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#include <stdio.h>
#include <unistd.h>
#include <limits.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#define ARENA_IMPL
#define STR_IMPL
#include "arena.h"
#include "str.h"
/* address cache */
#define ADDR_MAP_MAX 128
#define ADDR_HOST_MAX 128
typedef struct {
char host[ADDR_HOST_MAX];
int hostn, port;
struct addrinfo *ai;
} AddrMap;
static AddrMap addr_mapv[ADDR_MAP_MAX];
static int addr_mapc = 0;
Str
uint_to_str(unsigned src, Arena *a)
{
Str r = { 0 };
do {
str_catc(&r, (src % 10) + '0', a);
src /= 10;
} while(src);
for (int i = 0, j = r.n - 1; i < j; i++, j--) {
char t = r.s[i];
r.s[i] = r.s[j];
r.s[j] = t;
}
return r;
}
struct addrinfo *
addr_get(Str host, int port, Arena *scratch)
{
if (host.n > ADDR_HOST_MAX) {
fprintf(stderr, "hostname too long\n");
return NULL;
}
/* TODO: maybe move fetched addr to front of table? */
for (int i = 0; i < addr_mapc; i++) {
AddrMap *m = &addr_mapv[i];
if (m->port != port) continue;
if (str_eql((Str) { m->host, m->hostn }, host))
return m->ai;
}
puts("lookup");
struct addrinfo *ai;
int e = getaddrinfo(str_to_cstr(host, scratch),
str_to_cstr(uint_to_str(port, scratch), scratch),
&(struct addrinfo) {
.ai_family = AF_INET,
.ai_socktype = SOCK_STREAM,
.ai_protocol = IPPROTO_TCP,
.ai_flags = AI_NUMERICSERV
}, &ai);
if (e) {
fprintf(stderr, "bad address: %s\n", gai_strerror(e));
return NULL;
}
if (addr_mapc == ADDR_MAP_MAX) {
freeaddrinfo(addr_mapv[0].ai);
for (int i = 1; i < ADDR_MAP_MAX; i++)
addr_mapv[i-1] = addr_mapv[i];
addr_mapc--;
}
AddrMap *m = &addr_mapv[addr_mapc++];
memcpy(m->host, host.s, host.n);
m->hostn = host.n;
m->port = port;
m->ai = ai;
return ai;
}
void
addr_init(void)
{
/* do nothing */
}
void
addr_fini(void)
{
for (int i = 0; i < addr_mapc; i++)
freeaddrinfo(addr_mapv[i].ai);
}
int
addr_conn(Str host, int port, Arena *scratch)
{
struct addrinfo *ai = addr_get(host, port, scratch);
if (!ai)
return -1;
int s = socket(AF_INET, SOCK_STREAM, 0);
if (s == -1) {
fprintf(stderr, "couldn't create socket\n");
return -1;
}
if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0) {
fprintf(stderr, "couldn't connect to host\n");
close(s);
return -1;
}
return s;
}
/* url parsing */
#define PROT_DEFAULT PROT_GOPHER
typedef enum {
PROT_UNKNOWN,
PROT_GOPHER,
PROT_FILE,
} Proto;
typedef enum {
GI_TEXT,
GI_MENU,
GI_SEARCH,
GI_UNSUPPORTED,
} GopherItemType;
typedef struct {
Str host, path;
Proto proto;
int port;
} Request;
int
parse_port(Str s) {
int x = 0;
for (int i = 0; i < s.n; i++) {
if (s.s[i] < '0' || s.s[i] > '9') return -1;
if (x >= INT_MAX / 10 - 1) return -1;
x = (x * 10) + s.s[i] - '0';
}
return x;
}
int
parse_request(Str url, Request *req)
{
int i;
static struct { Str s; Proto p; int port; } prot_tbl[] = {
{ Ss("gopher"), PROT_GOPHER, 70 },
{ Ss("file"), PROT_FILE, 0 },
};
/* protocol */
req->proto = PROT_UNKNOWN;
Cut cprot = str_cuts(url, S("://"));
if (cprot.tail.n > 0) {
for (i = 0; i < sizeof prot_tbl / sizeof *prot_tbl; i++) {
if (str_eql(cprot.head, prot_tbl[i].s)) {
req->proto = prot_tbl[i].p;
req->port = prot_tbl[i].port;
}
}
url = cprot.tail;
switch (req->proto) {
case PROT_UNKNOWN:
fprintf(stderr, "bad protocol\n");
return -1;
case PROT_FILE:
req->path = url;
return 0;
default:
break;
}
} else {
req->proto = PROT_DEFAULT;
}
/* host & port */
Cut chost = str_cut(url, '/');
Cut cport = str_cut(chost.head, ':');
req->path = chost.tail;
req->host = cport.head;
if (cport.tail.n > 0) {
req->port = parse_port(cport.tail);
if (req->port == -1) {
fprintf(stderr, "bad port\n");
return -1;
}
}
return 0;
}
int
main(void)
{
Arena scratch = { 0 };
Request req = { 0 };
addr_init();
printf("%d\n", parse_request(S("gopher://sdf.org/users/solderpunk"), &req));
printf("host = %.*s\n", (int)req.host.n, req.host.s);
printf("path = %.*s\n", (int)req.path.n, req.path.s);
printf("prot = %d\n", req.proto);
printf("port = %d\n", req.port);
int s = addr_conn(req.host, req.port, &scratch);
write(s, req.path.s, req.path.n);
write(s, "\r\n", 2);
for (;;) {
char buf[256];
int n = read(s, buf, 256);
if (n <= 0) break;
fwrite(buf, 1, n, stdout);
}
close(s);
addr_fini();
return 0;
}
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