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#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include "net.h"
#include "err.h"
#include "doc.h"
int net_addr(const char *url, struct addr *adr, enum protocol prot_default) {
char *prot_mark;
if ((prot_mark = strstr(url, "://"))) {
static struct {
const char *str;
enum protocol prot;
} prot_str_tbl[] = {
{ "gopher", PROT_GOPHER },
{ "gemini", PROT_GEMINI },
{ "file", PROT_FILE },
};
size_t n = prot_mark - url;
adr->prot = PROT_UNKNOWN;
for (size_t i = 0; i < sizeof prot_str_tbl / sizeof *prot_str_tbl; i++) {
if (!strncmp(prot_str_tbl[i].str, url, n)) {
adr->prot = prot_str_tbl[i].prot;
break;
}
}
url = prot_mark + 3;
} else {
adr->prot = prot_default;
}
if (adr->prot == PROT_FILE) {
adr->host_len = 0;
size_t n = strlen(url);
if (n >= PATH_MAX) return -1;
adr->path_len = n;
memcpy(adr->path, url, n + 1);
} else {
adr->host_len = 0;
while (*url && *url != '/' && adr->host_len < HOST_MAX) {
adr->host[adr->host_len++] = *url++;
}
adr->host[adr->host_len] = 0;
char *colon = strchr(adr->host, ':');
if (colon) {
errno = 0;
int port = strtoul(colon + 1, NULL, 10);
if (errno) {
return -1;
} else {
adr->port = port;
}
*colon = 0;
adr->host_len = colon - adr->host;
} else {
switch (adr->prot) {
case PROT_GOPHER:
adr->port = 70;
break;
default:
adr->port = -1;
break;
}
}
if (*url && *url != '/') {
perr("hostname too long");
return -1;
}
if (*url) url++;
adr->path_len = 0;
while (*url && adr->path_len < HOST_MAX) {
adr->path[adr->path_len++] = *url++;
}
adr->path[adr->path_len] = 0;
if (*url) {
perr("path too long");
return -1;
}
}
return 0;
}
static long
net_hosttoaddr(const char *hostname)
{
struct hostent *h;
struct in_addr **al;
h = gethostbyname(hostname);
if (!h) {
perr("host not found");
return -1;
}
al = (struct in_addr **)h->h_addr_list;
if (!al || !(*al))
perr("empty host address");
return (*al)->s_addr;
}
static int
net_conntohost(const char *hostname, int port)
{
struct sockaddr_in sai;
int s;
s = socket(AF_INET, SOCK_STREAM, 0);
if (!s)
return -1;
sai.sin_family = AF_INET;
sai.sin_port = htons(port);
sai.sin_addr.s_addr = net_hosttoaddr(hostname);
if (connect(s, (struct sockaddr *)&sai, sizeof(sai)))
return -1;
return s;
}
static int fetch_file(const struct addr *adr, struct buf *buf, enum doc_type *doct) {
FILE *f = fopen(adr->path, "r/o");
if (!f) {
perr("file not found");
return -1;
}
buf_init(buf, 1024);
char b[256];
while (fgets(b, sizeof b, f)) {
buf_cat(buf, b, strlen(b));
}
buf_catc(buf, 0);
fclose(f);
*doct = DOC_PLAIN;
return 0;
}
static int fetch_gopher(const struct addr *adr, struct buf *buf, enum doc_type *doct) {
const char *sel = adr->path;
size_t sel_len = adr->path_len;
if (sel_len > 0 && sel[0] == '/') {
sel_len--;
sel++;
}
if (sel_len > 0) {
switch (*sel) {
case '0':
*doct = DOC_PLAIN;
break;
case '1':
*doct = DOC_GOPHERMAP;
break;
default:
perr("invalid item type");
return -1;
}
sel++;
sel_len--;
} else {
*doct = DOC_GOPHERMAP;
}
int s = net_conntohost(adr->host, adr->port);
if (s < 0) {
return -1;
}
if (write(s, sel, sel_len) < 0
|| write(s, "\r\n", 2) < 0) {
perr("write failure");
return -1;
}
buf_init(buf, 64);
char inbuf[256];
for (;;) {
ssize_t n = read(s, inbuf, sizeof inbuf);
if (n < 0) {
perr("read error");
buf_free(buf);
close(s);
return -1;
}
if (!n) break;
buf_cat(buf, inbuf, n);
}
close(s);
return 0;
}
int net_fetch(const struct addr *adr, struct buf *buf, enum doc_type *doct) {
switch (adr->prot) {
case PROT_FILE:
return fetch_file(adr, buf, doct);
case PROT_GOPHER:
return fetch_gopher(adr, buf, doct);
default:
perr("unsupported protocol");
return -1;
}
}
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