/*

 * Copyright (c) 2009, Sun Microsystems, Inc.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 * - Redistributions of source code must retain the above copyright notice,

 *   this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright notice,

 *   this list of conditions and the following disclaimer in the documentation

 *   and/or other materials provided with the distribution.

 * - Neither the name of Sun Microsystems, Inc. nor the names of its

 *   contributors may be used to endorse or promote products derived

 *   from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGE.

 */

/*

 * Copyright (c) 1989 by Sun Microsystems, Inc.

 */

#include <pthread.h>

#include <reentrant.h>

#include <stdio.h>

#include <errno.h>

#include <netconfig.h>

#include <stddef.h>

#include <stdlib.h>

#include <string.h>

#include <rpc/rpc.h>

#include <unistd.h>

#include "rpc_com.h"

/*

 * The five library routines in this file provide application access to the

 * system network configuration database, /etc/netconfig.  In addition to the

 * netconfig database and the routines for accessing it, the environment

 * variable NETPATH and its corresponding routines in getnetpath.c may also be

 * used to specify the network transport to be used.

 */

/*

 * netconfig errors

 */

#define NC_NONETCONFIG	ENOENT

#define NC_NOMEM	ENOMEM

#define NC_NOTINIT	EINVAL	    /* setnetconfig was not called first */

#define NC_BADFILE	EBADF	    /* format for netconfig file is bad */

#define NC_NOTFOUND	ENOPROTOOPT /* specified netid was not found */

/*

 * semantics as strings (should be in netconfig.h)

 */

#define NC_TPI_CLTS_S	    "tpi_clts"

#define	NC_TPI_COTS_S	    "tpi_cots"

#define	NC_TPI_COTS_ORD_S   "tpi_cots_ord"

#define	NC_TPI_RAW_S        "tpi_raw"

/*

 * flags as characters (also should be in netconfig.h)

 */

#define	NC_NOFLAG_C	'-'

#define	NC_VISIBLE_C	'v'

#define	NC_BROADCAST_C	'b'

/*

 * Character used to indicate there is no name-to-address lookup library

 */

#define NC_NOLOOKUP	"-"

static const char * const _nc_errors[] = {

    "Netconfig database not found",

    "Not enough memory",

    "Not initialized",

    "Netconfig database has invalid format",

    "Netid not found in netconfig database"

};

struct netconfig_info {

    int		eof;	/* all entries has been read */

    int		ref;	/* # of times setnetconfig() has been called */

    struct netconfig_list	*head;	/* head of the list */

    struct netconfig_list	*tail;	/* last of the list */

};

struct netconfig_list {

    char			*linep;	/* hold line read from netconfig */

    struct netconfig		*ncp;

    struct netconfig_list	*next;

};

struct netconfig_vars {

    int   valid;	/* token that indicates a valid netconfig_vars */

    int   flag;		/* first time flag */

    struct netconfig_list *nc_configs;  /* pointer to the current netconfig entry */

};

#define NC_VALID	0xfeed

#define NC_STORAGE	0xf00d

#define NC_INVALID	0

static int *__nc_error(void);

static int parse_ncp(char *, struct netconfig *);

static struct netconfig *dup_ncp(struct netconfig *);

static FILE *nc_file;		/* for netconfig db */

static struct netconfig_info	ni = { 0, 0, NULL, NULL};

extern pthread_mutex_t nc_db_lock;

#define MAXNETCONFIGLINE    1000

static int *

__nc_error()

{

	static pthread_mutex_t nc_lock = PTHREAD_MUTEX_INITIALIZER;

	extern thread_key_t nc_key;

	static int nc_error = 0;

	int error, *nc_addr;

	/*

	 * Use the static `nc_error' if we are the main thread

	 * (including non-threaded programs), or if an allocation

	 * fails.

	 */

	if (nc_key == KEY_INITIALIZER) {

		error = 0;

		mutex_lock(&nc_lock);

		if (nc_key == KEY_INITIALIZER)

			error = thr_keycreate(&nc_key, free);

		mutex_unlock(&nc_lock);

		if (error)

			return (&nc_error);

	}

	if ((nc_addr = (int *)thr_getspecific(nc_key)) == NULL) {

		if((nc_addr = (int *)malloc(sizeof (int))) == NULL)

			return (&nc_error);

		if (thr_setspecific(nc_key, (void *) nc_addr) != 0) {

			if (nc_addr)

				free(nc_addr);

			return (&nc_error);

		}

		*nc_addr = 0;

	}

	return (nc_addr);

}

#define nc_error        (*(__nc_error()))

/*

 * A call to setnetconfig() establishes a /etc/netconfig "session".  A session

 * "handle" is returned on a successful call.  At the start of a session (after

 * a call to setnetconfig()) searches through the /etc/netconfig database will

 * proceed from the start of the file.  The session handle must be passed to

 * getnetconfig() to parse the file.  Each call to getnetconfig() using the

 * current handle will process one subsequent entry in /etc/netconfig.

