Okay, yes, there are issues with the code to The Protocol Stack From Hell™ [1]. There's the vowel impaired names—oh, sorry, the vwl_imprd_nms, the usual ignoring return codes and tons of global variables—sorry, glblvrbls littering the code. And there's stuff like:
>
```
foo_t *p = NULL;
/* lots of code not touching p at all */
if (p) {
/* lots of code that will never be executed because */
/* p is always, *always* NULL at this point */
} else {
/* this code will always *always* be executed */
/* p is never touched otherwise */
}
/* p is still never used */
```
Yes. At one point p was probaby used, then a code change sometime during the Clinton Administration [2] (late first term most likely) removed the need for p but later code still checked it, so in order to keep the code from crashing (during the last year of the Clinton Administration, most likely) the “easiest fix that would work with minimal code changes because we want to avoid a five day regression test” is to just NULL out the variable where declared and call it a day.
Odder yet is the code that generates a string, checks to see if the generated string ends with two newline characters and then adds one or two newline characters if required (and yes, it checks for the first newline character, then the second) and further down in the code, it checks to see if the line has two newline characters and carefully removes them, one at a time.
Yes. The code adds two characters, only to remove them later on.
Again, I can see the requirements late during the Reagan Administration [3] bumping up against the requirements during the early Bush 43 Adminstration [4] and again, the easiest way to handle this is a local change that distrubs as little code as possible.
Although, there is one bit that does smack of rabid howler monkeys on crack taking a pass at the code, which I briefly mention in passing [5]. It's basically the Poster Child™ for why certain C programmers should be taken out back behind the shed and disembowled with a grapefruit spoon [6].
Back then, I was tasked with modifying some code to log the Protocol Stack From Hell™ errors via syslog(), and all I had to work with was a C source file:
>
```
/* tons o' broilerplate text whereby we pledge our first born to feed the
* lawyers of The Protocol Stack From Hell™ */
void Stpd_Init_Fnctn(void)
{
MYSTERIOUS_ENTRY_CODE_WE_CANT_TOUCH();
/* modifications here */
MYSTERIOUS_EXIT_CODE_WE_CANT_TOUCH();
}
void Stpd_Lrm_Fnctn(lrm_t *ptr,int wat)
{
MYSTERIOUS_ENTRY_CODE_WE_CANT_TOUCH();
/* modifications here */
MYSTERIOUS_EXIT_CODE_WE_CANT_TOUCH();
}
/* Muahahahahahahahahahahahaha! */
/* [S/X thunder ] */
```
(No, seriously, each function starts and ends with MYSTERIOUS_something_CODE_WE_CANT_TOUCH()) and an object file, which the C code is linked against to produce the final program.
Okay, nothing that out of the ordinary. Only we weren't getting the proper error messages from the lrm_t … thingy … we were given. Some back and forth with The Protocol Stack From Hell™ Technical Support® and we had the final solution, and if you can read C code, prepared to be horrified:
>
```
void Stpd_Lrm_Fnctn(lrm_t *prt,int wat)
{
char *msg;
MYSTERIOUS_ENTRY_CODE_WE_CANT_TOUCH();
msg = (char *)prt + sizeof(lrm_t);
syslog(LOG_WTF,"error: %s",msg);
MYSTERIOUS_EXIT_CODE_WE_CANT_TOUCH();
}
```
For those not fluent in C, let me translate: “you will receive a block of memory called prt, which has a particular layout we laughingly call lrm_t. Ignore the data there, but instead, what you actually want lies just past the block of memory you received, into an area that Standard C calls “undefined behavior.” Abandon all hope ye who program here. And have a nice day.”
Then, I was horrified. Now, I get to see the code from “the other side” and “horrified” does not describe my reaction. “Running away, screaming in sheer madness of having peered deep into the Abyss” would be a bit closer, but still misses the mark. It goes something like this.
>
```
typedef struct {
/* data data data */ /* [1] */
} lrm_t;
typedef struct {
/* a mass of data */
arbitrary_size_t reserved[6]; /* [2] */
} msg_t;
void rnd_fnct(int wat)
{
/* don't worry, these are big enough */
char inbffr[256],tmpbffr[256],msgbffr[256]; /* [3] */
msg_t *msg;
lrm_t lrm,*plrm;
/* a bunch of code to receive an SS7 message and determine that the */
/* contents need to be logged, as it indicates an error */
msg = (msg_t *)inbffr;
frmt_rnd_msg(msgbffr,msg); /* we know how big the resulting buffer is */
/* okay, now for the real horror show */
memcpy(&lrm,msg->reserved,sizeof(lrm_t)); /* [4] */
/* No! Don't go into the basement! */
memcpy(tmpbffr,&lrm,sizeof(lrm_t)); /* [5] */
/* The call originated from inside the house! */
strcpy(&tmpbffr[sizeof(lrm_t)],msgbffr); /* [6] */
/* Aieeeeeeeeeeeeeeeeeeeeeeeee! stabbity stab stab */
Stpd_Lrm_Fnctn((lrm_t *)tmpbffr,wat); /* [7] */
}
```
And now for the play-by-play commentary on this horror show:
Rabid howler monkeys on crack.
I'm serious.
There aren't enough facepalms to do this code justice.
[2] http://en.wikipedia.org/wiki/Presidency_of_Bill_Clinton
[3] http://en.wikipedia.org/wiki/Presidency_of_Ronald_Reagan
[4] http://en.wikipedia.org/wiki/Presidency_of_George_W._Bush