mirror_frr/lib/ptm_lib.c

/* PTM Library
 * Copyright (C) 2015 Cumulus Networks, Inc.
 *
 * This file is part of Quagga.
 *
 * Quagga is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * Quagga is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Quagga; see the file COPYING.  If not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stddef.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <errno.h>
#include <sys/socket.h>
#include "csv.h"
#include "ptm_lib.h"

#define DEBUG_E 0
#define DEBUG_V 0

#define ERRLOG(fmt, ...) \
  do { if (DEBUG_E) fprintf(stderr, "%s:%d:%s(): " fmt, __FILE__, \
			    __LINE__, __func__, ##__VA_ARGS__); } while (0)

#define DLOG(fmt, ...) \
  do { if (DEBUG_V) fprintf(stderr, "%s:%d:%s(): " fmt, __FILE__, \
			    __LINE__, __func__, ##__VA_ARGS__); } while (0)

typedef struct ptm_lib_msg_ctxt_s {
    int cmd_id;
    csv_t *csv;
    ptmlib_msg_type type;
} ptm_lib_msg_ctxt_t;

static csv_record_t *
_ptm_lib_encode_header(csv_t *csv,
		               csv_record_t *rec,
		               int msglen,
		               int version,
                       int type,
                       int cmd_id,
                       char *client_name)
{
    char msglen_buf[16], vers_buf[16], type_buf[16], cmdid_buf[16];
    char client_buf[32];
    csv_record_t *rec1;

    sprintf(msglen_buf, "%4u", msglen);
    sprintf(vers_buf, "%4u", version);
    sprintf(type_buf, "%4u", type);
    sprintf(cmdid_buf, "%4u", cmd_id);
    snprintf(client_buf, 17, "%16.16s", client_name);
    if (rec) {
        rec1 = csv_encode_record(csv, rec, 5, msglen_buf, vers_buf,
                type_buf, cmdid_buf, client_buf);
    } else {
        rec1 = csv_encode(csv, 5, msglen_buf, vers_buf,
                type_buf, cmdid_buf, client_buf);
    }
    return (rec1);
}

static int
_ptm_lib_decode_header (csv_t *csv,
                       int *msglen,
                       int *version,
                       int *type,
                       int *cmd_id,
                       char *client_name)
{
    char *hdr;
    csv_record_t *rec;
    csv_field_t *fld;
    int i, j;

    csv_decode(csv, NULL);
    rec = csv_record_iter(csv);
    if (rec == NULL) {
        DLOG("malformed CSV\n");
        return (-1);
    }
    hdr = csv_field_iter(rec, &fld);
    if (hdr == NULL) {
        DLOG("malformed CSV\n");
        return (-1);
    }
    *msglen = atoi(hdr);
    hdr = csv_field_iter_next(&fld);
    if (hdr == NULL) {
        DLOG("malformed CSV\n");
        return (-1);
    }
    *version = atoi(hdr);
    hdr = csv_field_iter_next(&fld);
    if (hdr == NULL) {
        DLOG("malformed CSV\n");
        return (-1);
    }
    *type = atoi(hdr);
    hdr = csv_field_iter_next(&fld);
    if (hdr == NULL) {
        DLOG("malformed CSV\n");
        return (-1);
    }
    *cmd_id = atoi(hdr);
    hdr = csv_field_iter_next(&fld);
    if (hdr == NULL) {
        DLOG("malformed CSV\n");
        return (-1);
    }
    /* remove leading spaces */
    for (i = j = 0; i < csv_field_len(fld); i++) {
        if (!isspace(hdr[i])) {
            client_name[j] = hdr[i];
            j++;
        }
    }
    client_name[j] = '\0';

    return (0);
}

int
ptm_lib_append_msg(ptm_lib_handle_t *hdl, void *ctxt,
                   const char *key, const char *val)
{
    ptm_lib_msg_ctxt_t *p_ctxt = ctxt;
    csv_t *csv;
    csv_record_t *mh_rec, *rec;

    if (!p_ctxt) {
        ERRLOG("%s: no context \n", __FUNCTION__);
        return -1;
    }

    csv = p_ctxt->csv;
    mh_rec = csv_record_iter(csv);
    rec = csv_record_iter_next(mh_rec);

    /* append to the hdr record */
    rec = csv_append_record(csv, rec, 1, key);
    if (!rec) {
        ERRLOG("%s: Could not append key \n", __FUNCTION__);
        return -1;
    }

    rec = csv_record_iter_next(rec);
    /* append to the data record */
    rec = csv_append_record(csv, rec, 1, val);
    if (!rec) {
        ERRLOG("%s: Could not append val \n", __FUNCTION__);
        return -1;
    }