 * setnetconfig() must be called before the first call to getnetconfig().

 * (Handles are used to allow for nested calls to setnetpath()).

 *

 * A new session is established with each call to setnetconfig(), with a new

 * handle being returned on each call.  Previously established sessions remain

 * active until endnetconfig() is called with that session's handle as an

 * argument.

 *

 * setnetconfig() need *not* be called before a call to getnetconfigent().

 * setnetconfig() returns a NULL pointer on failure (for example, if

 * the netconfig database is not present).

 */

void *

setnetconfig()

{

    struct netconfig_vars *nc_vars;

    if ((nc_vars = (struct netconfig_vars *)malloc(sizeof

		(struct netconfig_vars))) == NULL) {

	return(NULL);

    }

    /*

     * For multiple calls, i.e. nc_file is not NULL, we just return the

     * handle without reopening the netconfig db.

     */

    mutex_lock(&nc_db_lock);

    ni.ref++;

    if ((nc_file != NULL) || (nc_file = fopen(NETCONFIG, "r")) != NULL) {

	nc_vars->valid = NC_VALID;

	nc_vars->flag = 0;

	nc_vars->nc_configs = ni.head;

	mutex_unlock(&nc_db_lock);

	return ((void *)nc_vars);

    }

    ni.ref--;

    mutex_unlock(&nc_db_lock);

    nc_error = NC_NONETCONFIG;

    free(nc_vars);

    return (NULL);

}

/*

 * When first called, getnetconfig() returns a pointer to the first entry in

 * the netconfig database, formatted as a struct netconfig.  On each subsequent

 * call, getnetconfig() returns a pointer to the next entry in the database.

 * getnetconfig() can thus be used to search the entire netconfig file.

 * getnetconfig() returns NULL at end of file.

 */

struct netconfig *

getnetconfig(handlep)

void *handlep;

{

    struct netconfig_vars *ncp = (struct netconfig_vars *)handlep;

    char *stringp;		/* tmp string pointer */

    struct netconfig_list	*list;

    struct netconfig *np;

    struct netconfig *result;

    /*

     * Verify that handle is valid

     */

    mutex_lock(&nc_db_lock);

    if (ncp == NULL || nc_file == NULL) {

	nc_error = NC_NOTINIT;

	mutex_unlock(&nc_db_lock);

	return (NULL);

    }

    switch (ncp->valid) {

    case NC_VALID:

	/*

	 * If entry has already been read into the list,

	 * we return the entry in the linked list.

	 * If this is the first time call, check if there are any entries in

	 * linked list.  If no entries, we need to read the netconfig db.

	 * If we have been here and the next entry is there, we just return

	 * it.

	 */

	if (ncp->flag == 0) {	/* first time */

	    ncp->flag = 1;

	    ncp->nc_configs = ni.head;

	    if (ncp->nc_configs != NULL)	/* entry already exist */ {

		mutex_unlock(&nc_db_lock);

		return(ncp->nc_configs->ncp);

		}

	}

	else if (ncp->nc_configs != NULL && ncp->nc_configs->next != NULL) {

	    ncp->nc_configs = ncp->nc_configs->next;

	    mutex_unlock(&nc_db_lock);

	    return(ncp->nc_configs->ncp);

	}

	/*

	 * If we cannot find the entry in the list and is end of file,

	 * we give up.

	 */

	if (ni.eof == 1) {

	    mutex_unlock(&nc_db_lock);

	    return(NULL);

	}

	break;

    default:

	nc_error = NC_NOTINIT;

	mutex_unlock(&nc_db_lock);

	return (NULL);

    }

    stringp = (char *) malloc(MAXNETCONFIGLINE);

    if (stringp == NULL) {

    mutex_unlock(&nc_db_lock);

    return (NULL);

    }

#ifdef MEM_CHK

    if (malloc_verify() == 0) {

	fprintf(stderr, "memory heap corrupted in getnetconfig\n");

	exit(1);

    }

#endif

    /*

     * Read a line from netconfig file.

