FreeCalypso > hg > freecalypso-tools
view rvinterf/asyncshell/tchcmd.c @ 465:003e48f8ebe1
rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel
I generally don't use NULL and use plain 0 instead, based on a "NULL
considered harmful" discussion on the classiccmp mailing list many aeons
ago (I couldn't find it, and I reason that it must have been 2005 or
earlier), but a recent complaint by a packager sent me searching, and I
found this:
https://ewontfix.com/11/
While I don't give a @#$% about "modern" systems and code-nazi tools,
I realized that passing a plain 0 as a pointer sentinel in execl is wrong
because it will break on systems where pointers are longer than the plain
int type. Again, I don't give a @#$% about the abomination of x86_64 and
the like, but if anyone ever manages to port my code to something like a
PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0
as a function argument where a pointer is expected most definitely won't
work: if the most natural stack slot and SP alignment unit is 16 bits,
fitting an int, with longs and pointers taking up two such slots, then
the call stack will be totally wrong with a plain 0 passed for a pointer.
Casting the 0 to (char *) ought to be the most kosher solution for the
most retro systems possible.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 11 Feb 2019 00:00:19 +0000 |
parents | d43d82cbfb85 |
children | 8171c5c0d804 |
line wrap: on
line source
/* * Commands for manipulating the experimental TCH rerouting feature * of FreeCalypso GSM firmware */ #include <sys/types.h> #include <stdio.h> #include <string.h> #include <strings.h> #include <stdlib.h> #include "pktmux.h" #include "limits.h" #include "tch_feature.h" #include "exitcodes.h" extern u_char rvi_msg[]; extern int rvi_msg_len; static int tch_rawdump_mode; send_tch_config_req(config) { u_char sendpkt[3]; sendpkt[0] = RVT_TCH_HEADER; sendpkt[1] = TCH_CONFIG_REQ; sendpkt[2] = config; /* send it! */ send_pkt_to_target(sendpkt, 3); return(0); } cmd_tchdl_common(argc, argv) char **argv; { int config; if (!strcmp(argv[0], "enable") || !strcmp(argv[0], "on") || !strcmp(argv[0], "1")) config = 1; else if (!strcmp(argv[0], "disable") || !strcmp(argv[0], "off") || !strcmp(argv[0], "0")) config = 0; else { printf("error: boolean argument required\n"); return(ERROR_USAGE); } return send_tch_config_req(config); } void cmd_tchdl_interactive(argstr) char *argstr; { char *argv[2]; int argc, rc; rc = parse_interactive_command_into_argv(argstr, argv, 1, 1, &argc); if (rc < 0) return; tch_rx_control(1); cmd_tchdl_common(argc, argv); } cmd_tchdl_oneshot(argc, argv) char **argv; { return cmd_tchdl_common(argc - 1, argv + 1); } static void tch_rawdump() { char buf[MAX_PKT_FROM_TARGET*3+5], *dp; u_char *cp, *endp; cp = rvi_msg + 2; endp = rvi_msg + rvi_msg_len; strcpy(buf, "TCH:"); dp = buf + 4; while (cp < endp) { sprintf(dp, " %02X", *cp++); dp += 3; } *dp = '\0'; async_msg_output(buf); } void tch_packet_rx() { char buf[128]; if (tch_rawdump_mode) { tch_rawdump(); return; } if (rvi_msg_len < 3) { inv: async_msg_output("Error: invalid TCH packet received"); return; } switch (rvi_msg[2]) { case TCH_CONFIG_CONF: if (rvi_msg_len != 4) goto inv; if (rvi_msg[3] & 0xFE) goto inv; sprintf(buf, "TCH_CONFIG_CONF: DL forwarding is %s", rvi_msg[3] ? "enabled" : "disabled"); async_msg_output(buf); return; case TCH_ULBITS_CONF: if (rvi_msg_len != 3) goto inv; tch_ulbits_conf(); return; case TCH_DLBITS_IND: if (rvi_msg_len != 43) goto inv; tch_dlbits_handler(); return; default: goto inv; } } static void cmd_tch_dumpraw(argc, argv) char **argv; { if (argc < 2) { printf("error: too few arguments\n"); return; } if (!strcmp(argv[1], "enable") || !strcmp(argv[1], "on") || !strcmp(argv[1], "1")) tch_rawdump_mode = 1; else if (!strcmp(argv[1], "disable") || !strcmp(argv[1], "off") || !strcmp(argv[1], "0")) tch_rawdump_mode = 0; else printf("error: boolean argument required\n"); } static void cmd_tch_status(argc, argv) char **argv; { if (argc > 1) { printf("error: too many arguments\n"); return; } show_tch_record_status(); show_tch_play_status(); printf("TCH raw dump mode is %s\n", tch_rawdump_mode ? "enabled" : "disabled"); } void cmd_tch_dispatch(argstr) char *argstr; { char *argv[3]; int argc, rc; rc = parse_interactive_command_into_argv(argstr, argv, 1, 2, &argc); if (rc < 0) return; if (!strcmp(argv[0], "dump-raw")) { cmd_tch_dumpraw(argc, argv); return; } if (!strcmp(argv[0], "play")) { cmd_tch_play(argc, argv); return; } if (!strcmp(argv[0], "record")) { cmd_tch_record(argc, argv); return; } if (!strcmp(argv[0], "status")) { cmd_tch_status(argc, argv); return; } printf("error: invalid tch subcommand\n"); }