/*

 * Copyright (C) 2024-2025 OpenSIPS Solutions

 *

 * This file is part of opensips, a free SIP server.

 *

 * opensips 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 of the License, or

 * (at your option) any later version

 *

 * opensips 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 this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include "pvar.h"

#include "sdp_ops.h"

#include "ut.h"

#include "parser/sdp/sdp.h"

enum sdp_pv_name {

  SDP_PV_NAME_P1_NAME,

  SDP_PV_NAME_P2_STREAM,

  SDP_PV_NAME_P3_LINE,

  SDP_PV_NAME_P4_TOKEN,

};

#define SDP_PV_IDX_INSERT  1

#define SDP_PV_IDX_AINSERT 2

void free_sdp_ops_lines(struct sdp_body_part_ops *ops);

struct sdp_body_part_ops *mk_sdp_ops(void)

{

  struct sdp_body_part_ops *ops;

  ops = pkg_malloc(sizeof *ops);

  if (!ops) {

    LM_ERR("oom\n");

    return NULL;

  }

  memset(ops, 0, sizeof *ops);

  return ops;

}

/* fetch the value of a static/dynamic index */

static inline int IDX(struct sip_msg *msg, struct sdp_pv_idx *idx)

{

  pv_value_t val;

  if (!idx->is_pv_idx)

    return idx->idx;

  if (pv_get_spec_value(msg, &idx->idx_pv, &val) != 0) {

    LM_ERR("failed to get idx spec value\n");

    return -1;

  }

  if (!(val.flags & PV_VAL_INT)) {

    LM_ERR("SDP idx spec contains non-INT value ('%.*s')\n",

            val.rs.len, val.rs.s);

    return -1;

  }

  return val.ri;

}

/* returns a string representation of the index (useful for debugging) */

static inline char *IDX_STR(struct sdp_pv_idx *idx)

{

#define idx_buf_cnt 4

  static char buf[idx_buf_cnt][20];

  static int buf_idx;

  char *p;

  p = buf[buf_idx];

  buf_idx = (buf_idx+1) % idx_buf_cnt;

  if (!idx->is_pv_idx)

    sprintf(p, "%d", idx->idx);

  else

    sprintf(p, "pv type %d", idx->idx_pv.type);

  return p;

}

static inline int sdp_detect_line_sep(str *sdp, char *sep, int *sep_len)

{

  char *p, *lim = sdp->s + sdp->len;

  /* detect separator using first line

   *   (avoid checking last line -- some UAs omit the LF) */

  for (p = sdp->s; p < lim && *p != '\n' && *p != '\r'; p++) {};

  if (p == lim)

    return 0;

  sep[0] = *p;

  if (*p == '\r' && (p+1)<lim && *(p+1) == '\n') {

    sep[1] = '\n';

    *sep_len = 2;

  } else {

    *sep_len = 1;

  }

  return 1;

}

int pv_set_sdp(struct sip_msg *msg, pv_param_t *param,

      int op, pv_value_t *val)

{

  struct sdp_body_part_ops *ops;

  int null_before = 0;

  if (!msg || !param) {

    LM_ERR("bad parameters\n");

    return -1;

  }

  if (!msg->sdp_ops) {

    ops = msg->sdp_ops = mk_sdp_ops();

    if (!ops) {

      LM_ERR("oom\n");

      return -1;

    }

  } else {

    ops = msg->sdp_ops;

  }

  if (!val) {

    LM_ERR("sdp-set: NULL\n");

    ops->flags |= SDP_OPS_FL_NULL;

    ops->flags &= ~SDP_OPS_FL_DIRTY;

    if (msg->body) {

      free_sip_body(msg->body);

      msg->body = NULL;

    }

    free_sdp_ops_lines(ops);

    pkg_free(ops->rebuilt_sdp.s);

    ops->rebuilt_sdp.s = NULL;

  } else {

    LM_ERR("sdp-set: non-NULL!\n");

    if (!(val->flags & PV_VAL_STR) || val->rs.len <= 0) {

      LM_ERR("non-empty str value required to set SDP body\n");

      goto error;

    }

    if (pkg_str_sync(&ops->sdp, &val->rs) != 0) {

      LM_ERR("oom\n");

      return -1;

    }

    if (ops->flags & SDP_OPS_FL_NULL) {

      null_before = 1;

      ops->flags &= ~SDP_OPS_FL_NULL;

