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Improve getservbyname and getservbyport (#207)

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- support aliases in /etc/services
- use case insensitive comparisons
- add tests
This commit is contained in:
Gautham 2021-07-06 00:55:26 +05:30 • committed by GitHub
parent 58fb2fb3d3
commit c0bec24fa2
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GPG key ID: 4AEE18F83AFDEB23
7 changed files with 202 additions and 58 deletions
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13
libc/dns/getservbyname.c
View file

@ -31,21 +31,19 @@
struct servent *getservbyname(const char *name, const char *proto) {
static struct servent *ptr0, se0;
static char s_name[DNS_NAME_MAX + 1];
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_name = s_name;
if (!(se0.s_aliases = calloc(1, sizeof(char *)))) return NULL;
se0.s_port = 0;
se0.s_proto = NULL;
ptr0 = &se0;
}
p = LookupServicesByName(name, &localproto);
p = LookupServicesByName(name, &localproto, ptr0->s_name, DNS_NAME_MAX, NULL);
if (p == -1) {
// localproto got alloc'd during the lookup?
if (!proto && localproto != proto) free(localproto);
@ -53,9 +51,6 @@ struct servent *getservbyname(const char *name, const char *proto) {
}
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);

15
libc/dns/getservbyport.c
View file

@ -30,30 +30,25 @@
struct servent *getservbyport(int port, const char *proto) {
static struct servent *ptr1, se1;
char name[DNS_NAME_MAX];
static char s_name[DNS_NAME_MAX + 1];
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_name = s_name;
if (!(se1.s_aliases = calloc(1, sizeof(char *)))) return NULL;
se1.s_port = 0;
se1.s_proto = NULL;
ptr1 = &se1;
}
if (LookupServicesByPort(port, &localproto, name, sizeof(name)) == -1) {
if (LookupServicesByPort(port, &localproto, ptr1->s_name, DNS_NAME_MAX,
NULL) == -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);

67
libc/dns/servicestxt.c
View file

@ -65,51 +65,54 @@ static textwindows noinline char *GetNtServicesTxtPath(char *pathbuf,
*
* @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 buf is a buffer to store the official name of the service
* @param bufsize is the size of buf
* @param filepath is the location of the services file
* (if NULL, uses /etc/services)
* @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) {
size_t bufsize, const char *filepath) {
FILE *f;
char *line;
char pathbuf[PATH_MAX];
const char *path;
size_t linesize;
int count, found;
int found;
char *name, *port, *proto, *comment, *tok;
if (!(path = filepath)) {
path = "/etc/services";
if (IsWindows()) {
path = firstnonnull(GetNtServicesTxtPath(pathbuf, ARRAYLEN(pathbuf)), path);
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]) {
proto = strtok_r(NULL, " \t\r\n\v", &tok);
if (name && port && proto && servport == htons(atoi(port))) {
if (!servproto[0]) {
servproto[0] = strdup(proto);
strncpy(buf, name, bufsize);
found = 1;
} else if (strcmp(proto, servproto[0]) == 0) {
} else if (strcasecmp(proto, servproto[0]) == 0) {
strncpy(buf, name, bufsize);
found = 1;
}
}
count++;
}
free(line);
@ -129,32 +132,39 @@ int LookupServicesByPort(const int servport, char **servproto, char *buf,
*
* @param servname is a NULL-terminated string
* @param servproto is a pointer to a string (*servproto can be NULL)
* @param buf is a buffer to store the official name of the service
* @param bufsize is the size of buf
* @param filepath is the location of services file
* (if NULL, uses /etc/services)
* @returns -1 on error, or
* positive port number (in network byte order)
*
* @note aliases are not read from the file.
* @note aliases are read from file for comparison, but not returned.
* @see LookupServicesByPort
*/
int LookupServicesByName(const char *servname, char **servproto) {
int LookupServicesByName(const char *servname, char **servproto, char *buf,
size_t bufsize, const char *filepath) {
FILE *f;
char *line;
char pathbuf[PATH_MAX];
const char *path;
size_t linesize;
int count, found, result;
char *name, *port, *proto, *comment, *tok;
int found, result;
char *name, *port, *proto, *alias, *comment, *tok;
if (!(path = filepath)) {
path = "/etc/services";
if (IsWindows()) {
path = firstnonnull(GetNtServicesTxtPath(pathbuf, ARRAYLEN(pathbuf)), path);
path =
firstnonnull(GetNtServicesTxtPath(pathbuf, ARRAYLEN(pathbuf)), path);
}
if (!(f = fopen(path, "r"))) {
}
if (bufsize == 0 || !(f = fopen(path, "r"))) {
return -1;
}
line = NULL;
linesize = 0;
count = 0;
found = 0;
result = -1;
@ -162,19 +172,26 @@ int LookupServicesByName(const char *servname, char **servproto) {
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]) {
proto = strtok_r(NULL, " \t\r\n\v", &tok);
if (name && port && proto) {
alias = name;
while (alias && strcasecmp(alias, servname) != 0)
alias = strtok_r(NULL, " \t\r\n\v", &tok);
if (alias) /* alias matched with servname */
{
if (!servproto[0]) {
servproto[0] = strdup(proto);
result = htons(atoi(port));
strncpy(buf, name, bufsize);
found = 1;
} else if (strcmp(proto, servproto[0]) == 0) {
} else if (strcasecmp(proto, servproto[0]) == 0) {
result = htons(atoi(port));
strncpy(buf, name, bufsize);
found = 1;
}
}
count++;
}
}
free(line);

