cosmopolitan/libc/dns/getservbyport.c
Gautham 0ea2907730
Add getservbyname and getservbyport (#204)
For every call of getservbyname/getservbyport the lookup of
/etc/services is done by opening the file and parsing each line
one-by-one. This is slow, but the implementation is simple.

This change also adds fixes for the gethostbyname function.
2021-07-04 16:31:42 -07:00

63 lines
3.4 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ This is free and unencumbered software released into the public domain. │
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│ Anyone is free to copy, modify, publish, use, compile, sell, or │
│ distribute this software, either in source code form or as a compiled │
│ binary, for any purpose, commercial or non-commercial, and by any │
│ means. │
│ │
│ In jurisdictions that recognize copyright laws, the author or authors │
│ of this software dedicate any and all copyright interest in the │
│ software to the public domain. We make this dedication for the benefit │
│ of the public at large and to the detriment of our heirs and │
│ successors. We intend this dedication to be an overt act of │
│ relinquishment in perpetuity of all present and future rights to this │
│ software under copyright law. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF │
│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. │
│ IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR │
│ OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, │
│ ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR │
│ OTHER DEALINGS IN THE SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/dns/ent.h"
#include "libc/dns/servicestxt.h"
struct servent *getservbyport(int port, const char *proto) {
static struct servent *ptr1, se1;
char name[DNS_NAME_MAX];
char *localproto = proto;
if (!ptr1) {
se1.s_name = NULL;
se1.s_aliases = (char **)malloc(sizeof(char *) * 1);
if (!se1.s_aliases) return NULL;
se1.s_aliases[0] = NULL;
se1.s_port = 0;
se1.s_proto = NULL;
ptr1 = &se1;
}
if (LookupServicesByPort(port, &localproto, name, sizeof(name)) == -1) {
// localproto got alloc'd during the lookup?
if (!proto && localproto != proto) free(localproto);
return NULL;
}
ptr1->s_port = port;
if (ptr1->s_name) free(ptr1->s_name);
ptr1->s_name = strdup(name);
if (ptr1->s_proto) free(ptr1->s_proto);
ptr1->s_proto = strdup(localproto);
if (!proto && localproto != proto) free(localproto);
return ptr1;
}