FreeCalypso > hg > freecalypso-sw
view rvinterf/libg23/fmtdispatch.c @ 812:b522307de6f2
aci: psa_ss?.c done
author | Space Falcon <falcon@ivan.Harhan.ORG> |
---|---|
date | Sun, 05 Apr 2015 07:58:27 +0000 |
parents | 42c91c51ca7f |
children | ca65f5adf1af |
line wrap: on
line source
/* * This libg23 module exports the format_g23_packet() function, which * validates the packet, then dispatches it to format_g23_trace(), * format_g23_sysprim() or format_g23_psprim() as appropriate, or * prints it in raw hex if malformed. */ #include <sys/types.h> #include <stdio.h> #include <string.h> #include <strings.h> static int basic_checks(rxpkt, rxpkt_len) u_char *rxpkt; { int i, c; if (rxpkt_len < 17) return(0); /* check version bits in the header byte */ if ((rxpkt[1] & 0xC0) != 0x80) return(0); /* check the length */ c = rxpkt[2] | rxpkt[3] << 8; if (c + 4 != rxpkt_len) return(0); /* ensure that the "from" and "to" are printable ASCII */ for (i = 8; i < 16; i++) { c = rxpkt[i]; if (c < ' ' || c > '~') return(0); } /* basic checks pass */ return(1); } static int psprim_extra_checks(rxpkt, rxpkt_len) u_char *rxpkt; { int i, c; if (rxpkt_len < 24) return(0); /* "original rcvr" field needs to be printable ASCII */ for (i = 16; i < 20; i++) { c = rxpkt[i]; if (c < ' ' || c > '~') return(0); } /* checks pass */ return(1); } static void print_malformed(rxpkt, rxpkt_len, outbuf) u_char *rxpkt; char *outbuf; { int i; char *dp; dp = outbuf; strcpy(dp, "GPF UNK:"); dp += 8; for (i = 1; i < rxpkt_len; i++) { sprintf(dp, " %02X", rxpkt[i]); dp += 3; } *dp = '\0'; } void format_g23_packet(rxpkt, rxpkt_len, outbuf) u_char *rxpkt; char *outbuf; { if (!basic_checks(rxpkt, rxpkt_len)) { print_malformed(rxpkt, rxpkt_len, outbuf); return; } /* dispatch by type */ switch (rxpkt[1] & 0x30) { case 0x10: /* PS primitive */ if (psprim_extra_checks(rxpkt, rxpkt_len)) format_g23_psprim(rxpkt, rxpkt_len, outbuf); else print_malformed(rxpkt, rxpkt_len, outbuf); return; case 0x20: /* trace */ format_g23_trace(rxpkt, rxpkt_len, outbuf); return; case 0x30: /* system primitive */ format_g23_sysprim(rxpkt, rxpkt_len, outbuf); return; default: print_malformed(rxpkt, rxpkt_len, outbuf); } }