libipsecutil/common/algs.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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <ipsec_util.h>
#include <stdlib.h>
#include <strings.h>
#include <netdb.h>
#include <fcntl.h>
#include <unistd.h>
#include <libintl.h>
#include <errno.h>

static char *preamble =
"# /etc/inet/ipsecalgs output from ipsecalgs(1m)\n"
"#\n"
"# DO NOT EDIT OR PARSE THIS FILE!\n"
"#\n"
"# Use the ipsecalgs(1m) command to change the contents of this file.\n"
"# The algorithm descriptions contained in this file are synchronised to the\n"
"# kernel with ipsecalgs -s, the kernel validates the entries at this point."
"\n\n"
"# PROTO|protocol-id|protocol-name|exec-mode\n"
"##  NOTE:  Some protocol numbers are well-known and defined in <netdb.h>\n\n"
"# ALG|protocol-id|alg-id|name,name,...|ef-id| \n"
"#        {default/}{key,key..}or{key-key,inc}|block_size or MAC-size|\n"
"#        [parameter,parameter..]|[flags]\n\n"
"#\n"
"## Note:   Parameters and flags only apply to certain algorithms.\n\n";

#define CFG_PERMS S_IRUSR | S_IRGRP | S_IROTH   /* Perms 0444. */
#define CFG_OWNER 0 /* root */
#define CFG_GROUP 1 /* "other" */

/*
 * write_new_algfile() helper macros to check for write errors.
 */

#define FPRINTF_ERR(fcall) if ((fcall) < 0) {   \
    rc = LIBIPSEC_ALGS_DIAG_ALGSFILEWRITE;  \
    goto bail;              \
}

#define FPUT_ERR(fcall) if ((fcall) == EOF) {   \
    rc = LIBIPSEC_ALGS_DIAG_ALGSFILEWRITE;  \
    goto bail;              \
}

/*
 * Helper macros to start and finish a list of entries that were added
 * as part of a package installation.
 */

#define PKG_SEC_START(pkgname, doing_pkg, cur_pkg) {        \
    (void) strcpy((cur_pkg), (pkgname));            \
    FPRINTF_ERR(fprintf(f, "%s%s\n",            \
        LIBIPSEC_ALGS_LINE_PKGSTART, (cur_pkg)));       \
    (doing_pkg) = B_TRUE;                   \
}

#define PKG_SEC_END(doing_pkg, cur_pkg) {           \
    if (doing_pkg) {                    \
        FPRINTF_ERR(fprintf(f, "%s%s\n",        \
            LIBIPSEC_ALGS_LINE_PKGEND, (cur_pkg))); \
        (doing_pkg) = B_FALSE;              \
    }                           \
}

/*
 * Take a zero-terminated int array and print int1,int2...,intN.
 * If zero-only, then print a single '0'.
 * Returns 0 on success, -1 if an error occurred while writing to
 * the specified file.
 */
int
list_ints(FILE *f, int *floater)
{
    boolean_t executed = B_FALSE;

    while (*floater != 0) {
        executed = B_TRUE;
        if (fprintf(f, "%d", *floater) < 0)
            return (-1);
        if (*(++floater) != 0)
            if (fputc(',', f) == EOF)
                return (-1);
    }

    if (!executed)
        if (fputc('0', f) == EOF)
            return (-1);

    return (0);
}

/*
 * If the specified algorithm was defined within a package section, i.e.
 * between the lines "# Start <pkgname>" and "# End <pkgname>", returns
 * the value of <pkgname>.
 */
static char *
alg_has_pkg(ipsec_proto_t *proto, struct ipsecalgent *alg)
{
    int i;

    if (proto->proto_algs_pkgs == NULL)
        return (NULL);

    for (i = 0; i < proto->proto_algs_npkgs; i++)
        if (proto->proto_algs_pkgs[i].alg_num == alg->a_alg_num)
            return (proto->proto_algs_pkgs[i].pkg_name);