    }

    if (msg->body) {

      free_sip_body(msg->body);

      msg->body = NULL;

    }

    if (parse_sip_body(msg) != 0) {

      LM_ERR("bad body provided (%.*s ...), refusing to set in SIP msg\n",

              val->rs.len>=40 ? 40:val->rs.len, val->rs.s);

      pkg_free(ops->sdp.s);

      ops->sdp = STR_NULL;

      if (null_before)

        ops->flags |= SDP_OPS_FL_NULL;

      return -1;

    }

    if (!parse_sdp(msg)) {

      LM_ERR("bad SDP provided (%.*s ...), refusing to set in SIP msg\n",

              val->rs.len>=40 ? 40:val->rs.len, val->rs.s);

      free_sip_body(msg->body);

      msg->body = NULL;

      pkg_free(ops->sdp.s);

      ops->sdp = STR_NULL;

      if (null_before)

        ops->flags |= SDP_OPS_FL_NULL;

      return -1;

    }

    if (!sdp_detect_line_sep(&ops->sdp, ops->sep, &ops->sep_len)) {

      LM_ERR("failed to detect SDP separator, first 50B: '%.*s'\n",

              ops->sdp.len >= 50 ? 50:ops->sdp.len, ops->sdp.s);

      free_sip_body(msg->body);

      msg->body = NULL;

      pkg_free(ops->sdp.s);

      ops->sdp = STR_NULL;

      memset(ops->sep, 0, 2);

      if (null_before)

        ops->flags |= SDP_OPS_FL_NULL;

      return -1;

    }

    if (ops->sdp.s[ops->sdp.len-1] > '\r')

      ops->flags |= SDP_OPS_FL_NO_LLF;

    free_sdp_ops_lines(ops);

    if (ops->rebuilt_sdp.s) {

      pkg_free(ops->rebuilt_sdp.s);

      ops->rebuilt_sdp = STR_NULL;

    }

    LM_DBG("separator: %d %d (%d)\n", ops->sdp.s[ops->sdp.len-2],

            ops->sdp.s[ops->sdp.len-1], ops->sep_len);

  }

  return 0;

error:

  return -1;

}

static char *parse_sdp_pv_index(char *in, int len, struct sdp_pv_idx *idx)

{

  char *lim = in + len, *end;

  long val = -1;

  if (len <= 0)

    return NULL;

  if (in[0] == PV_MARKER) {

    str input = {.s = in, .len = len};

    if (!(end = pv_parse_spec(&input, &idx->idx_pv))) {

      LM_ERR("failed to parse spec idx!  input: '%.*s'\n", len, in);

      return NULL;

    }

    idx->is_pv_idx = 1;

    goto parse_bracket;

  }

  val = strtol(in, &end, 10);

  if (errno == ERANGE) {

    LM_ERR("failed to parse index: value too big\n");

    return NULL;

  }

  if (val == -1) {

    LM_ERR("failed to parse index, given input: ...[%.*s\n", len, in);

    return NULL;

  }

parse_bracket:

  while (end < lim && is_ws(*end))

    end++;

  if (end == lim || *end != ']') {

    LM_ERR("failed to parse index, given input: ...[%.*s\n", len, in);

    return NULL;

  }

  while (end+1 < lim && is_ws(*(end+1)))

    end++;

  idx->idx = val;

  return end;

}

int pv_parse_sdp_name(pv_spec_p sp, const str *_in)

{

  // TODO -- add support for custom SDP holders

  str in = *_in, tok;

  int escape = 0, i;

  enum sdp_pv_name nm = SDP_PV_NAME_P3_LINE;

  struct sdp_pv_param *param;

  char *p, *lim = in.s + in.len;

  if (!sp)

    return -1;

  LM_DBG("parse sdp name: '%.*s'\n", in.len, in.s);

  trim(&in);

  if (!in.s || in.len == 0)

    goto done;

  if (in.s[0] == PV_MARKER) {

    LM_ERR("no support for dynamic names in $sdp.line\n");

    return -1;

  } else if (in.s[0] == '@') {

    // TODO: impl custom SDP holders (perhaps using a map)

    return -1;

  }

  param = pkg_malloc(sizeof *param);

  if (!param) {

    LM_ERR("oom\n");

    return -1;