     */

    do {

	if (fgets(stringp, MAXNETCONFIGLINE, nc_file) == NULL) {

	    free(stringp);

	    ni.eof = 1;

	    mutex_unlock(&nc_db_lock);

	    return (NULL);

        }

    } while (*stringp == '#');

    list = (struct netconfig_list *) malloc(sizeof (struct netconfig_list));

    if (list == NULL) {

    	free(stringp);

		mutex_unlock(&nc_db_lock);

    	return(NULL);

    }

    np = (struct netconfig *) malloc(sizeof (struct netconfig));

    if (np == NULL) {

    	free(stringp);

		free(list);

		mutex_unlock(&nc_db_lock);

    	return(NULL);

    }

    list->ncp = np;

    list->next = NULL;

    list->ncp->nc_lookups = NULL;

    list->linep = stringp;

    if (parse_ncp(stringp, list->ncp) == -1) {

	free(stringp);

	free(np);

	free(list);

	mutex_unlock(&nc_db_lock);

	return (NULL);

    }

    else {

	/*

	 * If this is the first entry that's been read, it is the head of

	 * the list.  If not, put the entry at the end of the list.

	 * Reposition the current pointer of the handle to the last entry

	 * in the list.

	 */

	if (ni.head == NULL) {	/* first entry */

	    ni.head = ni.tail = list;

	}

    	else {

    	    ni.tail->next = list;

    	    ni.tail = ni.tail->next;

    	}

	ncp->nc_configs = ni.tail;

	result = ni.tail->ncp;

	mutex_unlock(&nc_db_lock);

	return result;

    }

}

/*

 * endnetconfig() may be called to "unbind" or "close" the netconfig database

 * when processing is complete, releasing resources for reuse.  endnetconfig()

 * may not be called before setnetconfig().  endnetconfig() returns 0 on

 * success and -1 on failure (for example, if setnetconfig() was not called

 * previously).

 */

int

endnetconfig(handlep)

void *handlep;

{

    struct netconfig_vars *nc_handlep = (struct netconfig_vars *)handlep;

    struct netconfig_list *q, *p;

    /*

     * Verify that handle is valid

     */

    if (nc_handlep == NULL || (nc_handlep->valid != NC_VALID &&

	    nc_handlep->valid != NC_STORAGE)) {

	nc_error = NC_NOTINIT;

	return (-1);

    }

    /*

     * Return 0 if anyone still needs it.

     */

    nc_handlep->valid = NC_INVALID;

    nc_handlep->flag = 0;

    nc_handlep->nc_configs = NULL;

    mutex_lock(&nc_db_lock);

    if (--ni.ref > 0) {

	mutex_unlock(&nc_db_lock);

	free(nc_handlep);

	return(0);

    }

    /*

     * Noone needs these entries anymore, then frees them.

     * Make sure all info in netconfig_info structure has been reinitialized.

     */

    q = p = ni.head;

    ni.eof = ni.ref = 0;

    ni.head = NULL;

    ni.tail = NULL;

    while (q) {

	p = q->next;

	if (q->ncp->nc_lookups != NULL) free(q->ncp->nc_lookups);

	free(q->ncp);

	free(q->linep);

	free(q);

	q = p;

    }

    free(nc_handlep);

    if(nc_file != NULL) {

        fclose(nc_file);

    }

    nc_file = NULL;

    mutex_unlock(&nc_db_lock);

    return (0);

}

/*

 * getnetconfigent(netid) returns a pointer to the struct netconfig structure

 * corresponding to netid.  It returns NULL if netid is invalid (that is, does

 * not name an entry in the netconfig database).  It returns NULL and sets

 * errno in case of failure (for example, if the netconfig database cannot be

 * opened).

 */

struct netconfig *

getnetconfigent(netid)

	const char *netid;

{

    FILE *file;		/* NETCONFIG db's file pointer */

    char *linep;	/* holds current netconfig line */

    char *stringp;	/* temporary string pointer */

    struct netconfig *ncp = NULL;   /* returned value */

    struct netconfig_list *list;	/* pointer to cache list */

    nc_error = NC_NOTFOUND;	/* default error. */

    if (netid == NULL || strlen(netid) == 0) {

	return (NULL);

    }

    if (strcmp(netid, "unix") == 0) {

	fprintf(stderr, "The local transport is called \"unix\" ");

	fprintf(stderr, "in /etc/netconfig.\n");

	fprintf(stderr, "Please change this to \"local\" manually ");

	fprintf(stderr, "or run mergemaster(8).\n");

	fprintf(stderr, "See UPDATING entry 20021216 for details.\n");

	fprintf(stderr, "Continuing in 10 seconds\n\n");

	fprintf(stderr, "This warning will be removed 20030301\n");

	sleep(10);

    }

    /*

     * Look up table if the entries have already been read and parsed in

     * getnetconfig(), then copy this entry into a buffer and return it.

