (void) printf("e/r/sgid=%u\n", prcred->pr_egid);
    else
        (void) printf("egid=%u rgid=%u sgid=%u\n",
            prcred->pr_egid, prcred->pr_rgid, prcred->pr_sgid);

    if (prcred->pr_ngroups != 0 &&
        (all || prcred->pr_ngroups != 1 ||
        prcred->pr_groups[0] != prcred->pr_rgid)) {
        int i;

        (void) printf("\tgroups:");
        for (i = 0; i < prcred->pr_ngroups; i++)
            (void) printf(" %u", prcred->pr_groups[i]);
        (void) printf("\n");
    }

    Prelease(Pr, 0);
    return (0);
}

static int
perr(char *s)
{
    if (s)
        (void) fprintf(stderr, "%s: ", procname);
    else
        s = procname;
    perror(s);
    return (1);
}

static void
usage(void)
{
    (void) fprintf(stderr, "usage:\t%s [-a] { pid | core } ...\n"
        "\t%s [-u user] [-g group] [-G groups] pid ...\n"
        "\t%s -l login pid ...\n"
        "  (report or modify process credentials)\n",
        command, command, command);
    exit(2);
}


static uint32_t
str2id(const char *str)
{
    unsigned long res;
    char *p;

    errno = 0;
    res = strtoul(str, &p, 0);
    if (p == str || *p != '\0' || errno != 0)
        return ((uint32_t)-1);
    else
        return ((uint32_t)res);
}

static gid_t
str2gid(const char *grnam)
{
    struct group *grp = getgrnam(grnam);
    gid_t res;

    if (grp == NULL) {
        res = (gid_t)str2id(grnam);
        if (res == (gid_t)-1) {
            (void) fprintf(stderr, "%s: %s: unknown group"
                " or bad gid\n",
                command, grnam);
            exit(1);
        }
    } else {
        res = grp->gr_gid;
    }
    return (res);
}

static void
initcred(void)
{
    struct passwd *pwd;

    if ((groups = malloc(ngroups_max * sizeof (gid_t))) == NULL) {
        (void) perr("malloc");
        exit(1);
    }

    if (login != NULL) {
        pwd = getpwnam(login);

        if (pwd == NULL) {
            (void) fprintf(stderr, "%s: %s: unknown user\n",
                command, login);
            exit(1);
        }
        uid = pwd->pw_uid;
        gid = pwd->pw_gid;

        groups[0] = gid;

        ngrp = _getgroupsbymember(login, groups, (int)ngroups_max, 1);
    }

    if (user != NULL) {
        pwd = getpwnam(user);
        if (pwd == NULL) {
            uid = (uid_t)str2id(user);
            if (uid == (uid_t)-1) {
                (void) fprintf(stderr, "%s: %s: unknown user"
                    " or bad uid\n",
                    command, user);
                exit(1);
            }
        } else {
            uid = pwd->pw_uid;
        }
    }

    if (group != NULL)
        gid = str2gid(group);

    if (grplst != NULL) {
        char *cgrp;

        ngrp = 0;

        while ((cgrp = strtok(grplst, ",")) != NULL) {

            if (ngrp >= ngroups_max) {
                (void) fprintf(stderr, "%s: Too many groups\n",
                    command);
                exit(1);
            }
            groups[ngrp++] = str2gid(cgrp);

            /* For iterations of strtok */
            grplst = NULL;
        }
    }
}