server: Support sendat, protocol version 4

1 files changed, 115 insertions, 0 deletions

diff --git a/config.c b/config.c
new file mode 100644
index 0000000..bd7f822
--- /dev/null
+++ b/config.c
@@ -0,0 +1,115 @@
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+#include "config.h"
+#include "global.h"
+
+
+struct config_data {
+	size_t num_apikeys;
+	char **apikeys;
+	struct apikey_perm *apikey_perms;
+};
+
+static struct config_data config_data;
+
+static void add_apikey(char *key, struct apikey_perm perm) {
+	// This is slow, but optimisation is not worth it
+	config_data.num_apikeys++;
+	config_data.apikeys = realloc(config_data.apikeys, config_data.num_apikeys, char*);
+	config_data.apikey_perms =
+		realloc(config_data.apikey_perms, config_data.num_apikeys, struct apikey_perm);
+
+	config_data.apikeys[config_data.num_apikeys - 1] = key;
+	config_data.apikey_perms[config_data.num_apikeys - 1] = perm;
+}
+
+struct slice {
+	const char *s;
+	size_t len;
+};
+
+static struct slice next_word(struct slice *line) {
+	size_t cursor = 0;
+	while (cursor < line->len && isspace(line->s[cursor])) cursor++;
+	const size_t start = cursor;
+	while (cursor < line->len && !isspace(line->s[cursor])) cursor++;
+	const struct slice word = (struct slice){line->s + start, cursor - start};
+	line->s += cursor;
+	line->len -= cursor;
+	return word;
+}
+
+static void apply_config_line(const char *linebuf, size_t linelen) {
+	struct slice line = (struct slice){linebuf, linelen};
+	struct slice cmd = next_word(&line);
+	if (cmd.len == 0) return;
+
+	if (cmd.len == 6 && memcmp(cmd.s, "apikey", 6) == 0) {
+		struct slice key = next_word(&line);
+		struct slice pbits = next_word(&line);
+		if (line.len > 0) die("Too many fields on 'apikey' line");
+
+		for (size_t i = 0; i < pbits.len; i++) {
+			if (pbits.s[i] != '0' && pbits.s[i] != '1') {
+				die("Invalid permission bit '%c' on 'apikey' line", pbits.s[i]);
+			}
+		}
+
+		if (pbits.len != 1) die("Incorrect permission bit vector length on 'apikey' line");
+		struct apikey_perm perm;
+		perm.sendat = pbits.s[0] == '1';
+
+		for (size_t i = 0; i < key.len; i++) {
+			if (key.s[i] == '\0') die("Invalid null byte in key on 'apikey' line");
+		}
+
+		char *keystr = malloc(key.len + 1, char);
+		memcpy(keystr, key.s, key.len);
+		keystr[key.len] = '\0';
+
+		add_apikey(keystr, perm);
+	} else {
+		char *cmdstr = malloc(cmd.len + 1, char);
+		memcpy(cmdstr, cmd.s, cmd.len);
+		cmdstr[cmd.len] = '\0';
+		die("Unknown command '%s' in config file", cmdstr);
+	}
+}
+
+void config_init(const char *filename) {
+	FILE *f = fopen(filename, "r");
+	if (!f) die("Cannot open config file '%s'", filename);
+
+	char *line = NULL;
+	size_t linecap = 0;
+	ssize_t nr;
+	while ((nr = getline(&line, &linecap, f)) >= 0) {
+		if (line[0] == '#') continue;
+		if (nr > 0 && line[nr - 1] == '\n') nr--;
+		if (nr > 0 && line[nr - 1] == '\r') nr--;
+		apply_config_line(line, nr);
+	}
+	free(line);
+
+	if (!feof(f) && ferror(f)) {
+		die("Error reading config file '%s': %s", filename, strerror(errno));
+	}
+
+	fprintf(stderr, "config: Registered %zu API key%s\n",
+			config_data.num_apikeys, config_data.num_apikeys == 1 ? "" : "s");
+}
+
+struct apikey_perm config_check_apikey(const char *apikey) {
+	for (size_t i = 0; i < config_data.num_apikeys; i++) {
+		if (strcmp(config_data.apikeys[i], apikey) == 0) {
+			return config_data.apikey_perms[i];
+		}
+	}
+
+	// Unknown key means no permissions
+	struct apikey_perm perm;
+	memset(&perm, 0, sizeof perm);
+	return perm;
+}