  }

  memset(param, 0, sizeof *param);

  tok.s = in.s;

  for (i = 0; i < in.len; i++) {

    struct sdp_pv_idx idx = {0};

    if (escape && (in.s[i] == '\\' || in.s[i] == '/')) {

      memmove(&in.s[i-1], &in.s[i], in.len - i);

      in.len--;

      i--;

      escape = 0;

      continue;

    }

    if (in.s[i] == '\\') {

      escape = 1;

      continue;

    }

    escape = 0;

    if (in.s[i] == '[') {

      p = parse_sdp_pv_index(in.s + i + 1, in.len - i - 1, &idx);

      if (!p) {

        LM_ERR("error while parsing index in $sdp name: '%.*s'\n", in.len, in.s);

        return -1;

      }

      if (p < lim && *p != '/') {

        LM_ERR("error after index part in $sdp name: '%.*s'\n", in.len, in.s);

        return -1;

      }

      i += p - (in.s + i);

      continue;

    }

    if (in.s[i] == '/' && nm <= SDP_PV_NAME_P4_TOKEN) {

      tok.len = i - (tok.s - in.s);

      // save tok

      switch (nm) {

      case SDP_PV_NAME_P1_NAME:

      case SDP_PV_NAME_P2_STREAM:

      case SDP_PV_NAME_P3_LINE:

        param->match_line.prefix = tok;

        tok.s = in.s + i + 1;

        break;

      case SDP_PV_NAME_P4_TOKEN:

        param->match_token.prefix = tok;

        break;

      }

      nm++;

      continue;

    }

  }

  LM_DBG("parse sdp name: '%.*s'\n", in.len, in.s);

  sp->pvp.pvn.type = PV_NAME_PVAR;

  sp->pvp.pvn.u.dname = param;

done:

  return 0;

}

int pv_parse_sdp_line_index(pv_spec_p sp, const str *in)

{

  #define SDP_INSERT_IDX  "insert"

  #define SDP_AINSERT_IDX "insertAfter"

  if (!in || !in->s || !sp)

    return -1;

  if (str_casematch(in, &str_init(SDP_INSERT_IDX))) {

    sp->pvp.pvi.type = SDP_PV_IDX_INSERT;

    return 0;

  }

  if (str_casematch(in, &str_init(SDP_AINSERT_IDX))) {

    sp->pvp.pvi.type = SDP_PV_IDX_AINSERT;

    return 0;

  }

  LM_ERR("unsupported SDP variable index: '%.*s'\n", in->len, in->s);

  return -1;

}

int sdp_ops_parse_lines(struct sdp_body_part_ops *ops, str *body)

{

  char *p, *lim = body->s + body->len, _sep[2], sep, *start;

  int sep_len = 1, i = 0;

  if (!sdp_detect_line_sep(body, _sep, &sep_len)) {

    LM_ERR("failed to detect SDP separator, first 50B: '%.*s'\n",

            body->len >= 50 ? 50:body->len, body->s);

    return -1;

  }

  sep = _sep[0];

  start = body->s;

  for (p = start; p < lim; p++) {

    if (*p != sep || (sep_len == 2 && p < (lim-1) && *(p+1) != '\n'))

      continue;

    if (i >= SDP_MAX_LINES) {

      LM_ERR("SDP body exceeds maximum line count (%d)\n",

          SDP_MAX_LINES);

      return -1;

    }

    /* lines are stored *without* the ending separator */

    ops->lines[i].line.s = start;

    ops->lines[i].line.len = p - start;

    ops->lines[i++].newbuf = 0;

    start = p + sep_len;

  }

  /* edge-case: the very last SDP line does not include a separator... */

  if (start < lim) {

    if (i >= SDP_MAX_LINES) {

      LM_ERR("SDP body exceeds maximum line count (%d)\n",

          SDP_MAX_LINES);

      return -1;

    }

    ops->lines[i].line.s = start;

    ops->lines[i].line.len = p - start;

    ops->lines[i++].newbuf = 0;

    ops->flags |= SDP_OPS_FL_NO_LLF;

  }

  LM_DBG("parsed %d SDP lines in total\n", i);

  ops->lines_sz = i;

  memcpy(ops->sep, _sep, sep_len);

  ops->sep_len = sep_len;

  return 0;

