From 5b8d37094a38aff1b2669056a4011a42450fd9c5 Mon Sep 17 00:00:00 2001 From: Michael Smith Date: Sat, 2 Jul 2022 21:51:50 +0100 Subject: Add alias management plus input filtering skeleton Some of the alias stuff was kind of stolen from earlier figuring-out Bill did. More Bill code is also on the way. :^) --- src/alias.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 src/alias.c (limited to 'src/alias.c') diff --git a/src/alias.c b/src/alias.c new file mode 100644 index 0000000..7db5907 --- /dev/null +++ b/src/alias.c @@ -0,0 +1,112 @@ +/* + * Copyright © 2022 Michael Smith + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH + * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR + * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ + +#include +#include + +#include "alias.h" +#include "con_.h" +#include "dbg.h" +#include "errmsg.h" +#include "extmalloc.h" +#include "mem.h" +#include "x86.h" + +struct alias **_alias_head; + +void alias_rm(const char *name) { + for (struct alias **p = _alias_head; *p; p = &(*p)->next) { + if (!strcmp((*p)->name, name)) { + struct alias *next = (*p)->next; + extfree((*p)->value); extfree(*p); + *p = next; + return; + } + } +} + +DEF_CCMD_HERE(sst_alias_remove, "Remove a command alias", 0) { + if (cmd->argc != 2) { + con_warn("usage: sst_alias_remove name"); + return; + } + if (strlen(cmd->argv[1]) > 31) { + con_warn("invalid alias name (too long)"); + return; + } + alias_rm(cmd->argv[1]); +} + +void alias_nuke(void) { + for (struct alias *p = alias_head; p;) { + struct alias *next = p->next; + extfree(p->value); extfree(p); + p = next; + } + alias_head = 0; +} + +DEF_CCMD_HERE(sst_alias_clear, "Remove all command aliases", 0) { + if (cmd->argc != 1) { + con_warn("usage: sst_alias_clear"); + return; + } + alias_nuke(); +} + +// XXX: same as in demorec, might want some abstraction for this +#define NEXT_INSN(p, tgt) do { \ + int _len = x86_len(p); \ + if (_len == -1) { \ + errmsg_errorx("unknown or invalid instruction looking for %s", tgt); \ + return false; \ + } \ + (p) += _len; \ +} while (0) + +static bool find_alias_head(con_cmdcb alias_cb) { +#ifdef _WIN32 + for (uchar *p = (uchar *)alias_cb; p - (uchar *)alias_cb < 64;) { + // alias command with no args calls ConMsg() then loads the head pointer + // that asm looks like: call ; mov , dword ptr [x] + // (we don't care about the exact registers) + if (p[0] == X86_MISCMW && (p[1] & 0xF0) == 0xD0 && + p[2] == X86_MOVRMW && (p[3] & 0xC7) == 0x05) { + _alias_head = mem_loadptr(p + 4); + return true; + } + NEXT_INSN(p, "load of alias list"); + } +#else +#warning TODO(linux): check whether linux is equivalent! +#endif + return false; +} + +bool alias_init(void) { + struct con_cmd *cmd_alias = con_findcmd("alias"); + if (!cmd_alias) { + errmsg_warnx("couldn't find \"alias\" command"); + return false; + } + if (!find_alias_head(con_getcmdcb(cmd_alias))) { + errmsg_warnx("couldn't find alias list"); + return false; + }; + return true; +} + +// vi: sw=4 ts=4 noet tw=80 cc=80 -- cgit v1.2.3