     * If we cannot find the entry in the current list and there are more

     * entries in the netconfig db that has not been read, we then read the

     * db and try find the match netid.

     * If all the netconfig db has been read and placed into the list and

     * there is no match for the netid, return NULL.

     */

    mutex_lock(&nc_db_lock);

    if (ni.head != NULL) {

	for (list = ni.head; list; list = list->next) {

	    if (strcmp(list->ncp->nc_netid, netid) == 0) {

			ncp = dup_ncp(list->ncp);

			mutex_unlock(&nc_db_lock);

			return ncp;

	    }

	}

        if (ni.eof == 1) {	/* that's all the entries */

	    	mutex_unlock(&nc_db_lock);

	    	return(NULL);

        }

    }

    mutex_unlock(&nc_db_lock);

    if ((file = fopen(NETCONFIG, "r")) == NULL) {

	nc_error = NC_NONETCONFIG;

	return (NULL);

    }

    if ((linep = malloc(MAXNETCONFIGLINE)) == NULL) {

	fclose(file);

	nc_error = NC_NOMEM;

	return (NULL);

    }

    do {

	ptrdiff_t len;

	char *tmpp;	/* tmp string pointer */

	do {

	    if ((stringp = fgets(linep, MAXNETCONFIGLINE, file)) == NULL) {

		break;

	    }

	} while (*stringp == '#');

	if (stringp == NULL) {	    /* eof */

	    break;

	}

	if ((tmpp = strpbrk(stringp, "\t ")) == NULL) {	/* can't parse file */

	    nc_error = NC_BADFILE;

	    break;

	}

	if (strlen(netid) == (size_t) (len = tmpp - stringp) &&	/* a match */

		strncmp(stringp, netid, (size_t)len) == 0) {

	    if ((ncp = (struct netconfig *)

		    malloc(sizeof (struct netconfig))) == NULL) {

		break;

	    }

	    ncp->nc_lookups = NULL;

	    if (parse_ncp(linep, ncp) == -1) {

		free(ncp);

		ncp = NULL;

	    }

	    break;

	}

    } while (stringp != NULL);

    if (ncp == NULL) {

	free(linep);

    }

    fclose(file);

    return(ncp);

}

/*

 * freenetconfigent(netconfigp) frees the netconfig structure pointed to by

 * netconfigp (previously returned by getnetconfigent()).

 */

void

freenetconfigent(netconfigp)

	struct netconfig *netconfigp;

{

    if (netconfigp != NULL) {

	free(netconfigp->nc_netid);	/* holds all netconfigp's strings */

	if (netconfigp->nc_lookups != NULL)

	    free(netconfigp->nc_lookups);

	free(netconfigp);

    }

    return;

}

/*

 * Parse line and stuff it in a struct netconfig

 * Typical line might look like:

 *	udp tpi_cots vb inet udp /dev/udp /usr/lib/ip.so,/usr/local/ip.so

 *

 * We return -1 if any of the tokens don't parse, or malloc fails.

 *

 * Note that we modify stringp (putting NULLs after tokens) and

 * we set the ncp's string field pointers to point to these tokens within

 * stringp.

 */

static int

parse_ncp(stringp, ncp)

char *stringp;		/* string to parse */

struct netconfig *ncp;	/* where to put results */

{

    char    *tokenp;	/* for processing tokens */

    char    *lasts;

    nc_error = NC_BADFILE;	/* nearly anything that breaks is for this reason */

    stringp[strlen(stringp)-1] = '\0';	/* get rid of newline */

    /* netid */

    if ((ncp->nc_netid = strtok_r(stringp, "\t ", &lasts)) == NULL) {

	return (-1);

    }

    /* semantics */

    if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {

	return (-1);

    }

    if (strcmp(tokenp, NC_TPI_COTS_ORD_S) == 0)

	ncp->nc_semantics = NC_TPI_COTS_ORD;

    else if (strcmp(tokenp, NC_TPI_COTS_S) == 0)

	ncp->nc_semantics = NC_TPI_COTS;

    else if (strcmp(tokenp, NC_TPI_CLTS_S) == 0)

	ncp->nc_semantics = NC_TPI_CLTS;

    else if (strcmp(tokenp, NC_TPI_RAW_S) == 0)

	ncp->nc_semantics = NC_TPI_RAW;

    else

	return (-1);