    return (NULL);
}

/*
 * Writes the package start/end delimiters according to the package
 * name associated with the current protocol or algorithm, and
 * the state of the packaging information already written to the file.
 * Called by write_new_algfile(). Returns 0 on success, one of the
 * LIBIPSEC_DIAG codes on failure.
 */
static int
pkg_section(FILE *f, char *pkg_name, boolean_t *doing_pkg, char *cur_pkg)
{
    int rc = 0;

    if (pkg_name != NULL) {
        /* protocol or algorithm is associated with a package */
        if (!*doing_pkg) {
            /* start of a new package section */
            PKG_SEC_START(pkg_name, *doing_pkg, cur_pkg);
        } else {
            /* already in a package section */
            if (strcmp(pkg_name, cur_pkg) != 0) {
                /* different package name */
                PKG_SEC_END(*doing_pkg, cur_pkg);
                PKG_SEC_START(pkg_name, *doing_pkg, cur_pkg);
            }
        }
    } else if (*doing_pkg) {
        /* in a package section when the entry isn't */
        PKG_SEC_END(*doing_pkg, cur_pkg);
    }
bail:
    return (rc);
}

/*
 * Given a list of protocols and number, write them to a new algorithm file.
 * This function takes num_protos + num_protos * dois-per-alg operations.
 * Also free the protocol structure.
 *
 * Note that no locking spans the read/update/write phases that can be
 * used by callers of this routine. This could cause this function to suffer
 * from the "lost update" problem. Since updates to the IPsec protocols
 * and algorithm tables are very infrequent, this should not be a issue in
 * practice.
 */
static int
write_new_algfile(ipsec_proto_t *protos, int num_protos)
{
    FILE *f;
    int fd, i, j, k;
    int rc = 0;
    struct ipsecalgent *alg;
    char cur_pkg[1024];
    boolean_t doing_pkg = B_FALSE;
    char *alg_pkg;
    char tmp_name_template[] = INET_IPSECALGSPATH "ipsecalgsXXXXXX";
    char *tmp_name;

    /*
     * In order to avoid potentially corrupting the configuration
     * file on file system failure, write the new configuration info
     * to a temporary file which is then renamed to the configuration
     * file (INET_IPSECALGSFILE.)
     */
    tmp_name = mktemp(tmp_name_template);

    fd = open(tmp_name, O_WRONLY|O_CREAT|O_EXCL, CFG_PERMS);
    if (fd == -1) {
        rc = LIBIPSEC_ALGS_DIAG_ALGSFILEOPEN;
        goto bail;
    }

    f = fdopen(fd, "w");
    if (f == NULL) {
        (void) close(fd);
        rc = LIBIPSEC_ALGS_DIAG_ALGSFILEFDOPEN;
        goto bail;
    }

    FPUT_ERR(fputs(preamble, f));

    /* Write protocol entries. */
    for (i = 0; i < num_protos; i++) {

        /* add package section delimiters if needed */
        rc = pkg_section(f, protos[i].proto_pkg, &doing_pkg, cur_pkg);
        if (rc != 0)
            goto bail;

        FPRINTF_ERR(fprintf(f, "%s%d|%s|",
            LIBIPSEC_ALGS_LINE_PROTO,
            protos[i].proto_num, protos[i].proto_name));
        switch (protos[i].proto_exec_mode) {
        case LIBIPSEC_ALGS_EXEC_SYNC:
            FPRINTF_ERR(fprintf(f, "sync\n"));
            break;
        case LIBIPSEC_ALGS_EXEC_ASYNC:
            FPRINTF_ERR(fprintf(f, "async\n"));
            break;
        }
    }

    /* terminate the package section for the protocols if needed */
    PKG_SEC_END(doing_pkg, cur_pkg);

    FPUT_ERR(fputs("\n", f));

    /* Write algorithm entries. */

    for (i = 0; i < num_protos; i++) {
        for (j = 0; j < protos[i].proto_numalgs; j++) {
            alg = protos[i].proto_algs[j];