    /* update the msg hdr */
    _ptm_lib_encode_header(csv, mh_rec,
                    (csvlen(csv) - PTMLIB_MSG_HDR_LEN),
                    PTMLIB_MSG_VERSION, p_ctxt->type,
                    p_ctxt->cmd_id, hdl->client_name);

    return 0;
}

int
ptm_lib_init_msg(ptm_lib_handle_t *hdl, int cmd_id, int type,
                 void *in_ctxt, void **out_ctxt)
{
    ptm_lib_msg_ctxt_t *p_ctxt;
    ptm_lib_msg_ctxt_t *p_in_ctxt = in_ctxt;
    csv_t *csv;
    csv_record_t *rec, *d_rec;

    /* Initialize csv for using discrete record buffers */
    csv = csv_init(NULL, NULL, PTMLIB_MSG_SZ);

    if (!csv) {
        ERRLOG("%s: Could not allocate csv \n", __FUNCTION__);
        return -1;
    }

    rec = _ptm_lib_encode_header(csv, NULL, 0,
                    PTMLIB_MSG_VERSION, type,
                    cmd_id, hdl->client_name);

    if (!rec) {
        ERRLOG("%s: Could not allocate record \n", __FUNCTION__);
        csv_clean(csv);
        csv_free(csv);
        return -1;
    }

    p_ctxt = calloc(1, sizeof(*p_ctxt));
    if (!p_ctxt) {
        ERRLOG("%s: Could not allocate context \n", __FUNCTION__);
        csv_clean(csv);
        csv_free(csv);
        return -1;
    }

    p_ctxt->csv = csv;
    p_ctxt->cmd_id = cmd_id;
    p_ctxt->type = type;

    *(ptm_lib_msg_ctxt_t **)out_ctxt = p_ctxt;

    /* caller supplied a context to initialize with? */
    if (p_in_ctxt) {
        /* insert the hdr rec */
        rec = csv_record_iter(p_in_ctxt->csv);
        csv_clone_record (p_in_ctxt->csv, rec, &d_rec);
        csv_insert_record (csv, d_rec);
        /* insert the data rec */
        rec = csv_record_iter_next(rec);
        csv_clone_record (p_in_ctxt->csv, rec, &d_rec);
        csv_insert_record (csv, d_rec);
    }
    return 0;
}

int
ptm_lib_complete_msg(ptm_lib_handle_t *hdl, void *ctxt,
                     char *buf, int *len)
{
    ptm_lib_msg_ctxt_t *p_ctxt = ctxt;
    csv_t *csv;
    csv_record_t *rec;

    if (!p_ctxt) {
        ERRLOG("%s: no context \n", __FUNCTION__);
        return -1;
    }

    csv = p_ctxt->csv;
    rec = csv_record_iter(csv);

    _ptm_lib_encode_header(csv, rec,
                    (csvlen(csv) - PTMLIB_MSG_HDR_LEN),
                    PTMLIB_MSG_VERSION, p_ctxt->type,
                    p_ctxt->cmd_id, hdl->client_name);

    /* parse csv contents into string */
    if (buf && len) {
        if (csv_serialize(csv, buf, *len)) {
            ERRLOG("%s: cannot serialize\n", __FUNCTION__);
            return -1;
        }
        *len = csvlen(csv);
    }

    csv_clean(csv);
    csv_free(csv);
    free(p_ctxt);

    return 0;
}

int
ptm_lib_find_key_in_msg(void *ctxt, const char *key, char *val)
{
    ptm_lib_msg_ctxt_t *p_ctxt = ctxt;
    csv_t *csv = p_ctxt->csv;
    csv_record_t *hrec, *drec;
    csv_field_t *hfld, *dfld;
    char *hstr, *dstr;

    /**
     * skip over ptm hdr if present
     * The next hdr is the keys (column name)
     * The next hdr is the data
     */
    if (csv_num_records(csv) > 2) {
        hrec = csv_record_iter(csv);
        hrec = csv_record_iter_next(hrec);
    } else {
        hrec = csv_record_iter(csv);
    }
    drec = csv_record_iter_next(hrec);
    val[0] = '\0';
    for(hstr = csv_field_iter(hrec, &hfld),
        dstr = csv_field_iter(drec, &dfld);
        (hstr && dstr);
        hstr = csv_field_iter_next(&hfld),
        dstr = csv_field_iter_next(&dfld)) {
        if (!strncmp(hstr, key, csv_field_len(hfld))) {
            snprintf(val, csv_field_len(dfld)+1, "%s", dstr);
            return 0;
        }
    }

    return -1;
}

static int
_ptm_lib_read_ptm_socket(int fd, char *buf, int len)
{
    int retries = 0, rc;
    int bytes_read = 0;

