mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-03-02 23:18:44 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Add getservbyname and getservbyport (#204)

Browse source 
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.
This commit is contained in:
Gautham 2021-07-05 05:01:42 +05:30 • committed by GitHub
parent cfbd2afc19
commit 0ea2907730
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
8 changed files with 412 additions and 25 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

13
libc/dns/ent.h
View file

@ -16,12 +16,25 @@ struct hostent {
};
#define h_addr h_addr_list[0]
struct servent {
char *s_name; /* official service name */
char **s_aliases; /* alias list */
int s_port; /* port number (in network byte order) */
char *s_proto; /* protocol to use */
};
struct hostent *gethostent(void);
struct hostent *gethostbyname(const char *);
struct hostent *gethostbyaddr(const void *, socklen_t, int);
void sethostent(int);
void endhostent(void);
struct servent *getservent(void);
struct servent *getservbyname(const char *, const char *);
struct servent *getservbyport(int, const char *);
void setservent(int);
void endservent(void);
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_DNS_ENT_H_ */

23
libc/dns/gethostbyaddr.c
View file

@ -31,23 +31,24 @@
struct hostent *gethostbyaddr(const void *s_addr, socklen_t len, int type) {
static struct hostent *ptr1, he1;
static char h_name[DNS_NAME_MAX+1];
static char* h_aliases[1];
static char* h_addr_list[2];
static char h_addr_list0[4];
struct sockaddr_in addr;
char name[DNS_NAME_MAX + 1];
if (!ptr1) {
he1.h_name = NULL;
he1.h_name = h_name;
he1.h_aliases = (char **)malloc(sizeof(char *) * 1);
if (!he1.h_aliases) return NULL;
he1.h_aliases = h_aliases;
he1.h_aliases[0] = NULL;
he1.h_addrtype = AF_INET;
he1.h_length = 4;
he1.h_addr_list = (char **)malloc(sizeof(char *) * 2);
if (!he1.h_addr_list) return NULL;
he1.h_addr_list = h_addr_list;
he1.h_addr_list[0] = (char *)malloc(sizeof(uint32_t));
if (!he1.h_addr_list[0]) return NULL;
he1.h_addr_list[0] = h_addr_list0;
he1.h_addr_list[1] = NULL;
ptr1 = &he1;
@ -58,12 +59,10 @@ struct hostent *gethostbyaddr(const void *s_addr, socklen_t len, int type) {
addr.sin_port = 0;
addr.sin_addr.s_addr = *(uint32_t *)(s_addr);
if (getnameinfo((struct sockaddr *)&addr, sizeof(addr), name, sizeof(name),
NULL, 0, 0))
if (getnameinfo((struct sockaddr *)&addr, sizeof(addr), ptr1->h_name,
DNS_NAME_MAX, NULL, 0, 0))
return NULL;
if (ptr1->h_name) free(ptr1->h_name);
ptr1->h_name = strdup(name);
*((uint32_t *)ptr1->h_addr_list[0]) = (addr.sin_addr.s_addr);
return ptr1;

