Factor out socket operations (Fixes #13)

1 files changed, 117 insertions, 0 deletions

diff --git a/backends/libmmbackend.c b/backends/libmmbackend.c
new file mode 100644
index 0000000..6320611
--- /dev/null
+++ b/backends/libmmbackend.c
@@ -0,0 +1,117 @@
+#include "libmmbackend.h"
+
+void mmbackend_parse_hostspec(char* spec, char** host, char** port){
+	size_t u = 0;
+
+	if(!spec || !host || !port){
+		return;
+	}
+
+	*port = NULL;
+
+	//skip leading spaces
+	for(; spec[u] && isspace(spec[u]); u++){
+	}
+
+	if(!spec[u]){
+		*host = NULL;
+		return;
+	}
+
+	*host = spec + u;
+
+	//scan until string end or space
+	for(; spec[u] && !isspace(spec[u]); u++){
+	}
+
+	//if space, the rest should be the port
+	if(spec[u]){
+		spec[u] = 0;
+		*port = spec + u + 1;
+	}
+}
+
+int mmbackend_parse_sockaddr(char* host, char* port, struct sockaddr_storage* addr, socklen_t* len){
+	struct addrinfo* head;
+	struct addrinfo hints = {
+		.ai_family = AF_UNSPEC
+	};
+
+	int error = getaddrinfo(host, port, &hints, &head);
+	if(error || !head){
+		fprintf(stderr, "Failed to parse address %s port %s: %s\n", host, port, gai_strerror(error));
+		return 1;
+	}
+
+	memcpy(addr, head->ai_addr, head->ai_addrlen);
+	if(len){
+		*len = head->ai_addrlen;
+	}
+
+	freeaddrinfo(head);
+	return 0;
+}
+
+int mmbackend_socket(char* host, char* port, int socktype, uint8_t listener){
+	int fd = -1, status, yes = 1, flags;
+	struct addrinfo hints = {
+		.ai_family = AF_UNSPEC,
+		.ai_socktype = socktype,
+		.ai_flags = (listener ? AI_PASSIVE : 0)
+	};
+	struct addrinfo *info, *addr_it;
+
+	status = getaddrinfo(host, port, &hints, &info);
+	if(status){
+		fprintf(stderr, "Failed to parse address %s port %s: %s\n", host, port, gai_strerror(status));
+		return -1;
+	}
+
+	//traverse the result list
+	for(addr_it = info; addr_it; addr_it = addr_it->ai_next){
+		fd = socket(addr_it->ai_family, addr_it->ai_socktype, addr_it->ai_protocol);
+		if(fd < 0){
+			continue;
+		}
+
+		//set required socket options
+		yes = 1;
+		if(setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (void*)&yes, sizeof(yes)) < 0){
+			fprintf(stderr, "Failed to enable SO_REUSEADDR on socket\n");
+		}
+
+		yes = 1;
+		if(setsockopt(fd, SOL_SOCKET, SO_BROADCAST, (void*)&yes, sizeof(yes)) < 0){
+			fprintf(stderr, "Failed to enable SO_BROADCAST on socket\n");
+		}
+
+		yes = 0;
+		if(setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, (void*)&yes, sizeof(yes)) < 0){
+			fprintf(stderr, "Failed to disable IP_MULTICAST_LOOP on socket: %s\n", strerror(errno));
+		}
+
+		status = bind(fd, addr_it->ai_addr, addr_it->ai_addrlen);
+		if(status < 0){
+			close(fd);
+			continue;
+		}
+
+		break;
+	}
+	freeaddrinfo(info);
+
+	if(!addr_it){
+		fprintf(stderr, "Failed to create socket for %s port %s\n", host, port);
+		return -1;
+	}
+
+	//set nonblocking
+	flags = fcntl(fd, F_GETFL, 0);
+	if(fcntl(fd, F_SETFL, flags | O_NONBLOCK) < 0){
+		fprintf(stderr, "Failed to set socket nonblocking\n");
+		close(fd);
+		return -1;
+	}
+
+	return fd;
+}