    /* flags */

    if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {

	return (-1);

    }

    for (ncp->nc_flag = NC_NOFLAG; *tokenp != '\0';

	    tokenp++) {

	switch (*tokenp) {

	case NC_NOFLAG_C:

	    break;

	case NC_VISIBLE_C:

	    ncp->nc_flag |= NC_VISIBLE;

	    break;

	case NC_BROADCAST_C:

	    ncp->nc_flag |= NC_BROADCAST;

	    break;

	default:

	    return (-1);

	}

    }

    /* protocol family */

    if ((ncp->nc_protofmly = strtok_r(NULL, "\t ", &lasts)) == NULL) {

	return (-1);

    }

    /* protocol name */

    if ((ncp->nc_proto = strtok_r(NULL, "\t ", &lasts)) == NULL) {

	return (-1);

    }

    /* network device */

    if ((ncp->nc_device = strtok_r(NULL, "\t ", &lasts)) == NULL) {

	return (-1);

    }

    if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {

	return (-1);

    }

    if (strcmp(tokenp, NC_NOLOOKUP) == 0) {

	ncp->nc_nlookups = 0;

	ncp->nc_lookups = NULL;

    } else {

	char *cp;	    /* tmp string */

	if (ncp->nc_lookups != NULL)	/* from last visit */

	    free(ncp->nc_lookups);

	/* preallocate one string pointer */

	ncp->nc_lookups = (char **)malloc(sizeof (char *));

	ncp->nc_nlookups = 0;

	while ((cp = tokenp) != NULL) {

	    tokenp = _get_next_token(cp, ',');

	    ncp->nc_lookups[(size_t)ncp->nc_nlookups++] = cp;

	    ncp->nc_lookups = (char **)realloc(ncp->nc_lookups,

		(size_t)(ncp->nc_nlookups+1) *sizeof(char *));	/* for next loop */

	}

    }

    return (0);

}

/*

 * Returns a string describing the reason for failure.

 */

char *

nc_sperror()

{

    const char *message;

    switch(nc_error) {

    case NC_NONETCONFIG:

	message = _nc_errors[0];

	break;

    case NC_NOMEM:

	message = _nc_errors[1];

	break;

    case NC_NOTINIT:

	message = _nc_errors[2];

	break;

    case NC_BADFILE:

	message = _nc_errors[3];

	break;

    case NC_NOTFOUND:

	message = _nc_errors[4];

	break;

    default:

	message = "Unknown network selection error";

    }

    /* LINTED const castaway */

    return ((char *)message);

}

/*

 * Prints a message onto standard error describing the reason for failure.

 */

void

nc_perror(s)

	const char *s;

{

    fprintf(stderr, "%s: %s\n", s, nc_sperror());

}

/*

 * Duplicates the matched netconfig buffer.

 */

static struct netconfig *

dup_ncp(ncp)

struct netconfig	*ncp;

{

    struct netconfig	*p;

    char	*tmp;

    char	*t;

    u_int	i;

    if ((tmp=malloc(MAXNETCONFIGLINE)) == NULL)

	return(NULL);

    if ((p=(struct netconfig *)malloc(sizeof(struct netconfig))) == NULL) {

	free(tmp);

	return(NULL);

    }

    /*

     * First we dup all the data from matched netconfig buffer.  Then we

     * adjust some of the member pointer to a pre-allocated buffer where

     * contains part of the data.

     * To follow the convention used in parse_ncp(), we store all the

     * necessary information in the pre-allocated buffer and let each

     * of the netconfig char pointer member point to the right address

     * in the buffer.

     */

    *p = *ncp;

    p->nc_netid = (char *)strcpy(tmp,ncp->nc_netid);

    t = strchr(tmp, 0) + 1;

    p->nc_protofmly = (char *)strcpy(t,ncp->nc_protofmly);

    t = strchr(t, 0) + 1;

    p->nc_proto = (char *)strcpy(t,ncp->nc_proto);

    t = strchr(t, 0) + 1;

    p->nc_device = (char *)strcpy(t,ncp->nc_device);

    p->nc_lookups = (char **)malloc((size_t)(p->nc_nlookups+1) * sizeof(char *));

    if (p->nc_lookups == NULL) {

	free(p);

	free(tmp);

	return(NULL);

    }

    for (i=0; i < p->nc_nlookups; i++) {

	t = strchr(t, 0) + 1;

	p->nc_lookups[i] = (char *)strcpy(t,ncp->nc_lookups[i]);

    }

    return(p);

}