28
libc/dns/gethostbyname.c
View file

@ -27,26 +27,28 @@
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/dns/ent.h"
#include "libc/mem/mem.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/af.h"
struct hostent *gethostbyname(const char *name) {
static struct hostent *ptr0, he0;
static char h_name[DNS_NAME_MAX + 1];
static char *h_aliases[1];
static char *h_addr_list[2];
static char h_addr_list0[4];
struct addrinfo *result = NULL;
if (!ptr0) {
he0.h_name = NULL;
he0.h_name = h_name;
he0.h_aliases = (char **)malloc(sizeof(char *) * 1);
if (!he0.h_aliases) return NULL;
he0.h_aliases = h_aliases;
he0.h_aliases[0] = NULL;
he0.h_addrtype = AF_INET;
he0.h_length = 4;
he0.h_addr_list = (char **)malloc(sizeof(char *) * 2);
if (!he0.h_addr_list) return NULL;
he0.h_addr_list = h_addr_list;
he0.h_addr_list[0] = (char *)malloc(sizeof(uint32_t));
if (!he0.h_addr_list[0]) return NULL;
he0.h_addr_list[0] = h_addr_list0;
he0.h_addr_list[1] = NULL;
ptr0 = &he0;
@ -54,12 +56,12 @@ struct hostent *gethostbyname(const char *name) {
if (getaddrinfo(name, NULL, NULL, &result) || result == NULL) return NULL;
if (ptr0->h_name) free(ptr0->h_name);
if (result->ai_canonname) {
ptr0->h_name = strdup(result->ai_canonname);
} else {
ptr0->h_name = strdup(name);
}
/* if getaddrinfo is successful, result->ai_canonname is non-NULL,
* (see newaddrinfo) but the string can still be empty */
if (result->ai_canonname[0])
memccpy(ptr0->h_name, result->ai_canonname, '\0', DNS_NAME_MAX);
else
memccpy(ptr0->h_name, name, '\0', DNS_NAME_MAX);
*((uint32_t *)ptr0->h_addr_list[0]) = (result->ai_addr4->sin_addr.s_addr);
/* TODO: if result has ai_next, fit multiple entries for h_addr_list */

65
libc/dns/getservbyname.c Normal file
View file

@ -0,0 +1,65 @@
/*-*- 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. │
│ │
│ 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. │
│ │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/dns/ent.h"
#include "libc/dns/servicestxt.h"
#include "libc/mem/mem.h"
struct servent *getservbyname(const char *name, const char *proto) {
static struct servent *ptr0, se0;
char *localproto = proto;
int p;
if (!ptr0) {
se0.s_name = NULL;
se0.s_aliases = (char **)malloc(sizeof(char *) * 1);
if (!se0.s_aliases) return NULL;
se0.s_aliases[0] = NULL;
se0.s_port = 0;
se0.s_proto = NULL;
ptr0 = &se0;
}
p = LookupServicesByName(name, &localproto);
if (p == -1) {
// localproto got alloc'd during the lookup?
if (!proto && localproto != proto) free(localproto);
return NULL;
}
ptr0->s_port = p;
if (ptr0->s_name) free(ptr0->s_name);
ptr0->s_name = strdup(name);
if (ptr0->s_proto) free(ptr0->s_proto);
ptr0->s_proto = strdup(localproto);
if (!proto && localproto != proto) free(localproto);
return ptr0;
}

63
libc/dns/getservbyport.c Normal file
View file

@ -0,0 +1,63 @@
/*-*- 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. │
│ │
│ 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. │
│ │
╚─────────────────────────────────────────────────────────────────────────────*/
#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;
}

38
libc/dns/servent.c Normal file
View file

@ -0,0 +1,38 @@
/*-*- 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. │
│ │
│ 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. │
│ │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/dns/ent.h"
struct servent *getservent(void) {
return NULL;
}
void setservent(int stayopen) {
}
void endservent(void) {
}

