FreeCalypso > hg > freecalypso-tools
view rvinterf/libprint/back_esc.c @ 965:2969032bdfac
fcup-smsend[mult]: fix buglet in K&R C NULL pointer passing
The only 100% safe way to pass a NULL pointer as a function argument
in K&R C is to cast 0 to a pointer type; failing to do so may cause
mysterious bugs (invalid stack frames or garbage in argument registers)
on 64-bit machines. This issue has already been fixed in most of
FC host tools, but I just found some missed spots: passing of NULL UDH
to PDU encoding functions in fcup-smsend[mult] in the case of single
(not concatenated) SMS.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Fri, 01 Sep 2023 07:33:51 +0000 |
parents | 6a0aa8d36d06 |
children |
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/* * The function implemented in this module prints a potentially-dirty string * into a buffer with C-style backslash escapes, including doubling of any * already-present backslashes. The output buffer must be sized for up to * 4x expansion, plus the terminating NUL. */ #include <sys/types.h> #include <ctype.h> #include <stdio.h> void safe_print_trace(src, srclen, dest) u_char *src; char *dest; { int i, c; char *dp; dp = dest; for (i = 0; i < srclen; i++) { c = src[i]; switch (c) { case '\\': *dp++ = '\\'; *dp++ = '\\'; continue; case '\r': *dp++ = '\\'; *dp++ = 'r'; continue; case '\n': *dp++ = '\\'; *dp++ = 'n'; continue; } if (c >= ' ' && c <= '~') *dp++ = c; else if (c <= 7 && (i+1 == srclen || !isdigit(src[i+1]))) { sprintf(dp, "\\%d", c); dp += 2; } else { sprintf(dp, "\\x%02X", c); dp += 4; } } *dp = '\0'; }