            /* add package section delimiters if needed */
            alg_pkg = alg_has_pkg(&protos[i], alg);
            rc = pkg_section(f, alg_pkg, &doing_pkg, cur_pkg);
            if (rc != 0)
                goto bail;

            /* protocol and algorithm numbers */
            FPRINTF_ERR(fprintf(f, "%s%d|%d|",
                LIBIPSEC_ALGS_LINE_ALG,
                alg->a_proto_num, alg->a_alg_num));

            /* algorithm names */
            for (k = 0; alg->a_names[k] != NULL; k++) {
                FPRINTF_ERR(fprintf(f, "%s", alg->a_names[k]));
                if (alg->a_names[k+1] != NULL)
                    FPRINTF_ERR(fprintf(f, ","));
            }

            /* mechanism name */
            FPRINTF_ERR(fprintf(f, "|%s|", alg->a_mech_name));

            /* key sizes */
            if (alg->a_key_increment == 0) {
                /* key sizes defined by enumeration */
                if (list_ints(f, alg->a_key_sizes) == -1) {
                    rc = LIBIPSEC_ALGS_DIAG_ALGSFILEWRITE;
                    goto bail;
                }
            } else {
                /* key sizes defined by range */
                FPRINTF_ERR(fprintf(f, "%d/%d-%d,%d",
                    alg->a_key_sizes[0], alg->a_key_sizes[1],
                    alg->a_key_sizes[2], alg->a_key_increment));
            }
            FPUT_ERR(fputc('|', f));

            /* block sizes */
            if (list_ints(f, alg->a_block_sizes) == -1) {
                rc = LIBIPSEC_ALGS_DIAG_ALGSFILEWRITE;
                goto bail;
            }
            FPUT_ERR(fputc('|', f));

            /*
             * Some algorithms require extra parameters, these
             * are stored in an array. For algorithms that don't
             * need these parameters, or flags (below), these
             * extra fields in the ipsecalgs file must contain a
             * zero. This fuction will get called if a algorithm
             * entry is added, at this point the extra fields will
             * be added to the file.
             */
            if (list_ints(f, alg->a_mech_params) == -1) {
                rc = LIBIPSEC_ALGS_DIAG_ALGSFILEWRITE;
                goto bail;
            }
            /* flags */
            FPRINTF_ERR(fprintf(f, "|%d\n", alg->a_alg_flags));
        }
    }

    /* terminate the package section for the algorithms if needed */
    PKG_SEC_END(doing_pkg, cur_pkg);

    if (fchmod(fd, CFG_PERMS) == -1) {
        rc = LIBIPSEC_ALGS_DIAG_ALGSFILECHMOD;
        goto bail;
    }
    if (fchown(fd, CFG_OWNER, CFG_GROUP) == -1) {
        rc = LIBIPSEC_ALGS_DIAG_ALGSFILECHOWN;
        goto bail;
    }
    if (fclose(f) == EOF) {
        rc = LIBIPSEC_ALGS_DIAG_ALGSFILECLOSE;
        goto bail;
    }

    if (rename(tmp_name, INET_IPSECALGSFILE) == -1)
        rc = LIBIPSEC_ALGS_DIAG_ALGSFILERENAME;

bail:
    _clean_trash(protos, num_protos);
    return (rc);
}

/*
 * Return a pointer to the protocol entry corresponding to the specified
 * protocol num proto_num. Also builds the list of currently defined
 * protocols.
 */
static ipsec_proto_t *
proto_setup(ipsec_proto_t **protos, int *num_protos, int proto_num,
    boolean_t cleanup)
{
    int i;
    ipsec_proto_t *current_proto, *ret_proto = NULL;