190
libc/dns/servicestxt.c Normal file
View file

@ -0,0 +1,190 @@
/*-*- 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. │
│ │
│ 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. │
│ │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/dns/servicestxt.h"
#include "libc/bits/safemacros.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/fmt/conv.h"
#include "libc/fmt/fmt.h"
#include "libc/macros.internal.h"
#include "libc/mem/mem.h"
#include "libc/nt/systeminfo.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
static textwindows noinline char *GetNtServicesTxtPath(char *pathbuf,
uint32_t size) {
const char *const kWinHostsPath = "\\drivers\\etc\\services";
uint32_t len = GetSystemDirectoryA(&pathbuf[0], size);
if (len && len + strlen(kWinHostsPath) + 1 < size) {
if (pathbuf[len] == '\\') pathbuf[len--] = '\0';
memcpy(&pathbuf[len], kWinHostsPath, strlen(kWinHostsPath) + 1);
return &pathbuf[0];
} else {
return NULL;
}
}
/**
* Opens and searches /etc/services to find name for a given port.
*
* format of /etc/services is like this:
*
* # comment
* # NAME PORT/PROTOCOL ALIASES
*
* ftp 21/tcp
* fsp 21/udp fspd
* ssh 22/tcp
*
* @param servport is the port number (in network byte order)
* @param servproto is a pointer to a string (*servproto can be NULL)
* @param buf is a buffer to store the resulting name
* @param bufsize is the size of buf
* @returns 0 on success, -1 on error
*
* @note aliases are not read from the file.
*/
int LookupServicesByPort(const int servport, char **servproto, char *buf,
size_t bufsize) {
FILE *f;
char *line;
char pathbuf[PATH_MAX];
const char *path;
size_t linesize;
int count, found;
char *name, *port, *proto, *comment, *tok;
path = "/etc/services";
if (IsWindows()) {
path = firstnonnull(GetNtServicesTxtPath(pathbuf, ARRAYLEN(pathbuf)), path);
}
if (bufsize == 0 || !(f = fopen(path, "r"))) {
return -1;
}
line = NULL;
linesize = 0;
count = 0;
found = 0;
while (found == 0 && (getline(&line, &linesize, f)) != -1) {
if ((comment = strchr(line, '#'))) *comment = '\0';
name = strtok_r(line, " \t\r\n\v", &tok);
port = strtok_r(NULL, "/ \t\r\n\v", &tok);
if (name && port && servport == htons(atoi(port))) {
if (!(proto = strtok_r(NULL, " \t\r\n\v", &tok)))
continue;
else if (!servproto[0]) {
servproto[0] = strdup(proto);
strncpy(buf, name, bufsize);
found = 1;
} else if (strcmp(proto, servproto[0]) == 0) {
strncpy(buf, name, bufsize);
found = 1;
}
}
count++;
}
free(line);
if (ferror(f)) {
errno = ferror(f);
return -1;
}
fclose(f);
if (!found) return -1;
return 0;
}
/**
* Opens and searches /etc/services to find port for a given name.
*
* @param servname is a NULL-terminated string
* @param servproto is a pointer to a string (*servproto can be NULL)
* @returns -1 on error, or
* positive port number (in network byte order)
*
* @note aliases are not read from the file.
* @see LookupServicesByPort
*/
int LookupServicesByName(const char *servname, char **servproto) {
FILE *f;
char *line;
char pathbuf[PATH_MAX];
const char *path;
size_t linesize;
int count, found, result;
char *name, *port, *proto, *comment, *tok;
path = "/etc/services";
if (IsWindows()) {
path = firstnonnull(GetNtServicesTxtPath(pathbuf, ARRAYLEN(pathbuf)), path);
}
if (!(f = fopen(path, "r"))) {
return -1;
}
line = NULL;
linesize = 0;
count = 0;
found = 0;
result = -1;
while (found == 0 && (getline(&line, &linesize, f)) != -1) {
if ((comment = strchr(line, '#'))) *comment = '\0';
name = strtok_r(line, " \t\r\n\v", &tok);
port = strtok_r(NULL, "/ \t\r\n\v", &tok);
if (name && port && strcmp(name, servname) == 0) {
if (!(proto = strtok_r(NULL, " \t\r\n\v", &tok)))
continue;
else if (!servproto[0]) {
servproto[0] = strdup(proto);
result = htons(atoi(port));
found = 1;
} else if (strcmp(proto, servproto[0]) == 0) {
result = htons(atoi(port));
found = 1;
}
}
count++;
}
free(line);
if (ferror(f)) {
errno = ferror(f);
return -1;
}
fclose(f);
if (!found) return -1;
return result;
}

17
libc/dns/servicestxt.h Normal file
View file

@ -0,0 +1,17 @@
#ifndef COSMOPOLITAN_LIBC_DNS_SERVICESTXT_H_
#define COSMOPOLITAN_LIBC_DNS_SERVICESTXT_H_
#include "libc/sock/sock.h"
#include "libc/stdio/stdio.h"
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
int LookupServicesByPort(const int, char **, char *, size_t)
paramsnonnull((2, 3));
int LookupServicesByName(const char *, char **) paramsnonnull((1, 2));
/* TODO: implement like struct HostsTxt? */
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_DNS_SERVICESTXT_H_ */