}

#define first_part_by_mime( _part_start, _part_end, _mime) \

  do {\

    _part_end = _part_start;\

    while( (_part_end) && \

    !(is_body_part_received(_part_end) && ((_mime)==0 || \

    (_mime)==(_part_end)->mime )) ) { \

      _part_end = (_part_end)->next; \

    } \

  }while(0)

/* @until_line: non-inclusive (i.e. must be next-after last valid line) */

int _sdp_ops_find_line(struct sdp_body_part_ops *ops, int idx,

            str *prefix, str *token, int from_line, int until_line)

{

  int i;

  if ((from_line+idx) > until_line || (from_line+idx) >= SDP_MAX_LINES ||

          (token->s && (from_line+idx) == until_line)) {

    LM_DBG("index out of bounds (trying to fetch line %d, prefix: %.*s/%d"

                ", have %d lines)\n",

            idx, prefix->len, prefix->s, prefix->len, until_line);

    return -1;

  }

  if (prefix->len == 0)

    return from_line + idx;

  for (i = from_line; i < until_line; i++) {

    /* have prefix and doesn't match current line => skip it */

    if (prefix->len > ops->lines[i].line.len

            || strncasecmp(prefix->s, ops->lines[i].line.s, prefix->len))

      continue;

    /* have index, but still too high => skip line */

    if (idx > 0) {

      idx--;

      continue;

    }

    /* line found */

    return i;

  }

  return -1;

}

/* Note: MAY return the very "next last" line idx, to enable INSERT ops */

static inline int sdp_ops_find_line(struct sip_msg *msg, struct sdp_body_part_ops *ops, int idx,

        int by_session, struct sdp_chunk_match *by_stream, str *prefix, str *token)

{

  int i, j, have_stream = 0, stream_idx;

  struct sdp_ops_line *lines;

  if (!by_stream) {

    if (!by_session)

      return _sdp_ops_find_line(ops, idx, prefix, token, 0, ops->lines_sz);

    /* the SDP session ends at the first m= line */

    lines = ops->lines;

    for (i = 0; i < ops->lines_sz; i++) {

      if (lines[i].line.len < 2 || strncasecmp("m=", lines[i].line.s, 2))

        continue;

      break;

    }

    idx = _sdp_ops_find_line(ops, idx, prefix, token, 0, i);

    return (idx > i || (idx == i && by_session == 1)) ? -1 : idx;

  }

  lines = ops->lines;

  stream_idx = IDX(msg, &by_stream->idx);

  for (i = 0; i < ops->lines_sz; i++) {

    if (lines[i].line.len < 2 || strncasecmp("m=", lines[i].line.s, 2))

      continue;

    if (by_stream->prefix.len > (lines[i].line.len-2)

            || strncasecmp(by_stream->prefix.s, lines[i].line.s+2, by_stream->prefix.len))

      continue;

    if (stream_idx-- > 0)

      continue;

    have_stream = 1;

    break;

  }

  if (!have_stream) {

    LM_DBG("failed to locate a stream by prefix: '%.*s', index: %d\n",

            by_stream->prefix.len, by_stream->prefix.s, IDX(msg, &by_stream->idx));

    return -1;

  }

  for (j = i+1; j < ops->lines_sz; j++) {

    if (lines[j].line.len < 2 || strncasecmp("m=", lines[j].line.s, 2))

      continue;

    break;

  }

  LM_DBG("located stream by prefix: '%.*s', idx: %d; interval: [%d, %d)\n",

            by_stream->prefix.len, by_stream->prefix.s, IDX(msg, &by_stream->idx), i, j);

  return _sdp_ops_find_line(ops, idx, prefix, token, i, j);

}

int pv_get_sdp_line(struct sip_msg *msg, pv_param_t *param, pv_value_t *res)

{

  struct sdp_pv_param *pvp = (struct sdp_pv_param *)param->pvn.u.dname;

  struct sdp_body_part_ops *ops;

  struct sip_msg_body *sbody;

  struct body_part *body_part;

  str body, line = STR_NULL, pfx, token = STR_NULL;

  char *p, *lim, *start;

  int idx;

  if (!msg || !res)

    return pv_get_null(msg, param, res);

  if (msg->body_lumps) {

    /* TODO: rebuild SDP body, clear the body lumps; assert lines_sz == 0 */

  }

  if (!have_sdp_ops(msg) || msg->sdp_ops->lines_sz == 0) {

    if (parse_sip_body(msg)<0 || !(sbody=msg->body)) {

      LM_ERR("current SIP message has no SDP body!\n");

      return pv_get_null(msg, param, res);