5
libc/dns/servicestxt.h
View file

@ -6,9 +6,10 @@
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
int LookupServicesByPort(const int, char **, char *, size_t)
int LookupServicesByPort(const int, char **, char *, size_t, const char *)
paramsnonnull((2, 3));
int LookupServicesByName(const char *, char **) paramsnonnull((1, 2));
int LookupServicesByName(const char *, char **, char *, size_t, const char *)
paramsnonnull((1, 2, 3));
/* TODO: implement like struct HostsTxt? */

135
test/libc/dns/servicestxt_test.c Normal file
View file

@ -0,0 +1,135 @@
/*-*- 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/dns/dns.h"
#include "libc/dns/ent.h"
#include "libc/calls/calls.h"
#include "libc/testlib/testlib.h"
char testlib_enable_tmp_setup_teardown;
void SetUp() {
int fd;
const char* sample = "\
# skip comment string\n\
chargen 19/tcp ttytst source\n\
chargen 19/udp ttytst source\n\
ssh 22/tcp # SSH Remote Login Protocol";
ASSERT_NE(-1, (fd = creat("services", 0755)));
ASSERT_NE(-1, write(fd, sample, strlen(sample)));
ASSERT_NE(-1, close(fd));
}
TEST(LookupServicesByPort, GetNameWhenPortCorrect) {
char name[16]; /* sample has only names of length 3 */
char proto1[] = "tcp";
char proto2[] = "udp";
char* localproto[1];
localproto[0] = NULL;
ASSERT_EQ(
-1, /* non existent port */
LookupServicesByPort(965, localproto, name, sizeof(name), "services"));
ASSERT_EQ(NULL, localproto[0]);
ASSERT_EQ(
-1, /* port not in network byte order */
LookupServicesByPort(22, localproto, name, sizeof(name), "services"));
ASSERT_EQ(NULL, localproto[0]);
localproto[0] = proto2;
ASSERT_EQ(-1, /* port ok but wrong protocol */
LookupServicesByPort(htons(22), localproto, name, sizeof(name),
"services"));
ASSERT_EQ(localproto[0], proto2);
localproto[0] = proto1;
ASSERT_EQ(0, LookupServicesByPort(htons(22), localproto, name, sizeof(name),
"services"));
ASSERT_STREQ(name, "ssh");
ASSERT_EQ(localproto[0], proto1);
localproto[0] = proto2;
ASSERT_EQ(0, LookupServicesByPort(htons(19), localproto, name,
sizeof(name), "services"));
ASSERT_STREQ(name, "chargen");
ASSERT_EQ(localproto[0], proto2);
localproto[0] = NULL;
ASSERT_EQ(0, /* pick first matching protocol */
LookupServicesByPort(htons(19), localproto, name, sizeof(name),
"services"));
ASSERT_STREQ(name, "chargen");
ASSERT_NE(NULL, localproto[0]); /* got alloc'd during the call */
ASSERT_STREQ(localproto[0], "tcp");
free(localproto[0]);
}
TEST(LookupServicesByName, GetPortWhenNameOrAlias) {
char name[16]; /* sample has only names of length 3 */
char proto1[] = "tcp";
char proto2[] = "udp";
char* localproto[1];
localproto[0] = NULL;
ASSERT_EQ(
-1, /* non-existent name */
LookupServicesByName("http", localproto, name, sizeof(name), "services"));
ASSERT_EQ(NULL, localproto[0]);
localproto[0] = proto2;
ASSERT_EQ(
-1, /* name exists but wrong protocol */
LookupServicesByName("ssh", localproto, name, sizeof(name), "services"));
ASSERT_EQ(localproto[0], proto2);
localproto[0] = proto1;
ASSERT_EQ(
htons(22), /* in network byte order */
LookupServicesByName("ssh", localproto, name, sizeof(name), "services"));
ASSERT_STREQ(name, "ssh"); /* official name written to buffer */
ASSERT_EQ(localproto[0], proto1);
localproto[0] = proto2;
ASSERT_EQ(htons(19), /* works if alias provided */
LookupServicesByName("ttytst", localproto, name, sizeof(name),
"services"));
ASSERT_STREQ(name, "chargen"); /* official name written to buffer */
ASSERT_EQ(localproto[0], proto2);
localproto[0] = NULL;
ASSERT_EQ(htons(19), /* pick first matching protocol */
LookupServicesByName("source", localproto, name, sizeof(name),
"services"));
ASSERT_STREQ(name, "chargen");
ASSERT_NE(NULL, localproto[0]); /* got alloc'd during the call */
ASSERT_STREQ(localproto[0], "tcp");
free(localproto[0]);
}

1
test/libc/dns/test.mk
View file

@ -23,6 +23,7 @@ TEST_LIBC_DNS_CHECKS = \
$(TEST_LIBC_DNS_SRCS_TEST:%.c=o/$(MODE)/%.com.runs)
TEST_LIBC_DNS_DIRECTDEPS = \
LIBC_CALLS \
LIBC_DNS \
LIBC_FMT \
LIBC_INTRIN \