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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:18:56 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:18:56 +0000 |
commit | b7c15c31519dc44c1f691e0466badd556ffe9423 (patch) | |
tree | f944572f288bab482a615e09af627d9a2b6727d8 /src/global/off_cvt.c | |
parent | Initial commit. (diff) | |
download | postfix-b7c15c31519dc44c1f691e0466badd556ffe9423.tar.xz postfix-b7c15c31519dc44c1f691e0466badd556ffe9423.zip |
Adding upstream version 3.7.10.upstream/3.7.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/global/off_cvt.c')
-rw-r--r-- | src/global/off_cvt.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/src/global/off_cvt.c b/src/global/off_cvt.c new file mode 100644 index 0000000..3efb0b7 --- /dev/null +++ b/src/global/off_cvt.c @@ -0,0 +1,158 @@ +/*++ +/* NAME +/* off_cvt 3 +/* SUMMARY +/* off_t conversions +/* SYNOPSIS +/* #include <off_cvt.h> +/* +/* off_t off_cvt_string(string) +/* const char *string; +/* +/* VSTRING *off_cvt_number(result, offset) +/* VSTRING *result; +/* off_t offset; +/* DESCRIPTION +/* This module provides conversions between \fIoff_t\fR and string. +/* +/* off_cvt_string() converts a string, containing a non-negative +/* offset, to numerical form. The result is -1 in case of problems. +/* +/* off_cvt_number() converts a non-negative offset to string form. +/* +/* Arguments: +/* .IP string +/* String with non-negative number to be converted to off_t. +/* .IP result +/* Buffer for storage of the result of conversion to string. +/* .IP offset +/* Non-negative off_t value to be converted to string. +/* DIAGNOSTICS +/* Panic: negative offset +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/* +/* Wietse Venema +/* Google, Inc. +/* 111 8th Avenue +/* New York, NY 10011, USA +/*--*/ + +/* System library. */ + +#include <sys_defs.h> +#include <sys/types.h> +#include <ctype.h> + +/* Utility library. */ + +#include <msg.h> +#include <vstring.h> + +/* Global library. */ + +#include "off_cvt.h" + +/* Application-specific. */ + +#define STR vstring_str +#define END vstring_end +#define SWAP(type, a, b) { type temp; temp = a; a = b; b = temp; } + +/* off_cvt_string - string to number */ + +off_t off_cvt_string(const char *str) +{ + int ch; + off_t result; + off_t digit_value; + + /* + * Detect overflow before it happens. Code that attempts to detect + * overflow after-the-fact makes assumptions about undefined behavior. + * Compilers may invalidate such assumptions. + */ + for (result = 0; (ch = *(unsigned char *) str) != 0; str++) { + if (!ISDIGIT(ch)) + return (-1); + digit_value = ch - '0'; + if (result > OFF_T_MAX / 10 + || (result *= 10) > OFF_T_MAX - digit_value) + return (-1); + result += digit_value; + } + return (result); +} + +/* off_cvt_number - number to string */ + +VSTRING *off_cvt_number(VSTRING *buf, off_t offset) +{ + static char digs[] = "0123456789"; + char *start; + char *last; + int i; + + /* + * Sanity checks + */ + if (offset < 0) + msg_panic("off_cvt_number: negative offset -%s", + STR(off_cvt_number(buf, -offset))); + + /* + * First accumulate the result, backwards. + */ + VSTRING_RESET(buf); + while (offset != 0) { + VSTRING_ADDCH(buf, digs[offset % 10]); + offset /= 10; + } + VSTRING_TERMINATE(buf); + + /* + * Then, reverse the result. + */ + start = STR(buf); + last = END(buf) - 1; + for (i = 0; i < VSTRING_LEN(buf) / 2; i++) + SWAP(int, start[i], last[-i]); + return (buf); +} + +#ifdef TEST + + /* + * Proof-of-concept test program. Read a number from stdin, convert to + * off_t, back to string, and print the result. + */ +#include <vstream.h> +#include <vstring_vstream.h> + +int main(int unused_argc, char **unused_argv) +{ + VSTRING *buf = vstring_alloc(100); + off_t offset; + + while (vstring_fgets_nonl(buf, VSTREAM_IN)) { + if (STR(buf)[0] == '#' || STR(buf)[0] == 0) + continue; + if ((offset = off_cvt_string(STR(buf))) < 0) { + msg_warn("bad input %s", STR(buf)); + } else { + vstream_printf("%s\n", STR(off_cvt_number(buf, offset))); + } + vstream_fflush(VSTREAM_OUT); + } + vstring_free(buf); + return (0); +} + +#endif |