Add support for syslog over TCP.

Author: someguy

conf/systemd-netlogd.conf.in

@@ -1,2 +1,3 @@
 [Network]
 #Address=239.0.0.1:6000
+#SocketType=udp

src/netlog/netlog-conf.c

@@ -4,6 +4,7 @@
 #include "in-addr-util.h"
 #include "netlog-conf.h"
 #include "conf-parser.h"
+#include "string-util.h"
 
 int config_parse_netlog_remote_address(const char *unit,
                                        const char *filename,
@@ -33,6 +34,36 @@ int config_parse_netlog_remote_address(const char *unit,
         return 0;
 }
 
+int config_parse_socket_type(const char *unit,
+                             const char *filename,
+                             unsigned line,
+                             const char *section,
+                             unsigned section_line,
+                             const char *lvalue,
+                             int ltype,
+                             const char *rvalue,
+                             void *data,
+                             void *userdata) {
+        Manager *m = userdata;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        if (strcaseeq(rvalue, "tcp"))
+                m->socket_type = SOCK_STREAM;
+        else if (strcaseeq(rvalue, "udp"))
+                m->socket_type = SOCK_DGRAM;
+        else {
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL,
+                           "Unrecognised socket type '%s'; should be either 'tcp' or 'udp'", rvalue);
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
 int manager_parse_config_file(Manager *m) {
         assert(m);
 

src/netlog/netlog-conf.h

@@ -17,4 +17,14 @@ int config_parse_netlog_remote_address(const char *unit,
                                        const char *rvalue,
                                        void *data,
                                        void *userdata);
+int config_parse_socket_type(const char *unit,
+                             const char *filename,
+                             unsigned line,
+                             const char *section,
+                             unsigned section_line,
+                             const char *lvalue,
+                             int ltype,
+                             const char *rvalue,
+                             void *data,
+                             void *userdata);
 int manager_parse_config_file(Manager *m);

src/netlog/netlog-gperf.gperf

@@ -16,4 +16,5 @@ struct ConfigPerfItem;
 %includes
 %%
 Network.Address,  config_parse_netlog_remote_address, 0, 0
+Network.SocketType,  config_parse_socket_type, 0, offsetof(Manager, socket_type)
 Network.StructuredData,  config_parse_string, 0, offsetof(Manager, structured_data)

src/netlog/netlog-manager.h

@@ -33,6 +33,7 @@ struct Manager {
 
         char *last_cursor, *current_cursor;
         char *structured_data;
+        int socket_type;
 };
 
 int manager_new(Manager **ret, const char *state_file, const char *cursor);

src/netlog/netlog-network.c

@@ -3,6 +3,7 @@
 #include <unistd.h>
 #include <stddef.h>
 #include <poll.h>
+#include <netinet/tcp.h>
 
 #include "netlog-manager.h"
 #include "io-util.h"
@@ -97,7 +98,7 @@ int manager_push_to_network(Manager *m,
         char header_priority[sizeof("<   >1 ")];
         char header_time[FORMAT_TIMESTAMP_MAX];
         uint8_t makepri;
-        struct iovec iov[13];
+        struct iovec iov[14];
         int n = 0;
 
         assert(m);
@@ -152,6 +153,10 @@ 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->socket_type == SOCK_DGRAM)
+                IOVEC_SET_STRING(iov[n++], "\n");
+
         return network_send(m, iov, n);
 }
 
@@ -170,7 +175,7 @@ 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, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+        m->socket = socket(m->address.sockaddr.sa.sa_family, m->socket_type|SOCK_CLOEXEC, 0);
         if (m->socket < 0)
                 return -errno;
 
@@ -180,6 +185,45 @@ int manager_open_network_socket(Manager *m) {
                 goto fail;
         }
 
+        if (SOCK_STREAM == m->socket_type) {
+                union sockaddr_union sa;
+                socklen_t salen;
+                switch (m->address.sockaddr.sa.sa_family) {
+                        case AF_INET:
+                                sa = (union sockaddr_union) {
+                                        .in.sin_family = m->address.sockaddr.sa.sa_family,
+                                        .in.sin_port = m->address.sockaddr.in.sin_port,
+                                        .in.sin_addr = m->address.sockaddr.in.sin_addr,
+                                };
+                                salen = sizeof(sa.in);
+                                break;
+                        case AF_INET6:
+                                sa = (union sockaddr_union) {
+                                        .in6.sin6_family = m->address.sockaddr.sa.sa_family,
+                                        .in6.sin6_port = m->address.sockaddr.in6.sin6_port,
+                                        .in6.sin6_addr = m->address.sockaddr.in6.sin6_addr,
+                                };
+                                salen = sizeof(sa.in6);
+                                break;
+                        default:
+                                r = -EAFNOSUPPORT;
+                                goto fail;
+                }
+                r = connect(m->socket, &m->address.sockaddr.sa, salen);
+                if (r < 0) {
+                        r = -errno;
+                        goto fail;
+                }
+
+                r = setsockopt(m->socket, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one));
+                if (r < 0)
+                        return r;
+        }
+
+        r = fd_status_flag(m->socket, O_NONBLOCK, 1);
+        if (r < 0)
+                goto fail;
+
         return m->socket;
 
  fail:

src/share/fd-util.c

@@ -121,6 +121,29 @@ int fd_cloexec(int fd, bool cloexec) {
         return 0;
 }
 
+int fd_status_flag(int fd, int flag, bool new_value) {
+        int flags, nflags;
+
+        assert(fd >= 0);
+
+        flags = fcntl(fd, F_GETFL, 0);
+        if (flags < 0)
+                return -errno;
+
+        if (new_value)
+                nflags = flags | flag;
+        else
+                nflags = flags & ~flag;
+
+        if (nflags == flags)
+                return 0;
+
+        if (fcntl(fd, F_SETFL, nflags) < 0)
+                return -errno;
+
+        return 0;
+}
+
 void stdio_unset_cloexec(void) {
         fd_cloexec(STDIN_FILENO, false);
         fd_cloexec(STDOUT_FILENO, false);

src/share/fd-util.h

@@ -38,6 +38,7 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(DIR*, closedir);
 #define _cleanup_close_pair_ _cleanup_(close_pairp)
 
 int fd_cloexec(int fd, bool cloexec);
+int fd_status_flag(int fd, int flag, bool new_value);
 void stdio_unset_cloexec(void);