    while (bytes_read != len) {
        rc = recv(fd, (void *) (buf + bytes_read), (len - bytes_read),
                  MSG_DONTWAIT);
        if (rc <= 0) {
            if (errno && (errno != EAGAIN) && (errno != EWOULDBLOCK)) {
                ERRLOG("fatal recv error(%s), closing connection, rc %d\n",
                       strerror(errno), rc);
                return (rc);
            } else {
                if (retries++ < 2) {
                    usleep(10000);
                    continue;
                }
                DLOG("max retries - recv error(%d - %s) bytes read %d (%d)\n",
                     errno, strerror(errno), bytes_read, len);
                return (bytes_read);
            }
            break;
        } else {
            bytes_read += rc;
        }
    }

    return bytes_read;
}

int
ptm_lib_process_msg(ptm_lib_handle_t *hdl, int fd,
                    char *inbuf, int inlen, void *arg)
{
    int rc, len;
    char client_name[32];
    int cmd_id, type, ver, msglen;
    csv_t *csv;
    ptm_lib_msg_ctxt_t *p_ctxt;

    len = _ptm_lib_read_ptm_socket(fd, inbuf, PTMLIB_MSG_HDR_LEN);
    if (len <= 0)
        return (len);

    csv = csv_init(NULL, inbuf, PTMLIB_MSG_HDR_LEN);

    if (!csv) {
        DLOG("Cannot allocate csv for hdr\n");
        return (-1);
    }

    rc = _ptm_lib_decode_header(csv, &msglen, &ver, &type, &cmd_id, client_name);

    csv_clean(csv);
    csv_free(csv);

    if (rc < 0) {
        /* could not decode the CSV - maybe its legacy cmd?
         * get the entire cmd from the socket and see if we can process it
         */
        if (len == PTMLIB_MSG_HDR_LEN) {
            len += _ptm_lib_read_ptm_socket(fd, (inbuf+PTMLIB_MSG_HDR_LEN),
                                        inlen - PTMLIB_MSG_HDR_LEN);
            if (len <= 0)
                return (len);
        }

        inbuf[len] = '\0';
        /* we only support the get-status cmd */
        if (strcmp(inbuf, PTMLIB_CMD_GET_STATUS)) {
            DLOG("unsupported legacy cmd %s\n", inbuf);
            return (-1);
        }
        /* internally create a csv-style cmd */
        ptm_lib_init_msg(hdl, 0, PTMLIB_MSG_TYPE_CMD, NULL, (void *)&p_ctxt);
        if (!p_ctxt) {
            DLOG("couldnt allocate context\n");
            return (-1);
        }
        ptm_lib_append_msg(hdl, p_ctxt, "cmd", PTMLIB_CMD_GET_STATUS);

    } else {

        if (msglen > inlen) {
            DLOG("msglen [%d] > inlen [%d]\n", msglen, inlen);
            return -1;
        }

        /* read the rest of the msg */
        len = _ptm_lib_read_ptm_socket(fd, inbuf, msglen);
        if (len <= 0) {
            return (len);
        }

        inbuf[len] = '\0';

        csv = csv_init(NULL, NULL, PTMLIB_MSG_SZ);
        if (!csv) {
            ERRLOG("Cannot allocate csv for msg\n");
            return -1;
        }

        csv_decode(csv, inbuf);
        p_ctxt = calloc(1, sizeof(*p_ctxt));
        if (!p_ctxt) {
            ERRLOG("%s: Could not allocate context \n", __FUNCTION__);
            csv_clean(csv);
            csv_free(csv);
            return -1;
        }

        p_ctxt->csv = csv;
        p_ctxt->cmd_id = cmd_id;
        p_ctxt->type = type;
    }

    switch(p_ctxt->type) {
    case PTMLIB_MSG_TYPE_NOTIFICATION:
        if (hdl->notify_cb)
            hdl->notify_cb(arg, p_ctxt);
        break;
    case PTMLIB_MSG_TYPE_CMD:
        if (hdl->cmd_cb)
            hdl->cmd_cb(arg, p_ctxt);
        break;
    case PTMLIB_MSG_TYPE_RESPONSE:
        if (hdl->response_cb)
            hdl->response_cb(arg, p_ctxt);
        break;
    default:
        return -1;
    }

    csv_clean(p_ctxt->csv);
    csv_free(p_ctxt->csv);
    free(p_ctxt);

    return len;
}

ptm_lib_handle_t *
ptm_lib_register(char *client_name,
                 ptm_cmd_cb cmd_cb,
                 ptm_notify_cb notify_cb,
                 ptm_response_cb response_cb)
{
    ptm_lib_handle_t *hdl;

    hdl = calloc(1, sizeof(*hdl));

    if (hdl) {
        strncpy(hdl->client_name, client_name, PTMLIB_MAXNAMELEN - 1);
        hdl->cmd_cb = cmd_cb;
        hdl->notify_cb = notify_cb;
        hdl->response_cb = response_cb;
    }

    return hdl;
}

void
ptm_lib_deregister(ptm_lib_handle_t *hdl)
{
    if (hdl) {
        memset(hdl, 0x00, sizeof(*hdl));
        free(hdl);
    }
}