From 84c54c550481d8b38514b1165f6403e2e5c251db Mon Sep 17 00:00:00 2001
From: Kim Woelders <kim@woelders.dk>
Date: Sun, 12 Feb 2023 22:15:26 +0100
Subject: [PATCH] socket: Add server socket fucntions

About to be used in test code.
---
 lib/nvt_socket.c | 136 ++++++++++++++++++++++++++++++++++++++++-------
 lib/nvt_socket.h |   3 ++
 2 files changed, 119 insertions(+), 20 deletions(-)

diff --git a/lib/nvt_socket.c b/lib/nvt_socket.c
index 783dcca..2ab2e32 100644
--- a/lib/nvt_socket.c
+++ b/lib/nvt_socket.c
@@ -12,14 +12,19 @@
 #include "nvt_socket.h"
 
 
-int socket_create_client(const char *addr)
-{
-    char            host[64], port[64];
-    struct hostent *server;
-    struct sockaddr_in serveraddr;
-    int             sockfd, err;
+typedef struct {
+    unsigned short  type;       // socket type
+    unsigned short  slen;       // sockaddr length
+    union {
+        struct sockaddr gen;
+        struct sockaddr_in ipv4;
+    };
+} sa_t;
 
-    sscanf(addr, "%63[^:]:%63s", host, port);
+
+static int _sa_host_lookup(sa_t * sa, const char *host)
+{
+    struct hostent *server;
 
     server = gethostbyname(host);
     if (server == NULL)
@@ -28,26 +33,117 @@ int socket_create_client(const char *addr)
         return -1;
     }
 
-    sockfd = socket(AF_INET, SOCK_STREAM, 0);
-    if (sockfd < 0)
+    sa->slen = sizeof(sa->ipv4);
+
+    sa->ipv4.sin_family = AF_INET;
+    memcpy(&sa->ipv4.sin_addr.s_addr, server->h_addr, server->h_length);
+
+    return 0;
+}
+
+static int _sa_addr_parse(sa_t * sa, const char *addr)
+{
+    char            host[64], port[64];
+
+    memset(sa, 0, sizeof(sa_t));
+
+    sscanf(addr, "%63[^:]:%63s", host, port);
+
+    if (_sa_host_lookup(sa, host) != 0)
+        return -1;
+
+    sa->type = SOCK_STREAM;
+    sa->ipv4.sin_port = htons(atoi(port));
+
+    return 0;
+}
+
+int socket_create_client(const char *addr)
+{
+    sa_t            sa;
+    int             fd, err;
+
+    if (_sa_addr_parse(&sa, addr) != 0)
+        return -1;
+
+    fd = socket(sa.gen.sa_family, sa.type, 0);
+    if (fd < 0)
     {
-        nvt_log(LOG_ERR, "Socket open failed: %m\n");
-        return sockfd;
+        nvt_log(LOG_ERR, "%s: Could not find address: '%s'", __func__, addr);
+        return fd;
     }
 
-    bzero((char *)&serveraddr, sizeof(serveraddr));
-    serveraddr.sin_family = AF_INET;
-    bcopy((char *)server->h_addr, (char *)&serveraddr.sin_addr.s_addr,
-          server->h_length);
-    serveraddr.sin_port = htons(atoi(port));
-
-    err = connect(sockfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr));
+    err = connect(fd, &sa.gen, sa.slen);
     if (err < 0)
     {
         nvt_log(LOG_ERR, "Failed to connect to: %s: %m\n", addr);
-        close(sockfd);
+        close(fd);
         return -1;
     }
 
-    return sockfd;
+    return fd;
+}
+
+int socket_create_server(const char *addr)
+{
+    sa_t            sa;
+    int             err, fd, opt;
+
+    err = _sa_addr_parse(&sa, addr);
+    if (err != 0)
+    {
+        nvt_log(LOG_ERR, "%s: Could not find address: '%s'", __func__, addr);
+        return -1;
+    }
+
+    fd = socket(sa.gen.sa_family, sa.type, 0);
+    if (fd < 0)
+    {
+        nvt_log(LOG_ERR, "%s: *** socket(%s): %m", __func__, addr);
+        return -1;
+    }
+
+    if (sa.gen.sa_family == AF_INET)
+    {
+        /* Avoid TIME_WAIT state on socket close */
+        opt = 1;
+        setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
+    }
+
+    err = bind(fd, &sa.gen, sa.slen);
+    if (err != 0)
+    {
+        nvt_log(LOG_ERR, "%s: *** bind(%s): %m", __func__, addr);
+        close(fd);
+        return -1;
+    }
+
+    if (sa.type == SOCK_STREAM)
+    {
+        err = listen(fd, 5);
+        if (err != 0)
+        {
+            nvt_log(LOG_ERR, "%s: *** listen(%s): %m", __func__, addr);
+            close(fd);
+            return -1;
+        }
+    }
+
+    return fd;
+}
+
+int socket_create_server_client(int sfd)
+{
+    int             cfd;
+    socklen_t       slen;
+
+    slen = 0;
+    cfd = accept(sfd, NULL, &slen);
+    if (cfd < 0)
+    {
+        nvt_log(LOG_ERR, "%s: *** accept(): %m", __func__);
+        return -1;
+    }
+
+    return cfd;
 }
diff --git a/lib/nvt_socket.h b/lib/nvt_socket.h
index 30ecc0e..cb4b4ff 100644
--- a/lib/nvt_socket.h
+++ b/lib/nvt_socket.h
@@ -6,4 +6,7 @@
 
 int             socket_create_client(const char *addr);
 
+int             socket_create_server(const char *addr);
+int             socket_create_server_client(int sfd);
+
 #endif /* NVT_SOCKET_H */