Allow disabling of internal (libdownload) code

Add a new --disable-internal-download flag to configure allowing the
internal download code to be skipped. This will be helpful on platforms that
currently don't support either libdownload or libfetch (such as Cygwin) and
for just compiling a lighter weight pacman binary.

This was made really easy by our recent refactoring of the download code
into separate internal and external functions, as well as some error code
cleanup.

Signed-off-by: Dan McGee <dan@archlinux.org>

1 files changed, 45 insertions, 27 deletions

diff --git a/lib/libalpm/dload.c b/lib/libalpm/dload.c
index ceaf2743..0977eea0 100644
--- a/lib/libalpm/dload.c
+++ b/lib/libalpm/dload.c
@@ -24,7 +24,9 @@
 #include <errno.h>
 #include <string.h>
 #include <unistd.h>
+#if defined(INTERNAL_DOWNLOAD)
 #include <download.h> /* libdownload */
+#endif
 
 /* libalpm */
 #include "dload.h"
@@ -34,30 +36,6 @@
 #include "util.h"
 #include "handle.h"
 
-/* Build a 'struct url' from an url. */
-static struct url *url_for_string(const char *url)
-{
-	struct url *ret = NULL;
-	ret = downloadParseURL(url);
-	if(!ret) {
-		_alpm_log(PM_LOG_ERROR, _("url '%s' is invalid\n"), url);
-		RET_ERR(PM_ERR_SERVER_BAD_URL, NULL);
-	}
-
-	/* if no URL scheme specified, assume HTTP */
-	if(strlen(ret->scheme) == 0) {
-		_alpm_log(PM_LOG_WARNING, _("url scheme not specified, assuming HTTP\n"));
-		strcpy(ret->scheme, SCHEME_HTTP);
-	}
-	/* add a user & password for anonymous FTP */
-	if(strcmp(ret->scheme,SCHEME_FTP) == 0 && strlen(ret->user) == 0) {
-		strcpy(ret->user, "anonymous");
-		strcpy(ret->pwd, "libalpm@guest");
-	}
-
-	return(ret);
-}
-
 static char *get_filename(const char *url) {
 	char *filename = strrchr(url, '/');
 	if(filename != NULL) {
@@ -86,6 +64,31 @@ static char *get_tempfile(const char *path, const char *filename) {
 	return(tempfile);
 }
 
+#if defined(INTERNAL_DOWNLOAD)
+/* Build a 'struct url' from an url. */
+static struct url *url_for_string(const char *url)
+{
+	struct url *ret = NULL;
+	ret = downloadParseURL(url);
+	if(!ret) {
+		_alpm_log(PM_LOG_ERROR, _("url '%s' is invalid\n"), url);
+		RET_ERR(PM_ERR_SERVER_BAD_URL, NULL);
+	}
+
+	/* if no URL scheme specified, assume HTTP */
+	if(strlen(ret->scheme) == 0) {
+		_alpm_log(PM_LOG_WARNING, _("url scheme not specified, assuming HTTP\n"));
+		strcpy(ret->scheme, SCHEME_HTTP);
+	}
+	/* add a user & password for anonymous FTP */
+	if(strcmp(ret->scheme,SCHEME_FTP) == 0 && strlen(ret->user) == 0) {
+		strcpy(ret->user, "anonymous");
+		strcpy(ret->pwd, "libalpm@guest");
+	}
+
+	return(ret);
+}
+
 static int download_internal(const char *url, const char *localpath,
 		time_t mtimeold, time_t *mtimenew) {
 	FILE *dlf, *localf = NULL;
@@ -230,6 +233,7 @@ cleanup:
 	downloadFreeURL(fileurl);
 	return(ret);
 }
+#endif
 
 static int download_external(const char *url, const char *localpath,
 		time_t mtimeold, time_t *mtimenew) {
@@ -242,9 +246,13 @@ static int download_external(const char *url, const char *localpath,
 	char cwd[PATH_MAX];
 	char *destfile, *tempfile, *filename;
 
+	if(!handle->xfercommand) {
+		RET_ERR(PM_ERR_EXTERNAL_DOWNLOAD, -1);
+	}
+
 	filename = get_filename(url);
 	if(!filename) {
-		return(-1);
+		RET_ERR(PM_ERR_EXTERNAL_DOWNLOAD, -1);
 	}
 	destfile = get_destfile(localpath, filename);
 	tempfile = get_tempfile(localpath, filename);
@@ -275,7 +283,7 @@ static int download_external(const char *url, const char *localpath,
 	getcwd(cwd, PATH_MAX);
 	if(chdir(localpath)) {
 		_alpm_log(PM_LOG_WARNING, _("could not chdir to %s\n"), localpath);
-		pm_errno = PM_ERR_CONNECT_FAILED;
+		pm_errno = PM_ERR_EXTERNAL_DOWNLOAD;
 		ret = -1;
 		goto cleanup;
 	}
@@ -285,7 +293,7 @@ static int download_external(const char *url, const char *localpath,
 
 	if(retval == -1) {
 		_alpm_log(PM_LOG_WARNING, _("running XferCommand: fork failed!\n"));
-		pm_errno = PM_ERR_FORK_FAILED;
+		pm_errno = PM_ERR_EXTERNAL_DOWNLOAD;
 		ret = -1;
 	} else if(retval != 0) {
 		/* download failed */
@@ -331,8 +339,18 @@ static int download(const char *url, const char *localpath,
 		return(ret ? -1 : 0);
 	}
 
+	/* We have a few things to take into account here.
+	 * 1. If we have both internal/external available, choose based on
+	 * whether xfercommand is populated.
+	 * 2. If we only have external available, we should first check
+	 * if a command was provided before we drop into download_external.
+	 */
 	if(handle->xfercommand == NULL) {
+#if defined(INTERNAL_DOWNLOAD)
 		ret = download_internal(url, localpath, mtimeold, mtimenew);
+#else
+		RET_ERR(PM_ERR_EXTERNAL_DOWNLOAD, -1);
+#endif
 	} else {
 		ret = download_external(url, localpath, mtimeold, mtimenew);
 	}