    _build_internal_algs(protos, num_protos);

    if (*protos == NULL)
        return (NULL);

    for (i = 0; i < *num_protos; i++) {
        current_proto = (*protos) + i;
        if (current_proto->proto_num == proto_num) {
            ret_proto = current_proto;
            break;
        }
    }

    if (ret_proto == NULL) {
        if (cleanup)
            _clean_trash(*protos, *num_protos);
        /* else caller wants parsed /etc/inet/ipsecalgs anyway */
    }

    return (ret_proto);
}

/*
 * Delete the first found algorithm of the specified protocol which
 * has the same name as the one specified by alg_name. Deletion of
 * the entry takes place only if the delete_it flag is set. If an
 * entry was found, return B_TRUE, otherwise return B_FALSE.
 */
static boolean_t
delipsecalgbyname_common(const char *name, ipsec_proto_t *proto,
    boolean_t delete_it)
{
    int i;
    char **name_check;
    boolean_t found_match = B_FALSE;

    for (i = 0; i < proto->proto_numalgs; i++) {
        if (!found_match) {
            for (name_check =
                proto->proto_algs[i]->a_names;
                *name_check != NULL; name_check++) {
                /*
                 * Can use strcmp because the algorithm names
                 * are bound.
                 */
                if (strcmp(*name_check, name) == 0) {
                    found_match = B_TRUE;
                    if (!delete_it)
                        return (found_match);
                    freeipsecalgent(proto->proto_algs[i]);
                    break;
                }
            }
        } else {
            proto->proto_algs[i - 1] = proto->proto_algs[i];
        }
    }

    if (found_match)
        proto->proto_numalgs--;

    return (found_match);
}

/*
 * Returns B_TRUE if the specified 0-terminated lists of key or
 * block sizes match, B_FALSE otherwise.
 */
static boolean_t
sizes_match(int *a1, int *a2)
{
    int i;

    for (i = 0; (a1[i] != 0) && (a2[i] != 0); i++) {
        if (a1[i] != a2[i])
            return (B_FALSE);
    }
    if ((a1[i] != 0) || (a2[i] != 0))
        return (B_FALSE);

    return (B_TRUE);
}

/*
 * Returns B_TRUE if an _exact_ equivalent of the specified algorithm
 * already exists, B_FALSE otherwise.
 */
static boolean_t
ipsecalg_exists(struct ipsecalgent *newbie, ipsec_proto_t *proto)
{
    struct ipsecalgent *curalg;
    char **curname, **newbiename;
    int i;
    boolean_t match;

    for (i = 0; i < proto->proto_numalgs; i++) {
        curalg = proto->proto_algs[i];

        if (curalg->a_alg_num != newbie->a_alg_num)
            continue;

        if (curalg->a_key_increment != newbie->a_key_increment)
            continue;

        if (strcmp(curalg->a_mech_name, newbie->a_mech_name) != 0)
            continue;

        curname = curalg->a_names;
        newbiename = newbie->a_names;
        match = B_TRUE;
        while ((*curname != NULL) && (*newbiename != NULL) && match) {
            match = (strcmp(*curname, *newbiename) == 0);
            curname++;
            newbiename++;
        }
        if (!match || (*curname != NULL) || (*newbiename != NULL))
            continue;

        if (!sizes_match(curalg->a_block_sizes, newbie->a_block_sizes))
            continue;

        if (!sizes_match(curalg->a_key_sizes, newbie->a_key_sizes))
            continue;

        /* we found an exact match */
        return (B_TRUE);
    }

    return (B_FALSE);
}

/*
 * Add a new algorithm to the /etc/inet/ipsecalgs file.  Caller must free
 * or otherwise address "newbie".
 */
int
addipsecalg(struct ipsecalgent *newbie, uint_t flags)
{
    ipsec_proto_t *protos, *current_proto;
    struct ipsecalgent *clone, **holder;
    int num_protos, i;
    char **name_check;
    boolean_t forced_add = (flags & LIBIPSEC_ALGS_ADD_FORCE) != 0;
    boolean_t found_match;

    if ((current_proto = proto_setup(&protos, &num_protos,
        newbie->a_proto_num, B_TRUE)) == NULL)
        return (LIBIPSEC_ALGS_DIAG_UNKN_PROTO);

    /*
     * If an algorithm that matches _exactly_ the new algorithm
     * already exists, we're done.
     */
    if (ipsecalg_exists(newbie, current_proto))
        return (0);

