netrc: Implement .netrc parsing

src/Makefile.am

@@ -12,6 +12,8 @@ axel_SOURCES = \
 	src/ftp.h \
 	src/http.c \
 	src/http.h \
+	src/netrc.c \
+	src/netrc.h \
 	src/search.c \
 	src/search.h \
 	src/ssl.c \

src/conf.h

@@ -42,6 +42,8 @@
 #ifndef AXEL_CONF_H
 #define AXEL_CONF_H
 
+#include "netrc.h"
+
 typedef struct {
 	char default_filename[MAX_STRING];
 	char http_proxy[MAX_STRING];
@@ -67,6 +69,7 @@ typedef struct {
 	int search_threads;
 	int search_amount;
 	int search_top;
+	netrc_t *netrc;
 
 	unsigned io_timeout;
 

src/conn.c

@@ -122,7 +122,7 @@ conn_set(conn_t *conn, const char *set_url)
 		*conn->pass = 0;
 	} else {
 		/* If not: Fill in defaults */
-		if (PROTO_IS_FTP(conn->proto)) {
+		if (PROTO_IS_FTP(conn->proto) && !conn->conf->netrc) {
 			/* Dash the password: Save traffic by trying
 			   to avoid multi-line responses */
 			strcpy(conn->user, "anonymous");
@@ -161,6 +161,14 @@ conn_set(conn_t *conn, const char *set_url)
 		i = conn->host;
 	}
 
+	/* Uses .netrc info if enabled and creds have not been provided */
+	if (!conn->user || !*conn->user) {
+		netrc_parse(conn->conf->netrc, conn->host,
+			    conn->user, sizeof(conn->user),
+			    conn->pass, sizeof(conn->pass));
+	}
+	printf("host: %s, user: %s, pass: %s\n", conn->host, conn->user, conn->pass);
+
 	return conn->port > 0;
 }
 

src/netrc.c

@@ -0,0 +1,220 @@
+/*
+  Axel -- A lighter download accelerator for Linux and other Unices
+
+  Copyright 2019      David da Silva Polverari
+
+  This program is free software; you can redistribute it and/or
+  modify it under the terms of the GNU General Public License
+  as published by the Free Software Foundation; either version 2
+  of the License, or (at your option) any later version.
+
+  In addition, as a special exception, the copyright holders give
+  permission to link the code of portions of this program with the
+  OpenSSL library under certain conditions as described in each
+  individual source file, and distribute linked combinations including
+  the two.
+
+  You must obey the GNU General Public License in all respects for all
+  of the code used other than OpenSSL. If you modify file(s) with this
+  exception, you may extend this exception to your version of the
+  file(s), but you are not obligated to do so. If you do not wish to do
+  so, delete this exception statement from your version. If you delete
+  this exception statement from all source files in the program, then
+  also delete it here.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+/* .netrc parsing implementation */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include "axel.h"
+#include "netrc.h"
+
+struct netrc{
+	size_t sz;
+	char *s_addr;
+};
+
+typedef struct {
+	char *data;
+	size_t len;
+} buffer_t;
+
+static const char *tok_delim = " \t\n";
+
+// FIXME optimize
+static size_t
+memspn(const char *s, const char *accept, size_t len)
+{
+	size_t sz = 0;
+
+	while (*s && len-- && strchr(accept, *s++))
+		sz++;
+	return sz;
+}
+
+// FIXME optimize
+static size_t
+memcspn(const char *s, const char *reject, size_t len)
+{
+	size_t sz = 0;
+
+	while (*s && len--)
+		if (strchr(reject, *s))
+			return sz;
+		else
+			s++, sz++;
+	return sz;
+}
+
+static buffer_t
+memtok(const char *addr, size_t len, const char *delim, buffer_t *save_ptr)
+{
+	size_t sz;
+	char *p, *q;
+	buffer_t ret;
+
+	if (!addr) {
+		p = save_ptr->data;
+	} else {
+		p = (char *) addr;
+		save_ptr->len = len;
+	}
+	sz = memspn(p, delim, save_ptr->len);
+	p += sz;
+	save_ptr->len -= sz;
+	q = p;
+	sz = memcspn(q, delim, save_ptr->len);
+	q += sz;
+	save_ptr->data = q;
+	ret.len = q - p;
+	ret.data = p;
+	return ret;
+}
+
+static size_t
+netrc_mmap(const char *path, char **addr)
+{
+	const char *home = NULL;
+
+	if (!path || !*path)
+		path = getenv("NETRC");
+
+	if (!path) {
+		const char suffix[] = "/.netrc";
+
+		home = getenv("HOME");
+		if (!home)
+			return 0;
+
+		size_t i = strlen(home);
+		char *tmp = malloc(i + sizeof(suffix));
+		if (!tmp)
+			return 0;
+
+		memcpy(tmp, home, i);
+		memcpy(tmp + i, suffix, sizeof(suffix));
+		path = tmp;
+	}
+
+	int fd = open(path, O_RDONLY, 0);
+
+	if (home)
+		free((void*)path);
+
+	if (fd == -1)
+		return 0;
+
+	struct stat st;
+	fstat(fd, &st);
+
+	*addr = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE | MAP_POPULATE,
+		     fd, 0);
+
+	close(fd);
+	return st.st_size;
+}
+
+netrc_t *
+netrc_init(const char *path)
+{
+	netrc_t *netrc;
+
+	netrc = calloc(1, sizeof(netrc_t));
+	if (netrc) {
+		netrc->sz = netrc_mmap(path, &netrc->s_addr);
+		if (netrc->sz)
+			return netrc;
+		free(netrc);
+	}
+	return NULL;
+}
+
+void
+netrc_parse(netrc_t *netrc, const char *host, char *user, size_t user_len, char *pass, size_t pass_len)
+{
+	bool matched = false;
+	buffer_t tok, save_buf = {};
+	const struct parser {
+		const char * const key;
+		char *dst;
+		size_t len;
+	} parser[] = {
+		{ "login", user, user_len },
+		{ "password", pass, pass_len },
+		{ "machine", NULL, 0 },
+		{ "default", NULL, 0 },
+	};
+	enum { parser_len = sizeof(parser) / sizeof(*parser), };
+
+	if (!netrc)
+		return;
+
+	tok = memtok(netrc->s_addr, netrc->sz, tok_delim, &save_buf);
+	while (tok.len) {
+		const struct parser *p = parser;
+		while (p < parser + parser_len && strncmp(p->key, tok.data, tok.len))
+			p++;
+
+		/* unknown token? -> abort */
+		if (p >= parser + parser_len)
+			return;
+
+		/* next "machine"/"default" entry */
+		if (!p->dst) {
+			/* if we already got one, we're done */
+			if (matched)
+				break;
+			if (tok.data[0] == 'm') {
+				tok = memtok(NULL, 0, tok_delim, &save_buf);
+				matched = !strncmp(host, tok.data, tok.len);
+			} else {
+				matched = true;
+			}
+		} else {
+			tok = memtok(NULL, 0, tok_delim, &save_buf);
+			if (matched) {
+				// FIXME should we be aborting?
+				if (tok.len >= p->len)
+					tok.len = p->len - 1;
+				memcpy(p->dst, tok.data, tok.len);
+				p->dst[tok.len] = 0;
+			}
+		}
+		tok = memtok(NULL, 0, tok_delim, &save_buf);
+	}
+}

