support repos.conf files

Since the system is moving away from PORTDIR/etc... and to a more
flexible repos.conf setup, make sure we support that stuff.

This pulls in an external dependency which is new for us, but the
iniparser library is very small (<20k on x86_64), written in pure
C, and is used by big projects already (like samba).  Doing an NIH
thing here would be a waste of time.

URL: https://bugs.gentoo.org/540620
Reported-by: Elias Probst <mail@eliasprobst.eu>

3 files changed, 63 insertions, 7 deletions

diff --git a/Makefile b/Makefile
index 7304559..fe6092f 100644
--- a/Makefile
+++ b/Makefile
@@ -24,6 +24,7 @@ DBG_CFLAGS = -O0 -DEBUG -g3 -ggdb -fno-pie $(call check_gcc, -fsanitize=address
 #CFLAGS   += -Os -DOPTIMIZE_FOR_SIZE=2 -falign-functions=2 -falign-jumps=2 -falign-labels=2 -falign-loops=2
 #LDFLAGS  := -pie
 LIBADD    += $(shell echo | $(CC) -dM -E - | grep -q ' __FreeBSD__' && echo '-lkvm')
+LIBADD    += -liniparser
 DESTDIR   :=
 PREFIX    := $(DESTDIR)/usr
 STRIP     := strip
diff --git a/main.c b/main.c
index 29a889f..cb180df 100644
--- a/main.c
+++ b/main.c
@@ -421,6 +421,57 @@ contents_entry *contents_parse_line(char *line)
 	return &e;
 }
 
+/* Handle a single file in the repos.conf format. */
+static void read_one_repos_conf(const char *repos_conf)
+{
+	char *conf;
+	const char *repo, *path;
+	dictionary *dict;
+
+	dict = iniparser_load(repos_conf);
+
+	repo = iniparser_getstring(dict, "DEFAULT:main-repo", NULL);
+	if (repo) {
+		xasprintf(&conf, "%s:location", repo);
+		path = iniparser_getstring(dict, conf, NULL);
+		if (path) {
+			free(portdir);
+			portdir = xstrdup(path);
+		}
+		free(conf);
+	}
+
+	iniparser_freedict(dict);
+}
+
+/* Handle a possible directory of files. */
+static void read_repos_conf(const char *configroot, const char *repos_conf)
+{
+	char *top_conf, *sub_conf;
+	int i, count;
+	struct dirent **confs;
+
+	xasprintf(&top_conf, "%s%s", configroot, repos_conf);
+	count = scandir(top_conf, &confs, NULL, alphasort);
+	if (count == -1) {
+		if (errno == ENOTDIR)
+			read_one_repos_conf(top_conf);
+	} else {
+		for (i = 0; i < count; ++i) {
+			const char *name = confs[i]->d_name;
+
+			if (name[0] == '.' || confs[i]->d_type != DT_REG)
+				continue;
+
+			xasprintf(&sub_conf, "%s/%s", top_conf, name);
+			read_one_repos_conf(sub_conf);
+			free(sub_conf);
+		}
+		scandir_free(confs, count);
+	}
+	free(top_conf);
+}
+
 static void strincr_var(const char *name, const char *s, char **value, size_t *value_len)
 {
 	size_t len;
@@ -715,18 +766,18 @@ void initialize_portage_env(void)
 	}
 
 	/* figure out where to find our config files */
-	s = getenv("PORTAGE_CONFIGROOT");
-	if (!s)
-		s = "/";
+	const char *configroot = getenv("PORTAGE_CONFIGROOT");
+	if (!configroot)
+		configroot = "/";
 
 	/* walk all the stacked profiles */
-	read_portage_profile(s, CONFIG_EPREFIX "etc/make.profile", vars_to_read);
-	read_portage_profile(s, CONFIG_EPREFIX "etc/portage/make.profile", vars_to_read);
+	read_portage_profile(configroot, CONFIG_EPREFIX "etc/make.profile", vars_to_read);
+	read_portage_profile(configroot, CONFIG_EPREFIX "etc/portage/make.profile", vars_to_read);
 
 	/* now read all the config files */
 	read_portage_env_file("", CONFIG_EPREFIX "usr/share/portage/config/make.globals", vars_to_read);
-	read_portage_env_file(s, CONFIG_EPREFIX "etc/make.conf", vars_to_read);
-	read_portage_env_file(s, CONFIG_EPREFIX "etc/portage/make.conf", vars_to_read);
+	read_portage_env_file(configroot, CONFIG_EPREFIX "etc/make.conf", vars_to_read);
+	read_portage_env_file(configroot, CONFIG_EPREFIX "etc/portage/make.conf", vars_to_read);
 
 	/* finally, check the env */
 	for (i = 0; vars_to_read[i].name; ++i) {
@@ -826,6 +877,8 @@ void initialize_portage_env(void)
 		portroot[var->value_len + 1] = '\0';
 	}
 
+	read_repos_conf(configroot, CONFIG_EPREFIX "etc/portage/repos.conf");
+
 	if (getenv("PORTAGE_QUIET") != NULL)
 		quiet = 1;
 
diff --git a/porting.h b/porting.h
index 3235542..8045813 100644
--- a/porting.h
+++ b/porting.h
@@ -49,6 +49,8 @@
 #include <sys/time.h>
 #include <sys/types.h>
 
+#include <iniparser.h>
+
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(*(arr)))
 
 #ifndef BUFSIZE