    }

    first_part_by_mime( &sbody->first, body_part, (TYPE_APPLICATION<<16)+SUBTYPE_SDP );

    if (!body_part) {

      LM_ERR("current SIP message has a body, but no SDP part!\n");

      return pv_get_null(msg, param, res);

    }

    ops = msg->sdp_ops;

    /* first time working with SDP ops => allocate DS */

    if (!ops && !(ops = msg->sdp_ops = mk_sdp_ops())) {

      LM_ERR("oom\n");

      return pv_get_null(msg, param, res);

    }

    body = body_part->body;

    if (ops->lines_sz == 0 && sdp_ops_parse_lines(ops, &body) != 0) {

      LM_ERR("oom\n");

      return pv_get_null(msg, param, res);

    }

  } else {

    ops = msg->sdp_ops;

  }

  idx = sdp_ops_find_line(msg, ops, IDX(msg, &pvp->match_line.idx), 0, NULL,

          &pvp->match_line.prefix, &pvp->match_token.prefix);

  if (idx < 0 || idx >= ops->lines_sz)    // out of bounds

    return pv_get_null(msg, param, res);

  line = ops->lines[idx].line;

  if (!pvp->match_token.prefix.s)

    return pv_get_strval(msg, param, res, &line);

  idx = IDX(msg, &pvp->match_token.idx);

  pfx = pvp->match_token.prefix;

  start = line.s;

  lim = line.s + line.len;

  while (start < lim && is_ws(*start))

    start++;

  for (p = start; p <= lim; p++) {

    if (p < lim && !is_ws(*p))

      continue;

    /* have prefix and doesn't match current token => skip token */

    if (pfx.len && (pfx.len > (p-start) || strncasecmp(pfx.s, start, pfx.len))) {

      while (p < lim && is_ws(*p))

        p++;

      start = p;

      continue;

    }

    if (idx > 0) {

      idx--;

      start = p;

      while (start < lim && is_ws(*start))

        start++;

      continue;

    }

    token.s = start;

    token.len = p - start;

    break;

  }

  if (!token.s)

    return pv_get_null(msg, param, res);

  return pv_get_strval(msg, param, res, &token);

}

int pv_set_sdp_line(struct sip_msg *msg, pv_param_t *param,

      int op, pv_value_t *val)

{

  struct sdp_pv_param *pvp = (struct sdp_pv_param *)param->pvn.u.dname;

  struct sip_msg_body *sbody;

  struct sdp_body_part_ops *ops;

  struct body_part *body_part;

  str body, dup_line, src_line;

  int idx, insert = 0;

  if (!msg)

    return -1;

  if (val && !(val->flags & PV_VAL_STR)) {

    LM_ERR("refusing to set SDP line to non-string value (val flags: %d)\n",

                val->flags);

    return -1;

  }

  if (msg->body_lumps) {

    /* TODO: rebuild SDP body, clear the body lumps; assert lines_sz == 0 */

  }

  if (!have_sdp_ops(msg) || msg->sdp_ops->lines_sz == 0) {

    if (parse_sip_body(msg)<0 || !(sbody=msg->body)) {

      LM_ERR("current SIP message has no SDP body!\n");

      return -1;

    }

    first_part_by_mime( &sbody->first, body_part, (TYPE_APPLICATION<<16)+SUBTYPE_SDP );

    if (!body_part) {

      LM_ERR("current SIP message has a body, but no SDP part!\n");

      return -1;

    }

    ops = msg->sdp_ops;

    /* first time working with SDP ops => allocate DS */

    if (!ops && !(ops = msg->sdp_ops = mk_sdp_ops())) {

      LM_ERR("oom\n");

      return -1;

    }

    body = body_part->body;

    if (ops->lines_sz == 0 && sdp_ops_parse_lines(ops, &body) != 0) {

      LM_ERR("oom\n");

      return -1;

    }

  } else {

    ops = msg->sdp_ops;

  }

  idx = IDX(msg, &pvp->match_line.idx);

  switch (param->pvi.type) {

  case SDP_PV_IDX_INSERT:

    insert = 1;

    break;

  case SDP_PV_IDX_AINSERT:

    insert = 1;

    idx++; /* convert it to "INSERT" operation */

    break;

  default:

    break;

