FreeCalypso > hg > themwi-system-sw
view libsip/primary_parse.c @ 124:7e04d28fae8b
sip-in: default use-100rel to no
BulkVS servers act badly when we send a reliable 180 Ringing response
to an incoming call, even though they advertise 100rel support in
the Supported header in the INVITE packet, and we probably won't be
implementing 100rel for outbound because doing per-the-spec PRACK
as a UAC is just too burdensome. Therefore, we need to consider
100rel extension as not-really-supported in themwi-system-sw.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Sat, 01 Oct 2022 15:54:50 -0800 |
parents | f1cf80c7e243 |
children |
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/* * In this module we are going to implement the first stage of * parsing for incoming SIP UDP packets, using struct sip_pkt_rx * defined in parse.h. */ #include <ctype.h> #include <string.h> #include <strings.h> #include <stdlib.h> #include "parse.h" static find_crlf(ptr, msg_end, endp, nextp) char *ptr, *msg_end, **endp, **nextp; { for (;;) { if (ptr >= msg_end) return(0); switch (*ptr) { case '\0': return(0); case '\n': *endp = ptr; *nextp = ptr + 1; return(1); case '\r': *endp = ptr; ptr++; if (ptr >= msg_end) return(0); if (*ptr != '\n') return(0); *nextp = ptr + 1; return(1); } ptr++; } } static try_status_line(msg) struct sip_pkt_rx *msg; { if (strncasecmp(msg->pkt_buffer, "SIP/2.0 ", 8)) return(0); if (!isdigit(msg->pkt_buffer[8])) return(0); if (!isdigit(msg->pkt_buffer[9])) return(0); if (!isdigit(msg->pkt_buffer[10])) return(0); if (msg->pkt_buffer[11] != ' ') return(0); msg->status_code = atoi(msg->pkt_buffer + 8); msg->status_str = msg->pkt_buffer + 8; return(1); } static try_request_line(msg) struct sip_pkt_rx *msg; { char *cp; cp = msg->pkt_buffer; if (!isupper(*cp)) return(0); while (isalnum(*cp)) cp++; if (*cp != ' ') return(0); msg->req_method = msg->pkt_buffer; *cp++ = '\0'; msg->req_uri = cp; while (*cp && !isspace(*cp)) cp++; if (*cp != ' ') return(0); *cp++ = '\0'; if (strcasecmp(cp, "SIP/2.0")) return(0); else return(1); } static void trim_trailing_spaces(sp) char *sp; { char *ep; ep = index(sp, '\0'); while (ep > sp && isspace(ep[-1])) ep--; *ep = '\0'; } parse_incoming_sip_msg(msg) struct sip_pkt_rx *msg; { char *msg_end = msg->pkt_buffer + msg->pkt_length; char *cp, *endp, *nextp, *sp; unsigned hdr_cnt; int rc; /* begin by isolating the Request-Line or Status-Line */ rc = find_crlf(msg->pkt_buffer, msg_end, &endp, &nextp); if (!rc) return(-1); *endp = '\0'; if (try_status_line(msg)) msg->parse_msgtype = SIP_MSG_TYPE_RESP; else if (try_request_line(msg)) msg->parse_msgtype = SIP_MSG_TYPE_REQ; else return(-1); /* now preparse header fields */ cp = nextp; for (hdr_cnt = 0; ; ) { rc = find_crlf(cp, msg_end, &endp, &nextp); if (!rc) return(-1); if (endp == cp) /* final CRLF? */ break; if (!isalpha(*cp)) return(-1); if (hdr_cnt >= MAX_HEADER_FIELDS) return(-2); msg->hdr_fields[hdr_cnt].field_name = cp; while (cp < endp && (isalnum(*cp) || *cp == '-')) cp++; if (cp >= endp) return(-1); if (*cp == ':') *cp++ = '\0'; else if (isspace(*cp)) { *cp++ = '\0'; while (cp < endp && isspace(*cp)) cp++; if (cp >= endp) return(-1); if (*cp++ != ':') return(-1); } else return(-1); sp = cp; cp = nextp; while (cp < msg_end && (*cp == ' ' || *cp == '\t')) { rc = find_crlf(cp, msg_end, &endp, &nextp); if (!rc) return(-1); cp = nextp; } *endp = '\0'; while (isspace(*sp)) sp++; trim_trailing_spaces(sp); msg->hdr_fields[hdr_cnt++].field_value = sp; } msg->num_hdr_fields = hdr_cnt; msg->msg_body = nextp; msg->msg_body_len = msg_end - nextp; return(0); }