src/netrc.h

@@ -0,0 +1,47 @@
+/*
+  Axel -- A lighter download accelerator for Linux and other Unices
+
+  Copyright 2019      David da Silva Polverari
+
+  This program is free software; you can redistribute it and/or
+  modify it under the terms of the GNU General Public License
+  as published by the Free Software Foundation; either version 2
+  of the License, or (at your option) any later version.
+
+  In addition, as a special exception, the copyright holders give
+  permission to link the code of portions of this program with the
+  OpenSSL library under certain conditions as described in each
+  individual source file, and distribute linked combinations including
+  the two.
+
+  You must obey the GNU General Public License in all respects for all
+  of the code used other than OpenSSL. If you modify file(s) with this
+  exception, you may extend this exception to your version of the
+  file(s), but you are not obligated to do so. If you do not wish to do
+  so, delete this exception statement from your version. If you delete
+  this exception statement from all source files in the program, then
+  also delete it here.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+/* .netrc parsing include file */
+
+#ifndef AXEL_NETRC_H
+#define AXEL_NETRC_H
+
+typedef struct netrc netrc_t;
+
+netrc_t *netrc_init(const char *netrc_filename);
+void netrc_parse(netrc_t *netrc, const char *host,
+		 char *user, size_t user_len,
+		 char *pass, size_t pass_len);
+
+#endif				/* AXEL_NETRC_H */

src/text.c

@@ -71,6 +71,7 @@ static struct option axel_options[] = {
 	{"max-redirect",    1,      NULL, MAX_REDIR_OPT},
 	{"output",          1,      NULL, 'o'},
 	{"search",          2,      NULL, 'S'},
+	{"netrc",           2,      NULL, 'R'},
 	{"ipv4",            0,      NULL, '4'},
 	{"ipv6",            0,      NULL, '6'},
 	{"no-proxy",        0,      NULL, 'N'},
@@ -117,7 +118,7 @@ main(int argc, char *argv[])
 	j = -1;
 	while (1) {
 		int option = getopt_long(argc, argv,
-					 "s:n:o:S::46NqvhVakcH:U:T:",
+					 "s:n:o:S::R::46NqvhVakcH:U:T:",
 					 axel_options, NULL);
 		if (option == -1)
 			break;
@@ -161,6 +162,9 @@ main(int argc, char *argv[])
 				}
 			}
 			break;
+		case 'R':
+			conf->netrc = netrc_init(optarg);
+			break;
 		case '6':
 			conf->ai_family = AF_INET6;
 			break;
@@ -659,6 +663,7 @@ print_help(void)
 		 "-n x\tSpecify maximum number of connections\n"
 		 "-o f\tSpecify local output file\n"
 		 "-S[n]\tSearch for mirrors and download from n servers\n"
+		 "-R[file]\tRetrieve credentials from $HOME/.netrc file or filename\n"
 		 "-4\tUse the IPv4 protocol\n"
 		 "-6\tUse the IPv6 protocol\n"
 		 "-H x\tAdd HTTP header string\n"
@@ -682,6 +687,7 @@ print_help(void)
 		 "--max-redirect=x\t\tSpecify maximum number of redirections\n"
 		 "--output=f\t\t-o f\tSpecify local output file\n"
 		 "--search[=n]\t\t-S[n]\tSearch for mirrors and download from n servers\n"
+		 "--netrc[=file]\t\t-R[file]\tRetrieve credentials from $HOME/.netrc file or filename\n"
 		 "--ipv4\t\t\t-4\tUse the IPv4 protocol\n"
 		 "--ipv6\t\t\t-6\tUse the IPv6 protocol\n"
 		 "--header=x\t\t-H x\tAdd HTTP header string\n"