    /*
     * We don't allow a new algorithm to be created if one of
     * its names is already defined for an existing algorithm,
     * unless the operation is forced, in which case existing
     * algorithm entries that conflict with the new one are
     * deleted.
     */
    for (name_check = newbie->a_names; *name_check != NULL; name_check++) {
        found_match = delipsecalgbyname_common(*name_check,
            current_proto, forced_add);
        if (found_match && !forced_add) {
            /*
             * Duplicate entry found, but the addition was
             * not forced.
             */
            _clean_trash(protos, num_protos);
            return (LIBIPSEC_ALGS_DIAG_ALG_EXISTS);
        }
    }

    for (i = 0; i < current_proto->proto_numalgs; i++) {
        if (current_proto->proto_algs[i]->a_alg_num ==
            newbie->a_alg_num) {
            /*
             * An algorithm with the same protocol number
             * and algorithm number already exists. Fail
             * addition unless the operation is forced.
             */
            if (flags & LIBIPSEC_ALGS_ADD_FORCE) {
                clone = _duplicate_alg(newbie);
                if (clone != NULL) {
                    freeipsecalgent(
                        current_proto->proto_algs[i]);
                    current_proto->proto_algs[i] = clone;
                    return (write_new_algfile(protos,
                        num_protos));
                } else {
                    _clean_trash(protos, num_protos);
                    return (LIBIPSEC_ALGS_DIAG_NOMEM);
                }
            } else {
                _clean_trash(protos, num_protos);
                return (LIBIPSEC_ALGS_DIAG_ALG_EXISTS);
            }
        }
    }

    /* append the new algorithm */
    holder = realloc(current_proto->proto_algs,
        sizeof (struct ipsecalgent *) * (i + 1));
    if (holder == NULL) {
        _clean_trash(protos, num_protos);
        return (LIBIPSEC_ALGS_DIAG_NOMEM);
    }
    clone = _duplicate_alg(newbie);
    if (clone == NULL) {
        free(holder);
        _clean_trash(protos, num_protos);
        return (LIBIPSEC_ALGS_DIAG_NOMEM);
    }
    current_proto->proto_numalgs++;
    current_proto->proto_algs = holder;
    current_proto->proto_algs[i] = clone;
    return (write_new_algfile(protos, num_protos));
}

/*
 * Delete an algorithm by name & protocol number from /etc/inet/ipsecalgs.
 * Only deletes the first encountered instance.
 */
int
delipsecalgbyname(const char *name, int proto_num)
{
    ipsec_proto_t *protos, *current_proto;
    int num_protos;

    if ((current_proto = proto_setup(&protos, &num_protos, proto_num,
        B_TRUE)) == NULL)
        return (LIBIPSEC_ALGS_DIAG_UNKN_PROTO);

    if (delipsecalgbyname_common(name, current_proto, B_TRUE))
        return (write_new_algfile(protos, num_protos));

    _clean_trash(protos, num_protos);
    return (LIBIPSEC_ALGS_DIAG_UNKN_ALG);
}

/*
 * Delete an algorithm by num + protocol num from /etc/inet/ipsecalgs.
 */
int
delipsecalgbynum(int alg_num, int proto_num)
{
    ipsec_proto_t *protos, *current_proto;
    int i, num_protos;
    boolean_t found_match = B_FALSE;

    if ((current_proto = proto_setup(&protos, &num_protos, proto_num,
        B_TRUE)) == NULL)
        return (LIBIPSEC_ALGS_DIAG_UNKN_PROTO);

    for (i = 0; i < current_proto->proto_numalgs; i++) {
        if (!found_match) {
            if (current_proto->proto_algs[i]->a_alg_num ==
                alg_num) {
                found_match = B_TRUE;
                freeipsecalgent(current_proto->proto_algs[i]);
            }
        } else {
            current_proto->proto_algs[i - 1] =
                current_proto->proto_algs[i];
        }
    }

    if (found_match) {
        current_proto->proto_numalgs--;
        return (write_new_algfile(protos, num_protos));
    }

