Use an enumeration for TCP/UDP protocol instead of SOCK_STREAM/SOCK_DGRAM directly. Use a string table instead of direct string comparisons.

Author: someguy

src/netlog/netlog-manager.c

@@ -12,6 +12,7 @@
 #include "fd-util.h"
 #include "fileio.h"
 #include "string-util.h"
+#include "string-table.h"
 #include "parse-util.h"
 #include "netlog-manager.h"
 
@@ -26,6 +27,13 @@
 #define JOURNAL_FOREACH_DATA_RETVAL(j, data, l, retval)                     \
         for (sd_journal_restart_data(j); ((retval) = sd_journal_enumerate_data((j), &(data), &(l))) > 0; )
 
+static const char *const protocol_table[_SYSLOG_TRANSMISSION_PROTOCOL_MAX] = {
+        [SYSLOG_TRANSMISSION_PROTOCOL_UDP] = "udp",
+        [SYSLOG_TRANSMISSION_PROTOCOL_TCP] = "tcp",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(protocol, int);
+
 static int parse_field(const void *data, size_t length, const char *field, char **target) {
         size_t fl, nl;
         void *buf;

src/netlog/netlog-manager.h

@@ -7,6 +7,13 @@
 #include "sd-network.h"
 #include "socket-util.h"
 
+typedef enum SysLogTransmissionProtocol {
+        SYSLOG_TRANSMISSION_PROTOCOL_UDP      = 1 << 0,
+        SYSLOG_TRANSMISSION_PROTOCOL_TCP      = 1 << 1,
+        _SYSLOG_TRANSMISSION_PROTOCOL_MAX,
+        _SYSLOG_TRANSMISSION_PROTOCOL_INVALID = -EINVAL,
+} SysLogTransmissionProtocol;
+
 typedef struct Manager Manager;
 
 struct Manager {
@@ -33,7 +40,7 @@ struct Manager {
 
         char *last_cursor, *current_cursor;
         char *structured_data;
-        int protocol;
+        SysLogTransmissionProtocol protocol;
 };
 
 int manager_new(Manager **ret, const char *state_file, const char *cursor);
@@ -51,3 +58,6 @@ int manager_push_to_network(Manager *m, int severity, int facility,
                             const char *identifier, const char *message,
                             const char *hostname, const char *pid,
                             const struct timeval *tv);
+
+const char *protocol_to_string(int v) _const_;
+int protocol_from_string(const char *s) _pure_;

src/netlog/netlog-network.c

@@ -153,9 +153,14 @@ int manager_push_to_network(Manager *m,
         /* Ninth: message */
         IOVEC_SET_STRING(iov[n++], message);
 
-        /* Tenth: Newline message separator, if not implicitly terminated by end of UDP frame */
-        if (m->protocol == SOCK_DGRAM)
+        /* Tenth: Optional newline message separator, if not implicitly terminated by end of UDP frame */
+        if (SYSLOG_TRANSMISSION_PROTOCOL_TCP == m->protocol)
+                /* De facto standard: separate messages by a newline */
                 IOVEC_SET_STRING(iov[n++], "\n");
+        else if (SYSLOG_TRANSMISSION_PROTOCOL_UDP == m->protocol) {
+                /* Message is implicitly terminated by end of UDP packet */
+        } else
+                return -EPROTONOSUPPORT;
 
         return network_send(m, iov, n);
 }
@@ -175,7 +180,16 @@ int manager_open_network_socket(Manager *m) {
         if (!IN_SET(m->address.sockaddr.sa.sa_family, AF_INET, AF_INET6))
                 return -EAFNOSUPPORT;
 
-        m->socket = socket(m->address.sockaddr.sa.sa_family, m->protocol|SOCK_CLOEXEC, 0);
+        switch (m->protocol) {
+                case SYSLOG_TRANSMISSION_PROTOCOL_UDP:
+                        m->socket = socket(m->address.sockaddr.sa.sa_family, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+                        break;
+                case SYSLOG_TRANSMISSION_PROTOCOL_TCP:
+                        m->socket = socket(m->address.sockaddr.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+                        break;
+                default:
+                        return -EINVAL;
+        }
         if (m->socket < 0)
                 return -errno;
 
@@ -185,7 +199,7 @@ int manager_open_network_socket(Manager *m) {
                 goto fail;
         }
 
-        if (SOCK_STREAM == m->protocol) {
+        if (SYSLOG_TRANSMISSION_PROTOCOL_TCP == m->protocol) {
                 union sockaddr_union sa;
                 socklen_t salen;
                 switch (m->address.sockaddr.sa.sa_family) {