  }

  idx = sdp_ops_find_line(msg, ops, idx, 0, NULL, &pvp->match_line.prefix,

                               &pvp->match_token.prefix);

  if (idx < 0) {

    LM_ERR("failed to locate SDP line for writing for line %d, match_token: "

            "'%.*s'\n", IDX(msg, &pvp->match_line.idx),

            pvp->match_line.prefix.len, pvp->match_line.prefix.s);

    return -1;

  }

  if (pvp->match_token.prefix.s)

    goto handle_token_edit;

  /* delete line operation -> ignore the index */

  if (!val) {

    if (idx == ops->lines_sz) {

      LM_ERR("index out of bounds (trying to delete SDP line %d, have %d lines)\n",

              idx, ops->lines_sz);

      return -1;

    }

    if (ops->lines[idx].newbuf)

      pkg_free(ops->lines[idx].line.s);

    memmove(&ops->lines[idx], &ops->lines[idx+1], (ops->lines_sz-idx-1)*sizeof *ops->lines);

    ops->lines[idx].have_gap = 1;

    ops->lines_sz--;

    goto out_success;

  }

  /* trim any trailing \n, \r or \r\n from the input */

  src_line = val->rs;

  if (src_line.len > 0 && (src_line.s[src_line.len-1] == '\n' || src_line.s[src_line.len-1] == '\r')) {

    src_line.len--;

    if (src_line.len > 0 && src_line.s[src_line.len] == '\n' && src_line.s[src_line.len-1] == '\r')

      src_line.len--;

  }

  if (pkg_str_dup(&dup_line, &src_line) != 0) {

    LM_ERR("oom\n");

    return -1;

  }

  if (insert) {

    /* insert line operation */

    memmove(&ops->lines[idx+1], &ops->lines[idx], (ops->lines_sz-idx)*sizeof *ops->lines);

    ops->lines_sz++;

  } else {

    /* edit line operation -> ignore the PV index */

    if (ops->lines[idx].newbuf)

      pkg_free(ops->lines[idx].line.s);

  }

  ops->lines[idx].line = dup_line;

  ops->lines[idx].newbuf = 1;

  goto out_success;

handle_token_edit:

out_success:

  ops->flags |= SDP_OPS_FL_DIRTY;

  return 0;

}

int pv_parse_sdp_line_name(pv_spec_p sp, const str *_in)

{

  str in = *_in, tok;

  int escape = 0, i, midx = 0;

  struct sdp_pv_param *param;

  struct sdp_chunk_match *matches[3];

  char *p;

  if (!sp)

    return -1;

  if (!in.s || in.len == 0)

    goto done;

  if (in.s[0] == PV_MARKER) {

    LM_ERR("no support for dynamic names in $sdp.line\n");

    return -1;

  } else if (in.s[0] == '@') {

    // TODO: impl custom SDP holders (perhaps using a map)

    return -1;

  }

  param = pkg_malloc(sizeof *param);

  if (!param) {

    LM_ERR("oom\n");

    return -1;

  }

  memset(param, 0, sizeof *param);

  matches[0] = &param->match_line;

  matches[1] = &param->match_token;

  matches[2] = NULL;

  tok.s = in.s;

  for (i = 0; i < in.len; i++) {

    if (!matches[midx])

      break;

    if (escape && (in.s[i] == '\\' || in.s[i] == '/')) {

      memmove(&in.s[i-1], &in.s[i], in.len - i);

      in.len--;

      i--;

      escape = 0;

      continue;

    }

    if (in.s[i] == '\\') {

      escape = 1;

      continue;

    }

    escape = 0;

    if (in.s[i] == '[' || in.s[i] == '/') {

      tok.len = i - (tok.s - in.s);

      trim_leading(&tok);

      if (in.s[i] == '[') {

        p = parse_sdp_pv_index(in.s + i + 1, in.len - i - 1, &matches[midx]->idx);

        if (!p) {

          LM_ERR("error while parsing index in $sdp name: '%.*s'\n", in.len, in.s);

          return -1;

        }

        p = q_memchr(p, '/', in.s + in.len - p);

        if (!p) {

          matches[midx++]->prefix = tok;

          break;

        }