    _clean_trash(protos, num_protos);
    return (LIBIPSEC_ALGS_DIAG_UNKN_ALG);
}

/*
 * Remove the specified protocol entry from the list of protocols.
 */
static void
delipsecproto_common(ipsec_proto_t *protos, int num_protos,
    ipsec_proto_t *proto)
{
    int i;

    /* free protocol storage */
    free(proto->proto_name);
    for (i = 0; i < proto->proto_numalgs; i++)
        freeipsecalgent(proto->proto_algs[i]);

    /* remove from list of prototocols */
    for (i = (proto - protos + 1); i < num_protos; i++)
        protos[i - 1] = protos[i];
}

/*
 * Add an IPsec protocol to /etc/inet/ipsecalgs.
 */
int
addipsecproto(const char *proto_name, int proto_num,
    ipsecalgs_exec_mode_t proto_exec_mode, uint_t flags)
{
    ipsec_proto_t *protos, *current_proto, *new_proto;
    int i, num_protos;

    /*
     * NOTE:If build_internal_algs returns NULL for any
     *  reason, we will end up clobbering /etc/inet/ipsecalgs!
     */

    current_proto = proto_setup(&protos, &num_protos, proto_num, B_FALSE);

    /* check for protocol with duplicate id */
    if (current_proto != NULL) {
        if ((strcmp(proto_name, current_proto->proto_name) == 0) &&
            (proto_exec_mode == current_proto->proto_exec_mode)) {
            /*
             * The current protocol being added matches
             * exactly an existing protocol, we're done.
             */
            return (0);
        }
        if (!(flags & LIBIPSEC_ALGS_ADD_FORCE))
            return (LIBIPSEC_ALGS_DIAG_PROTO_EXISTS);
        delipsecproto_common(protos, num_protos--, current_proto);
    }

    /* check for protocol with duplicate name */
    for (i = 0; i < num_protos; i++) {
        if (strcmp(protos[i].proto_name, proto_name) == 0) {
            if (!(flags & LIBIPSEC_ALGS_ADD_FORCE))
                return (LIBIPSEC_ALGS_DIAG_PROTO_EXISTS);
            delipsecproto_common(protos, num_protos--, &protos[i]);
            break;
        }
    }

    /* add new protocol */
    num_protos++;
    new_proto = realloc(protos, num_protos *
        sizeof (ipsec_proto_t));
    if (new_proto == NULL) {
        _clean_trash(protos, num_protos - 1);
        return (LIBIPSEC_ALGS_DIAG_NOMEM);
    }
    protos = new_proto;
    new_proto += (num_protos - 1);

    /* initialize protocol entry */
    new_proto->proto_num = proto_num;
    new_proto->proto_numalgs = 0;
    new_proto->proto_algs = NULL;
    new_proto->proto_name = strdup(proto_name);
    if (new_proto->proto_name == NULL) {
        _clean_trash(protos, num_protos);
        return (LIBIPSEC_ALGS_DIAG_NOMEM);
    }
    new_proto->proto_pkg = NULL;
    new_proto->proto_algs_pkgs = NULL;
    new_proto->proto_algs_npkgs = 0;
    new_proto->proto_exec_mode = proto_exec_mode;

    return (write_new_algfile(protos, num_protos));
}

/*
 * Delete an IPsec protocol entry from /etc/inet/ipsecalgs.  This also
 * nukes the associated algorithms.
 */
int
delipsecprotobynum(int proto_num)
{
    ipsec_proto_t *protos, *current_proto;
    int num_protos;

    if ((current_proto = proto_setup(&protos, &num_protos, proto_num,
        B_TRUE)) == NULL)
        return (LIBIPSEC_ALGS_DIAG_UNKN_PROTO);

    delipsecproto_common(protos, num_protos--, current_proto);

    return (write_new_algfile(protos, num_protos));
}

int
delipsecprotobyname(const char *proto_name)
{
    int proto_num;

    proto_num = getipsecprotobyname(proto_name);
    if (proto_num == -1)
        return (LIBIPSEC_ALGS_DIAG_UNKN_PROTO);

    return (delipsecprotobynum(proto_num));
}

/*
 * Implement these in libnsl since these are read-only operations.
 */
int *
getipsecprotos(int *nentries)
{
    return (_real_getipsecprotos(nentries));
}

int *
getipsecalgs(int *nentries, int proto_num)
{
    return (_real_getipsecalgs(nentries, proto_num));
}

const char *
ipsecalgs_diag(int diag)
{
    switch (diag) {
    case LIBIPSEC_ALGS_DIAG_ALG_EXISTS:
        return (dgettext(TEXT_DOMAIN, "Algorithm already exists"));
    case LIBIPSEC_ALGS_DIAG_PROTO_EXISTS:
        return (dgettext(TEXT_DOMAIN, "Protocol already exists"));
    case LIBIPSEC_ALGS_DIAG_UNKN_PROTO:
        return (dgettext(TEXT_DOMAIN, "Unknown protocol"));
    case LIBIPSEC_ALGS_DIAG_UNKN_ALG:
        return (dgettext(TEXT_DOMAIN, "Unknown algorithm"));
    case LIBIPSEC_ALGS_DIAG_NOMEM:
        return (dgettext(TEXT_DOMAIN, "Out of memory"));
    case LIBIPSEC_ALGS_DIAG_ALGSFILEOPEN:
        return (dgettext(TEXT_DOMAIN, "open() failed"));
    case LIBIPSEC_ALGS_DIAG_ALGSFILEFDOPEN:
        return (dgettext(TEXT_DOMAIN, "fdopen() failed"));
    case LIBIPSEC_ALGS_DIAG_ALGSFILELOCK:
        return (dgettext(TEXT_DOMAIN, "lockf() failed"));
    case LIBIPSEC_ALGS_DIAG_ALGSFILERENAME:
        return (dgettext(TEXT_DOMAIN, "rename() failed"));
    case LIBIPSEC_ALGS_DIAG_ALGSFILEWRITE:
        return (dgettext(TEXT_DOMAIN, "write to file failed"));
    case LIBIPSEC_ALGS_DIAG_ALGSFILECHMOD:
        return (dgettext(TEXT_DOMAIN, "chmod() failed"));
    case LIBIPSEC_ALGS_DIAG_ALGSFILECHOWN:
        return (dgettext(TEXT_DOMAIN, "chown() failed"));
    case LIBIPSEC_ALGS_DIAG_ALGSFILECLOSE:
        return (dgettext(TEXT_DOMAIN, "close() failed"));
    default:
        return (dgettext(TEXT_DOMAIN, "failed"));
    }
}

/*
 * Get the execution mode corresponding to the specified protocol.
 * Returns 0 on success, one of the LIBIPSEC_ALGS_DIAG_* values on
 * failure.
 */
int
ipsecproto_get_exec_mode(int proto_num, ipsecalgs_exec_mode_t *exec_mode)
{
    ipsec_proto_t *protos, *current_proto;
    int num_protos;

    if ((current_proto = proto_setup(&protos, &num_protos, proto_num,
        B_TRUE)) == NULL)
        return (LIBIPSEC_ALGS_DIAG_UNKN_PROTO);

    *exec_mode = current_proto->proto_exec_mode;

    _clean_trash(protos, num_protos);
    return (0);
}

/*
 * Set the execution mode of the specified protocol. Returns 0 on success,
 * or one of the LIBIPSEC_ALGS_DIAG_* values on failure.
 */
int
ipsecproto_set_exec_mode(int proto_num, ipsecalgs_exec_mode_t exec_mode)
{
    ipsec_proto_t *protos, *current_proto;
    int num_protos;

    if ((current_proto = proto_setup(&protos, &num_protos, proto_num,
        B_TRUE)) == NULL)
        return (LIBIPSEC_ALGS_DIAG_UNKN_PROTO);

    current_proto->proto_exec_mode = exec_mode;

    return (write_new_algfile(protos, num_protos));
}